Thursday, 31 May 2012

Pramipexole Accord 1.1 mg tablets





1. Name Of The Medicinal Product



Pramipexole Accord 1.1 mg tablets


2. Qualitative And Quantitative Composition



Each tablet contains 1.5 mg pramipexole dihydrochloride monohydrate equivalent to 1.1 mg pramipexole.



Please note:



Pramipexole doses as published in the literature refer to the salt form.



Therefore, doses will be expressed in terms of both pramipexole base and pramipexole salt (in brackets).



For a full list of excipients, see section 6.1.



3. Pharmaceutical Form



Tablet.



The tablets are white to off-white, round, flat faced, bevel edged, with inscription 'I' and '5' on either side of the breakline on one side and breakline on other side.



The tablets can be divided into two equal halves.



4. Clinical Particulars



4.1 Therapeutic Indications



Pramipexole Accord is indicated in adults for treatment of the signs and symptoms of idiopathic Parkinson's disease, alone (without levodopa) or in combination with levodopa, i.e. over the course of the disease, through to late stages when the effect of levodopa wears off or becomes inconsistent and fluctuations of the therapeutic effect occur (end of dose or “on off” fluctuations).



Pramipexole Accord is indicated in adults for symptomatic treatment of moderate to severe idiopathic Restless Legs Syndrome in doses up to 0.54 mg of base (0.75 mg of salt) (see section 4.2).



4.2 Posology And Method Of Administration



Posology



Parkinson's disease



The daily dose is administered in equally divided doses 3 times a day.



Initial treatment



Doses should be increased gradually from a starting dose of 0.264 mg of base (0.375 mg of salt) per day and then increased every 5-7 days. Providing patients do not experience intolerable undesirable effects, the dose should be titrated to achieve a maximal therapeutic effect.





























Ascending dose schedule of Pramipexole Accord


    


Week




Dose (mg of base)




Total Daily Dose (mg of base)




Dose (mg of salt)




Total Daily Dose (mg of salt)




1




3 x 0.088




0.264




3 x 0.125




0.375




2




3 x 0.18




0.54




3 x 0.25




0.75




3




3 x 0.35




1.1




3 x 0.5




1.50



If a further dose increase is necessary the daily dose should be increased by 0.54 mg of base (0.75 mg of salt) at weekly intervals up to a maximum dose of 3.3 mg of base (4.5 mg of salt) per day. However, it should be noted that the incidence of somnolence is increased at doses higher than 1.5 mg (of salt) per day (see section 4.8).



Maintenance treatment



The individual dose of pramipexole should be in the range of 0.264 mg of base (0.375 mg of salt) to a maximum of 3.3 mg of base (4.5 mg of salt) per day. During dose escalation in pivotal studies, efficacy was observed starting at a daily dose of 1.1 mg of base (1.5 mg of salt). Further dose adjustments should be done based on the clinical response and the occurrence of adverse reactions. In clinical trials approximately 5% of patients were treated at doses below 1.1 mg of base (1.5 mg of salt). In advanced Parkinson's disease, pramipexole doses higher than 1.1 mg of base (1.5 mg of salt) per day can be useful in patients where a reduction of the levodopa therapy is intended. It is recommended that the dose of levodopa is reduced during both the dose escalation and the maintenance treatment with Pramipexole Accord, depending on reactions in individual patients (see section 4.5).



Treatment discontinuation



Abrupt discontinuation of dopaminergic therapy can lead to the development of a neuroleptic malignant syndrome. Pramipexole should be tapered off at a rate of 0.54 mg of base (0.75 mg of salt) per day until the daily dose has been reduced to 0.54 mg of base (0.75 mg of salt). Thereafter the dose should be reduced by 0.264 mg of base (0.375 mg of salt) per day (see section 4.4).



Dosing in patients with renal impairment



The elimination of pramipexole is dependent on renal function. The following dose schedule is suggested for initiation of therapy:



Patients with a creatinine clearance above 50 ml/min require no reduction in daily dose or dosing frequency.



In patients with a creatinine clearance between 20 and 50 ml/min, the initial daily dose of Pramipexole Accord should be administered in two divided doses, starting at 0.088 mg of base (0.125 mg of salt) twice a day (0.176 mg of base/0.25 mg of salt daily). A maximum daily dose of 1.57 mg pramipexole base (2.25 mg of salt) should not be exceeded.



In patients with a creatinine clearance less than 20 ml/min, the daily dose of Pramipexole Accord should be administered in a single dose, starting at 0.088 mg of base (0.125 mg of salt) daily. A maximum daily dose of 1.1 mg pramipexole base (1.5 mg of salt) should not be exceeded.



If renal function declines during maintenance therapy the Pramipexole Accord daily dose should be reduced by the same percentage as the decline in creatinine clearance, i.e. if creatinine clearance declines by 30%, then the Pramipexole Accord daily dose should be reduced by 30%. The daily dose can be administered in two divided doses if creatinine clearance is between 20 and 50 ml/min and as a single daily dose if creatinine clearance is less than 20 ml/min.



Dosing in patients with hepatic impairment



Dose adjustment in patients with hepatic failure is probably not necessary, as approx. 90% of absorbed active substance is excreted through the kidneys. However, the potential influence of hepatic insufficiency on Pramipexole Accord pharmacokinetics has not been investigated.



Paediatric population



The safety and efficacy of Pramipexole Accord in children below 18 years has not been established. There is no relevant use of Pramipexole Accord in the paediatric population in Parkinson's disease.



Restless Legs Syndrome



The recommended starting dose of Pramipexole Accord is 0.088 mg of base (0.125 mg of salt) taken once daily 2-3 hours before bedtime. For patients requiring additional symptomatic relief, the dose may be increased every 4-7 days to a maximum of 0.54 mg of base (0.75 mg of salt) per day (as shown in the table below).

























Dose Schedule of Pramipexole Accord


  


Titration Step




Once Daily Evening Dose (mg of base)




Once Daily Evening Dose (mg of salt)




1




0.088




0.125




2*




0.18




0.25




3*




0.35




0.50




4*




0.54




0.75




* if needed


  


Patient's response should be evaluated after 3 months treatment and the need for treatment continuation should be reconsidered. If treatment is interrupted for more than a few days it should be re-initiated by dose titration carried out as above.



Treatment discontinuation



Since the daily dose for the treatment of Restless Legs Syndrome will not exceed 0.54 mg of base (0.75 mg of salt) Pramipexole Accord can be discontinued without tapering off. In a 26 week placebo controlled trial, rebound of RLS symptoms (worsening of symptom severity as compared to baseline) was observed in 10% of patients (14 out of 135) after abrupt discontinuation of treatment. This effect was found to be similar across all doses.



Dosing in patients with renal impairment



The elimination of pramipexole is dependent on renal function. Patients with a creatinine clearance above 20 ml/min require no reduction in daily dose.



The use of Pramipexole Accord has not been studied in haemodialysis patients, or in patients with severe renal impairment.



Dosing in patients with hepatic impairment



Dose adjustment in patients with hepatic failure is not required, as approx. 90% of absorbed active substance is excreted through the kidneys.



Paediatric population



Pramipexole Accord is not recommended for use in children and adolescents below 18 years due to a lack of data on safety and efficacy.



Tourette Disorder



Paediatric population



Pramipexole Accord is not recommended for use in children and adolescents below 18 years since the efficacy and safety has not been established in this population. Pramipexole Accord should not be used in children or adolescents with Tourette Disorder because of a negative benefit-risk balance for this disorder (see section 5.1).



Method of administration



The tablets should be taken orally, swallowed with water, and can be taken either with or without food.



4.3 Contraindications



Hypersensitivity to the active substance or to any of the excipients.



4.4 Special Warnings And Precautions For Use



When prescribing Pramipexole Accord in a patient with Parkinson's disease with renal impairment a reduced dose is suggested in line with section 4.2.



Hallucinations



Hallucinations are known as a side effect of treatment with dopamine agonists and levodopa. Patients should be informed that (mostly visual) hallucinations can occur.



Dyskinesia



In advanced Parkinson's disease, in combination treatment with levodopa, dyskinesia can occur during the initial titration of Pramipexole Accord. If they occur, the dose of levodopa should be decreased.



Sudden onset of sleep and somnolence



Pramipexole has been associated with somnolence and episodes of sudden sleep onset, particularly in patients with Parkinson's disease. Sudden onset of sleep during daily activities, in some cases without awareness or warning signs, has been reported uncommonly. Patients must be informed of this and advised to exercise caution while driving or operating machines during treatment with Pramipexole Accord. Patients who have experienced somnolence and/or an episode of sudden sleep onset must refrain from driving or operating machines. Furthermore a reduction of the dose or termination of therapy may be considered. Because of possible additive effects, caution should be advised when patients are taking other sedating medicinal products or alcohol in combination with pramipexole (see sections 4.5, 4.7 and section 4.8).



Impulse control disorders and compulsive behaviours



Pathological gambling, increased libido and hypersexuality have been reported in patients treated with dopamine agonists for Parkinson's disease, including Pramipexole Accord. Furthermore, patients and caregivers should be aware of the fact that other behavioural symptoms of impulse control disorders and compulsions such as binge eating and compulsive shopping can occur. Dose reduction/tapered discontinuation should be considered.



Patients with psychotic disorders



Patients with psychotic disorders should only be treated with dopamine agonists if the potential benefits outweigh the risks. Co-administration of antipsychotic medicinal products with pramipexole should be avoided (see section 4.5).



Ophthalmologic monitoring



Ophthalmologic monitoring is recommended at regular intervals or if vision abnormalities occur.



Severe cardiovascular disease



In case of severe cardiovascular disease, care should be taken. It is recommended to monitor blood pressure, especially at the beginning of treatment, due to the general risk of postural hypotension associated with dopaminergic therapy.



Neuroleptic malignant syndrome



Symptoms suggestive of neuroleptic malignant syndrome have been reported with abrupt withdrawal of dopaminergic therapy (see section 4.2).



Augmentation



Reports in the literature indicate that treatment of Restless Legs Syndrome with dopaminergic medicinal products can result in augmentation. Augmentation refers to the earlier onset of symptoms in the evening (or even the afternoon), increase in symptoms, and spread of symptoms to involve other extremities. Augmentation was specifically investigated in a controlled clinical trial over 26 weeks. Augmentation was observed in 11.8% of patients in the pramipexole group (N = 152) and 9.4% of patients in the placebo group (N = 149). Kaplan-Meier analysis of time to augmentation showed no significant difference between pramipexole and placebo groups.



4.5 Interaction With Other Medicinal Products And Other Forms Of Interaction



Plasma protein binding



Pramipexole is bound to plasma proteins to a very low (< 20%) extent, and little biotransformation is seen in man. Therefore, interactions with other medicinal products affecting plasma protein binding or elimination by biotransformation are unlikely. As anticholinergics are mainly eliminated by biotransformation, the potential for an interaction is limited, although an interaction with anticholinergics has not been investigated. There is no pharmacokinetic interaction with selegiline and levodopa.



Inhibitors/competitors of active renal elimination pathway



Cimetidine reduced the renal clearance of pramipexole by approximately 34%, presumably by inhibition of the cationic secretory transport system of the renal tubules. Therefore, medicinal products that are inhibitors of this active renal elimination pathway or are eliminated by this pathway, such as cimetidine, amantadine, mexiletine, zidovudine, cisplatin, quinine, and procainamide, may interact with pramipexole resulting in reduced clearance of pramipexole. Reduction of the pramipexole dose should be considered when these medicinal products are administered concomitantly with Pramipexole Accord.



Combination with levodopa



When Pramipexole Accord is given in combination with levodopa, it is recommended that the dose of levodopa is reduced and the dose of other anti-parkinsonian medicinal products is kept constant while increasing the dose of Pramipexole Accord.



Because of possible additive effects, caution should be advised when patients are taking other sedating medicinal products or alcohol in combination with pramipexole (see section 4.4, 4.7 and 4.8).



Antipsychotic medicinal products



Co-administration of antipsychotic medicinal products with pramipexole should be avoided (see section 4.4), e.g. if antagonistic effects can be expected.



4.6 Pregnancy And Lactation



Pregnancy



The effect on pregnancy and lactation has not been investigated in humans. Pramipexole was not teratogenic in rats and rabbits, but was embryotoxic in the rat at maternotoxic doses (see section 5.3). Pramipexole Accord should not be used during pregnancy unless clearly necessary, i.e. if the potential benefit justifies the potential risk to the foetus.



Breastfeeding



As pramipexole treatment inhibits secretion of prolactin in humans, inhibition of lactation is expected. The excretion of pramipexole into breast milk has not been studied in women. In rats, the concentration of active substance-related radioactivity was higher in breast milk than in plasma.



In the absence of human data, Pramipexole Accord should not be used during breast-feeding. However, if its use is unavoidable, breast-feeding should be discontinued.



Fertility



No studies on the effect on human fertility have been conducted. In animal studies, pramipexole affected oestrous cycles and reduced female fertility as expected for a dopamine agonist. However, these studies did not indicate direct or indirect harmful effects with respect to male fertility.



4.7 Effects On Ability To Drive And Use Machines



Pramipexole Accord has major influence on the ability to drive and use machines.



Hallucinations or somnolence can occur.



Patients being treated with Pramipexole Accord and presenting with somnolence and/or sudden sleep episodes must be informed to refrain from driving or engaging in activities where impaired alertness may put themselves or others at risk of serious injury or death (e.g. operating machines) until such recurrent episodes and somnolence have resolved (see also sections 4.4, 4.5 and 4.8).



4.8 Undesirable Effects



Expected adverse reactions



The following adverse reactions are expected under the use of Pramipexole Accord: abnormal dreams, amnesia, behavioural symptoms of impulse control disorders and compulsions such as binge eating, compulsive shopping, hypersexuality and pathological gambling; confusion, constipation, delusion, dizziness, dyskinesia, dyspnoea, fatigue, hallucinations, headache, hiccups, hyperkinesia, hyperphagia, hypotension, insomnia, libido disorders, nausea, paranoia, peripheral oedema, pneumonia, pruritus, rash and other hypersensitivity; restlessness, somnolence, sudden onset of sleep, syncope, visual impairment including diplopia, vision blurred and visual acuity reduced, vomiting, weight decrease including decreased appetite, weight increase.



Based on the analysis of pooled placebo-controlled trials, comprising a total of 1,923 patients on pramipexole and 1,354 patients on placebo, adverse drug reactions were frequently reported for both groups. 63% of patients on pramipexole and 52% of patients on placebo reported at least one adverse drug reaction.



Tables 1 and 2 display the frequency of adverse drug reactions from placebo-controlled clinical trials in Parkinson's disease and Restless Legs Syndrome. The adverse drug reactions reported in these tables are those events that occurred in 0.1% or more of patients treated with pramipexole and were reported significantly more often in patients taking pramipexole than placebo, or where the event was considered clinically relevant. The majority of adverse drug reactions were mild to moderate, they usually start early in therapy and most tended to disappear even as therapy was continued.



Within the system organ classes, adverse reactions are listed under headings of frequency (number of patients expected to experience the reaction), using the following categories: very common (



Parkinson's disease, most common adverse reactions



The most commonly (



Table 1: Parkinson's disease
























































System Organ Class




Adverse Drug Reaction




Infections and infestations


 


Uncommon




pneumonia




Psychiatric disorders


 


Common




abnormal dreams, behavioural symptoms of impulse control disorders and compulsions, confusion, hallucinations, insomnia




Uncommon




binge eating, compulsive shopping, delusion, hyperphagia, hypersexuality, libido disorder, paranoia, pathological gambling, restlessness




Nervous system disorders


 


Very common




dizziness, dyskinesia, somnolence




Common




headache




Uncommon




amnesia, hyperkinesia, sudden onset of sleep, syncope




Eye disorders


 


Common




visual impairment including diplopia, vision blurred and visual acuity reduced




Vascular disorders


 


Common




hypotension




Respiratory, thoracic, and mediastinal disorders


 


Uncommon




dyspnoea, hiccups




Gastrointestinal disorders


 


Very common




nausea




Common




constipation, vomiting




Skin and subcutaneous tissue disorders


 


Uncommon




hypersensitivity, pruritus, rash




General disorders and administration site conditions


 


Common




fatigue, peripheral oedema




Investigations


 


Common




weight decrease including decreased appetite




Uncommon




weight increase



Restless Legs Syndrome, most common adverse reactions



The most commonly (



Table 2: Restless Legs Syndrome






















































System Organ Class




Adverse Drug Reaction




Infections and infestations


 


Uncommon




pneumonia




Psychiatric disorders


 


Common




abnormal dreams, insomnia




Uncommon




behavioural symptoms of impulse control disorders and compulsions such as binge eating, compulsive shopping, hypersexuality, and pathological gambling; confusion, delusion, hallucinations, hyperphagia, libido disorder, paranoia, restlessness




Nervous system disorders


 


Common




dizziness, headache, somnolence




Uncommon




amnesia, dyskinesia, hyperkinesia, sudden onset of sleep, syncope




Eye disorders


 


Uncommon




visual impairment including diplopia, vision blurred and visual acuity reduced




Vascular disorders


 


Uncommon




hypotension




Respiratory, thoracic, and mediastinal disorders


 


Uncommon




dyspnoea, hiccups




Gastrointestinal disorders


 


Very common




nausea




Common




constipation, vomiting




Skin and subcutaneous tissue disorders


 


Uncommon




hypersensitivity, pruritus, rash




General disorders and administration site conditions


 


Common




fatigue




Uncommon




peripheral oedema




Investigations


 


Uncommon




weight decrease including decreased appetite, weight increase



Somnolence



Pramipexole is commonly associated with somnolence and has been associated uncommonly with excessive daytime somnolence and sudden sleep onset episodes (see also section 4.4).



Libido disorders



Pramipexole may uncommonly be associated with libido disorders (increased or decreased).



Impulse control disorders and compulsive behaviours



Patients treated with dopamine agonists for Parkinson's disease, including Pramipexole Accord, especially at high doses, have been reported as exhibiting signs of pathological gambling, increased libido and hypersexuality, generally reversible upon reduction of the dose or treatment discontinuation (see also section 4.4).



In a cross-sectional, retrospective screening and case-control study including 3,090 Parkinson's disease patients, 13.6% of all patients receiving dopaminergic or non-dopaminergic treatment had symptoms of an impulse control disorder during the past six months. Manifestations observed include pathological gambling, compulsive shopping, binge eating, and compulsive sexual behaviour (hypersexuality). Possible independent risk factors for impulse control disorders included dopaminergic treatments and higher doses of dopaminergic treatment, younger age (



4.9 Overdose



There is no clinical experience with massive overdose. The expected adverse reactions would be those related to the pharmacodynamic profile of a dopamine agonist, including nausea, vomiting, hyperkinesia, hallucinations, agitation and hypotension. There is no established antidote for overdose of a dopamine agonist. If signs of central nervous system stimulation are present, a neuroleptic agent may be indicated. Management of the overdose may require general supportive measures, along with gastric lavage, intravenous fluids, administration of activated charcoal and electrocardiogram monitoring.



5. Pharmacological Properties



5.1 Pharmacodynamic Properties



Pharmacotherapeutic group: anti-Parkinson drugs, dopamine agonists, ATC code: N04BC05.



Pramipexole is a dopamine agonist that binds with high selectivity and specificity to the D2 subfamily of dopamine receptors of which it has a preferential affinity to D3 receptors, and has full intrinsic activity.



Pramipexole alleviates parkinsonian motor deficits by stimulation of dopamine receptors in the striatum. Animal studies have shown that pramipexole inhibits dopamine synthesis, release, and turnover.



The mechanism of action of pramipexole as treatment for Restless Legs Syndrome is unknown. Neuropharmacological evidence suggests primary dopaminergic system involvement.



In human volunteers, a dose-dependent decrease in prolactin was observed. In a clinical trial with healthy volunteers, where pramipexole prolonged-release tablets were titrated faster (every 3 days) than recommended up to 3.15 mg pramipexole base (4.5 mg of salt) per day, an increase in blood pressure and heart rate was observed. Such effect was not observed in patient studies.



Clinical trials in Parkinson's disease



In patients pramipexole alleviates signs and symptoms of idiopathic Parkinson's disease. Placebo-controlled clinical trials included approximately 1,800 patients of Hoehn and Yahr stages I – V treated with pramipexole. Out of these, approximately 1,000 were in more advanced stages, received concomitant levodopa therapy, and suffered from motor complications.



In early and advanced Parkinson's disease, efficacy of pramipexole in controlled clinical trials was maintained for approximately six months. In open continuation trials lasting for more than three years there were no signs of decreasing efficacy.



In a controlled double blind clinical trial of 2 year duration, initial treatment with pramipexole significantly delayed the onset of motor complications, and reduced their occurrence compared to initial treatment with levodopa. This delay in motor complications with pramipexole should be balanced against a greater improvement in motor function with levodopa (as measured by the mean change in UPDRS-score). The overall incidence of hallucinations and somnolence was generally higher in the escalation phase with the pramipexole group. However, there was no significant difference during the maintenance phase. These points should be considered when initiating pramipexole treatment in patients with Parkinson's disease.



The European Medicines Agency has waived the obligation to submit the results of studies with Pramipexole Accord in all subsets of the paediatric population in Parkinson's Disease (see section 4.2 for information on paediatric use).



Clinical trials in Restless Legs Syndrome



The efficacy of pramipexole was evaluated in four placebo-controlled clinical trials in approximately 1,000 patients with moderate to very severe idiopathic Restless Legs Syndrome.



The mean change from baseline in the Restless Legs Syndrome Rating Scale (IRLS) and the Clinical Global Impression-Improvement (CGI-I) were the primary efficacy outcome measures. For both primary endpoints statistically significant differences have been observed for the pramipexole dose groups 0.25 mg, 0.5 mg and 0.75 mg pramipexole salt in comparison to placebo. After 12 weeks of treatment the baseline IRLS score improved from 23.5 to 14.1 points for placebo and from 23.4 to 9.4 points for pramipexole (doses combined). The adjusted mean difference was -4.3 points (CI 95% -6.4; -2.1 points, p-value <0.0001). CGI-I responder rates (improved, very much improved) were 51.2% and 72.0% for placebo and pramipexole, respectively (difference 20% CI 95%: 8.1%; 31.8%, p<0.0005). Efficacy was observed with 0.088 mg of base (0.125 mg of salt) per day after the first week of treatment.



In a placebo-controlled polysomnography study over 3 weeks Pramipexole Accord significantly reduced the number of periodic limb movements during time in bed.



Longer term efficacy was evaluated in a placebo-controlled clinical trial. After 26 weeks of treatment, there was an adjusted mean reduction in IRLS total score of 13.7 and 11.1 points in the pramipexole and placebo group, respectively, with a statistically significant (p = 0.008) mean treatment difference of -2.6. CGI-I responder rates (much improved, very much improved) were 50.3% (80/159) and 68.5% (111/162) for placebo and pramipexole, respectively (p = 0.001), corresponding to a number needed to treat (NNT) of 6 patients (95%CI: 3.5, 13.4).



The European Medicines Agency has deferred the obligation to submit the results of studies with Pramipexole Accord in one or more subsets of the paediatric population in Restless Legs Syndrome (see section 4.2 for information on paediatric use).



Clinical trial in Tourette Disorder



The efficacy of pramipexole (0.0625-0.5 mg/day) with paediatric patients aged 6-17 years with Tourette Disorder was evaluated in a 6-week, double-blind, randomised, placebo-controlled flexible dose study. A total of 63 patients were randomised (43 on pramipexole, 20 on placebo). The primary endpoint was change from baseline on the Total Tic Score (TTS) of the Yale Global Tic Severity Scale (YGTSS). No difference was observed for pramipexole as compared to placebo for either the primary endpoint or for any of the secondary efficacy endpoints including YGTSS total score, Patient Global Impression of Improvement (PGI-I), Clinical Global Impression of Improvement (CGI-I), or Clinical Global Impressions of Severity of Illness (CGI-S). Adverse events occurring in at least 5% of patients in the pramipexole group and more common in the pramipexole-treated patients than in patients on placebo were: headache (27.9%, placebo 25.0%), somnolence (7.0%, placebo 5.0%), nausea (18.6%, placebo 10.0%), vomiting (11.6%, placebo 0.0%), upper abdominal pain (7.0%, placebo 5.0%), orthostatic hypotension (9.3%, placebo 5.0%), myalgia (9.3%, placebo 5.0%), sleep disorder (7.0%, placebo 0.0%), dyspnoea (7.0%, placebo 0.0%) and upper respiratory tract infection (7.0%, placebo 5.0%). Other significant adverse events leading to discontinuation of study medication for patients receiving pramipexole were confusional state, speech disorder and aggravated condition (see section 4.2).



5.2 Pharmacokinetic Properties



Pramipexole is rapidly and completely absorbed following oral administration. The absolute bioavailability is greater than 90% and the maximum plasma concentrations occur between 1 and 3 hours. Concomitant administration with food did not reduce the extent of pramipexole absorption, but the rate of absorption was reduced. Pramipexole shows linear kinetics and a small inter-patient variation of plasma levels. In humans, the protein binding of pramipexole is very low (< 20%) and the volume of distribution is large (400 l). High brain tissue concentrations were observed in the rat (approx. 8-fold compared to plasma).



Pramipexole is metabolised in man only to a small extent.



Renal excretion of unchanged pramipexole is the major route of elimination. Approximately 90% of 14C-labelled dose is excreted through the kidneys while less than 2% is found in the faeces. The total clearance of pramipexole is approximately 500 ml/min and the renal clearance is approximately 400 ml/min. The elimination half-life (t½) varies from 8 hours in the young to 12 hours in the elderly.



5.3 Preclinical Safety Data



Repeated dose toxicity studies showed that pramipexole exerted functional effects, mainly involving the CNS and female reproductive system, and probably resulting from an exaggerated pharmacodynamic effect of pramipexole.



Decreases in diastolic and systolic pressure and heart rate were noted in the minipig, and a tendency to a hypotensive effect was discerned in the monkey.



The potential effects of pramipexole on reproductive function have been investigated in rats and rabbits. Pramipexole was not teratogenic in rats and rabbits but was embryotoxic in the rat at maternally toxic doses. Due to the selection of animal species and the limited parameters investigated, the adverse effects of pramipexole on pregnancy and male fertility have not been fully elucidated.



A delay in sexual development (i.e., preputial separation and vaginal opening) was observed in rats. The relevance for humans is unknown.



Pramipexole was not genotoxic. In a carcinogenicity study, male rats developed Leydig cell hyperplasia and adenomas, explained by the prolactin-inhibiting effect of pramipexole. This finding is not clinically relevant to man. The same study also showed that, at doses of 2 mg/kg (of salt) and higher, pramipexole was associated with retinal degeneration in albino rats. The latter finding was not observed in pigmented rats, nor in a 2-year albino mouse carcinogenicity study or in any other species investigated.



6. Pharmaceutical Particulars



6.1 List Of Excipients



Mannitol



Cellulose, microcrystalline



Maize starch



Silica, colloidal anhydrous



Povidone



Magnesium stearate



6.2 Incompatibilities



Not applicable.



6.3 Shelf Life



18 months



6.4 Special Precautions For Storage



Store below 30°C. Store in the original package in order to protect from light.



6.5 Nature And Contents Of Container



Pramipexole Accord 1.1mg tablets are packed in alu-alu (PVC) blisters.



Each blister strip contains 10 tablets.



Pack-sizes of 30 or 100 tablets



Not all pack sizes may be marketed.



6.6 Special Precautions For Disposal And Other Handling



Any unused product or waste material should be disposed of in accordance with local requirement.



7. Marketing Authorisation Holder



Accord Healthcare Limited



5th Floor Charles House



108/110 Finchley road



London NW3 5JJ



United Kingdom



8. Marketing Authorisation Number(S)



EMEA/H/C/002291/0000/009: x 30 tablets



EMEA/H/C/002291/0000/010: x 100 tablets



9. Date Of First Authorisation/Renewal Of The Authorisation



30-Sep-2011



10. Date Of Revision Of The Text



Detailed information on this product is available on the website of the European Medicines Agency http://www.ema.europa.eu.




Wednesday, 30 May 2012

Virgan Eye Gel





1. Name Of The Medicinal Product







 
 

 


VIRGAN eye gel.


2. Qualitative And Quantitative Composition



Active Ingredient.



Ganciclovir 0.15%



3. Pharmaceutical Form



Eye gel.



4. Clinical Particulars



4.1 Therapeutic Indications



Treatment of acute herpetic keratitis (dendritic and geographic ulcers).



4.2 Posology And Method Of Administration



Instil one drop of gel in the inferior conjunctival sac of the eye to be treated, 5 times a day until complete corneal re-epithelialisation. Then 3 instillations a day for 7 days after healing. The treatment does not usually exceed 21 days.



Use in the elderly:



The dosage in the elderly is the same as in adults (see above). There is no need to adjust the dosage in the elderly as in clinical trials patients up to the age of 85 years have been treated and no specific health concerns were observed.



Use in children:



VIRGAN eye gel is not recommended for use in children.



Only limited clinical trial data are available. (7 children, range 2-14 years).



4.3 Contraindications



Hypersensitivity to ganciclovir or acyclovir or to any other ingredients of the product.



4.4 Special Warnings And Precautions For Use



The following special warnings and precautions for use should be borne in mind, although systemic effects after ocular instillation are very unlikely. In preclinical testing ganciclovir given systemically caused aspermatogenesis, mutagenicity, teratogenicity, carcinogenicity and suppression of female fertility. These effects in animal studies have been observed at plasma concentrations far exceeding those being seen in humans after therapeutic use of Virgan Eye Gel (see also 5.3). However, ganciclovir should be considered a potential carcinogen and teratogen in humans.



4.5 Interaction With Other Medicinal Products And Other Forms Of Interaction



In case of any additional local ocular treatment there should be an application interval of at least 5 minutes between the two medications. VIRGAN Eye Gel should be the last medication instilled.



Although the quantities of ganciclovir passing into the general circulation after ophthalmic use are small, the risk of drug interactions cannot be ruled out. Interactions with ganciclovir administered systemically have been observed.



Binding of ganciclovir to plasma proteins is only about 1-2% and drug interactions involving binding site displacement are not anticipated.



It is possible that drugs which inhibit replication of rapidly dividing cell populations such as bone marrow, spermatogonia and germinal layers of skin and gastrointestinal mucosa might have combined additive toxic effects when used concomitantly with, before, or after ganciclovir. Because of the possibility of additive toxicity with co-administration of drugs such as dapsone, pentamidine, flucystosine, vincristine, vinblastine, adriamycin, amphotericin B, trimethoprim/sulpha combinations or other nucleoside analogues, combination with ganciclovir therapy should be used only if the potential benefits outweigh the risks.



Since both zidovudine and ganciclovir can result in neutropenia, it is recommended that these two drugs should not be given concomitantly during induction treatment with ganciclovir. Maintenance ganciclovir treatment plus zidovudine at the recommended dose resulted in severe neutropenia in most patients studied to date.



Generalised seizures have been reported in patients taking ganciclovir and imipenem-cilastatin concomitantly.



It is also possible that probenecid, as well as other drugs which inhibit renal tubular secretion or resorption, may reduce renal clearance of ganciclovir and could increase the plasma half-life of ganciclovir.



4.6 Pregnancy And Lactation



Teratogenicity has been observed in animal studies with systemic ganciclovir. There is no experience regarding the safety of VIRGAN eye gel in human pregnancy or lactation. Administration during pregnancy and lactation is therefore not recommended, except for compelling reasons.



4.7 Effects On Ability To Drive And Use Machines



Patients should refrain from driving a vehicle or operating machines on the occurrence of any visual disturbance or other visual symptomatology.



4.8 Undesirable Effects



In some cases, adverse events which did not result in a treatment interruption were observed in relation to the use of VIRGAN eye gel; burning sensations or brief tingling sensations, superficial punctate keratitis, visual disturbance on application.



4.9 Overdose



There is practically no risk of adverse events due to accidental oral ingestion since a tube of 5g contains 7.5mg ganciclovir compared to the daily adult i.v dose of 500-1000mg.



In the unlikely event of overdose, dialysis and hydration may be of benefit in reducing drug plasma levels.



Toxic manifestations seen in animals given very high single intravenous doses of ganciclovir (500mg/kg) included emesis, hypersalivation, anorexia, bloody diarrhoea, inactivity, cytopenia, abnormal liver function tests and BUN, testicular atrophy and death.



5. Pharmacological Properties



5.1 Pharmacodynamic Properties



VIRGAN®is a formulation of 0.15% ganciclovir in a transparent aqueous gel with a hydrophilic polymer base.



Ganciclovir, 9-(1,3-dihydroxy-2-propoxymethyl)guanine or DHPG, is a broad-spectrum virustatic agent which inhibits the replication of viruses, including viruses of the herpes group, both in vivo and in vitro: herpes simplex types 1 and 2 (HSV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes zoster (HZV).



The mean effective dose (ED50) in vitro of ganciclovir on ocular clinical isolates of the herpes simplex virus is on average 0.23μg/ml (0.06 - 0.50). Ganciclovir inhibits in vitro the replication of various adenovirus serotypes. The ED50 is 1.8 to 4.0μg/ml for Ad 8 and Ad 19, those most frequently seen in ophthalmology.



Herpetic viruses induce one or more cellular kinases in the host cells, which phosphorylise the ganciclovir into its triphosphate derivative. This phosphorylation is carried out mainly in infected cells, as the concentrations of ganciclovir-triphosphate in non-infected cells are 10 times lower.



Ganciclovir-triphosphate works as an antiviral agent by inhibiting the synthesis of viral DNA in two ways: competitive inhibition of viral DNA-polymerases and direct incorporation into viral DNA which has the effect of stopping its elongation.



5.2 Pharmacokinetic Properties



Studies of ocular pharmacokinetics in rabbits have shown a rapid and relevant penetration of ganciclovir into the cornea and the anterior segment of the eye, allowing concentrations higher than the effective antiviral concentrations over several hours. In fact, after instillation of one drop of ganciclovir gel, the concentrations (Cmax) of ganciclovir measured in the cornea (17μg/g), the conjunctiva (160μg/g), the aqueous humour (1μg/g) and the iris/ciliary body (4μg/g), are higher than the inhibitory concentrations for herpes simplex viruses 1 and 2 (<0.5μg/ml) over more than 4 hours.



The repeated instillation 4 times a day for 12 days in rabbits with herpetic keratitis does not result in an accumulation of ganciclovir in the plasma.



In man, after daily ocular instillations repeated 5 times a day for 11 to 15



days in the course of treatment of superficial herpetic keratitis, plasma levels determined by means of a precise analytical method (quantification



limit: 0.005μg/ml) are very low: on average 0.013μg/ml (0 - 0.037) which is



640 times lower than levels following a one hour i.v infusion of 5mg/kg



(Cmax=8.0μg/ml). The oral bioavailability of ganciclovir is approximately



6% when taken with food. Ganciclovir has a half life of 2.9 hours, the



systemic clearance is 3.64ml/min/kg and the major route of excretion of



ganciclovir is via glomerular filtration of unchanged drug.



5.3 Preclinical Safety Data



Animal data indicate that a side-effect of systemic ganciclovir is inhibition of spermatogenesis which is reversible at lower doses and irreversible at higher doses. Animal data have also indicated that permanent suppression of fertility in women may occur.



Ganciclovir had no effect on developing mouse foetuses at daily intravenous doses of 36mg/kg, but caused maternal/foetal toxicity and embryo death at daily doses of 108mg/kg. In rabbits, ganciclovir had no effect on developing foetuses at daily intravenous doses of 6mg/kg, but caused foetal growth retardation, embryo death, teratogenicity and/or maternal toxicity at daily doses of 20 or 60mg/kg.



Ganciclovir did not cause point mutations in bacterial or yeast cells or dominant lethality in mice, but caused point mutations and chromosomal damage in mammalian cells in vitro and in vivo. Ganciclovir was positive in these tests at thousands of times the concentration in plasma of patients undergoing therapy with VIRGAN eye gel.



Ganciclovir was carcinogenic in the mouse after daily oral doses of 20 and 1000mg/kg/day. No carcinogenic effect occurred at the dose of 1mg/kg/day. Tumour incidence was slightly increased at plasma levels of ganciclovir approximately 50 times human levels following VIRGAN eye gel treatment.



6. Pharmaceutical Particulars



6.1 List Of Excipients



Benzalkonium chloride, Carbomer 974P, Sorbitol, Sodium hydroxide



Purified water



6.2 Incompatibilities



None known to date.



6.3 Shelf Life



In the unopened container: 3 years.



In the opened container: 4 weeks.



6.4 Special Precautions For Storage



Do not store above 25°C.



6.5 Nature And Contents Of Container



5g tube (polyethylene-aluminium) with dropper nozzle (polyethylene) and screw cap (polyethylene) fitted with a detachable plastic base. This base allows the tube to be placed vertically, with the dropper nozzle pointing downwards, thus avoiding an accumulation of air around the opening, which would inhibit the correct formation of drops.



6.6 Special Precautions For Disposal And Other Handling



The package remains sterile until the original closure is broken. Do not use



VIRGAN eye gel for more than 28 days after first opening.



Administrative Data


7. Marketing Authorisation Holder



Chauvin Pharmaceuticals Ltd



Ashton Road



Harold Hill



Romford



Essex



RM3 8SL



United Kingdom



8. Marketing Authorisation Number(S)



PL 00033/0158



9. Date Of First Authorisation/Renewal Of The Authorisation



21 July 2000



10. Date Of Revision Of The Text



February 2002




Gablofen


Generic Name: baclofen (Intrathecal route)

BAK-loe-fen

Intrathecal route(Solution)

Abrupt discontinuation of intrathecal baclofen, regardless of the cause, has resulted in sequelae that include high fever, altered mental status, exaggerated rebound spasticity, and muscle rigidity, that in rare cases has advanced to rhabdomyolysis, multiple organ-system failure and death. Careful attention to programming and monitoring of the infusion system, refill scheduling and procedures, and pump alarms is necessary to avoid abrupt discontinuation of the drug. Educate patients and caregivers about the early symptoms of baclofen withdrawal .



Commonly used brand name(s)

In the U.S.


  • Gablofen

  • Lioresal

Available Dosage Forms:


  • Solution

  • Kit

Therapeutic Class: Skeletal Muscle Relaxant, Centrally Acting


Chemical Class: Gamma Aminobutyric Acid (class)


Uses For Gablofen


Intrathecal baclofen is used to help relax certain muscles in your body. It relieves the spasms, cramping, and tightness of muscles caused by medical problems such as multiple sclerosis, cerebral palsy, or certain injuries to the spine. Intrathecal baclofen does not cure these problems, but it may allow other treatment, such as physical therapy, to be more helpful in improving your condition.


Intrathecal baclofen acts on the central nervous system (CNS) to produce its muscle relaxant effects. Its actions on the CNS may also cause some of the medicine's side effects.


This medicine is delivered by a drug pump directly into the spinal fluid of your back. A doctor will surgically place the pump and monitor the dose of the medication that is delivered by the pump. The dose of intrathecal baclofen will be different for different patients and will depend on the type of muscle tightness that you have.


Intrathecal baclofen is given only by or under the direct supervision of a doctor.


Before Using Gablofen


In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:


Allergies


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Pediatric


This medicine has been tested in children 4 years of age and older. Effective doses have not been shown to cause different side effects or problems in children than it does in adults. However, this medicine may not be safe for children younger than 4 years of age.


Geriatric


Side effects such as hallucinations, confusion or mental depression, other mood or mental changes, and severe drowsiness may be especially likely to occur in elderly patients, who may be more sensitive than younger adults to the effects of intrathecal baclofen.


Pregnancy








Pregnancy CategoryExplanation
All TrimestersCAnimal studies have shown an adverse effect and there are no adequate studies in pregnant women OR no animal studies have been conducted and there are no adequate studies in pregnant women.

Breast Feeding


Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.


Interactions with Medicines


Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.


Interactions with Food/Tobacco/Alcohol


Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.


Other Medical Problems


The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:


  • Breathing difficulties or

  • Stroke or other brain disease—Baclofen may make these conditions worse

  • Communication difficulties or

  • Spinal cord injuries, at or above T–6 or

  • Withdrawal symptoms, history of—These conditions may increase your risk for side effects of baclofen

  • Epilepsy or

  • Kidney disease or

  • Mental or emotional problems or

  • Spinal lesions—The chance of side effects may be increased

  • Parkinson's disease—Baclofen may make this condition worse

Proper Use of baclofen

This section provides information on the proper use of a number of products that contain baclofen. It may not be specific to Gablofen. Please read with care.


Dosing


The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.


The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.


Precautions While Using Gablofen


Your doctor should check your progress at regular visits, especially during the first few weeks of treatment with this medicine. During this time, the amount of medicine you are using may have to be changed often to meet your individual needs.


Make sure to keep all appointments to refill the pump. If the pump is not refilled on time, you may experience return of your muscle tightness and early withdrawal symptoms which might include:


  • itching of the skin

  • decreased blood pressure
    • blurred vision

    • confusion

    • dizziness, faintness, or lightheadedness when getting up from a lying or sitting position suddenly

    • sweating

    • unusual tiredness or weakness


  • burning, crawling, itching, numbness, prickling, "pins and needles" , or tingling feelings

  • seizures

Intrathecal baclofen will add to the effects of alcohol and other CNS depressants (medicines that may make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds; sedatives, tranquilizers, or sleeping medicine; prescription pain medicine or narcotics; barbiturates; medicine for seizures; other muscle relaxants; and anesthetics, including some dental anesthetics. Check with your doctor before taking any of the above while you are using intrathecal baclofen.


Intrathecal baclofen may cause dizziness, drowsiness, false sense of well-being, lightheadedness, vision problems, or clumsiness or unsteadiness in some people. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert, well-coordinated, and able to see well.


Intrathecal baclofen may cause dryness of the mouth. For temporary relief, use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute. However, if dry mouth continues for more than 2 weeks, check with your medical doctor or dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.


Dizziness, lightheadedness, or fainting may occur when you get up suddenly from a lying or sitting position. Getting up slowly may help lessen this problem.


Gablofen Side Effects


Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.


Check with your doctor as soon as possible if any of the following side effects occur:


More common
  • Convulsions (seizures)

Less common or rare
  • Blurred vision or double vision

  • fainting

  • mental depression

  • muscle weakness

  • ringing or buzzing in ears

  • seeing, hearing, or feeling things that are not there

  • shortness of breath or troubled breathing

Symptoms of overdose
  • Convulsions (seizures)

  • dizziness, drowsiness, or lightheadedness

  • increased watering of the mouth

  • mental confusion

  • muscle weakness

  • nausea and/or vomiting

  • shortness of breath or troubled breathing

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:


More common
  • Constipation

  • difficult urination

  • dizziness

  • headache

  • nausea and/or vomiting

  • numbness or tingling in hands or feet

  • sleepiness

Less common
  • Clumsiness, unsteadiness, trembling, or other problems with muscle control

  • diarrhea

  • difficulty sleeping

  • dizziness or lightheadedness, especially when getting up from a lying or sitting position

  • dry mouth

  • frequent urge to urinate

  • irritation of the skin at the site where the pump is located

  • itching of the skin

  • sexual problems

  • slurred speech or other speech problems

  • swelling of ankles, feet, or lower legs

  • trembling or shaking

After you stop using this medicine, it may still produce some side effects that need attention. During this period of time, check with your doctor immediately if you notice the following side effects:


  • Convulsions (seizures)

  • facial flushing, headache, increased sweating, or slow heartbeat

  • increased muscle spasms

  • seeing, hearing, or feeling things that are not there

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.


Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

See also: Gablofen side effects (in more detail)



The information contained in the Thomson Reuters Micromedex products as delivered by Drugs.com is intended as an educational aid only. It is not intended as medical advice for individual conditions or treatment. It is not a substitute for a medical exam, nor does it replace the need for services provided by medical professionals. Talk to your doctor, nurse or pharmacist before taking any prescription or over the counter drugs (including any herbal medicines or supplements) or following any treatment or regimen. Only your doctor, nurse, or pharmacist can provide you with advice on what is safe and effective for you.


The use of the Thomson Reuters Healthcare products is at your sole risk. These products are provided "AS IS" and "as available" for use, without warranties of any kind, either express or implied. Thomson Reuters Healthcare and Drugs.com make no representation or warranty as to the accuracy, reliability, timeliness, usefulness or completeness of any of the information contained in the products. Additionally, THOMSON REUTERS HEALTHCARE MAKES NO REPRESENTATION OR WARRANTIES AS TO THE OPINIONS OR OTHER SERVICE OR DATA YOU MAY ACCESS, DOWNLOAD OR USE AS A RESULT OF USE OF THE THOMSON REUTERS HEALTHCARE PRODUCTS. ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE OR USE ARE HEREBY EXCLUDED. Thomson Reuters Healthcare does not assume any responsibility or risk for your use of the Thomson Reuters Healthcare products.


More Gablofen resources


  • Gablofen Side Effects (in more detail)
  • Gablofen Use in Pregnancy & Breastfeeding
  • Gablofen Drug Interactions
  • Gablofen Support Group
  • 0 Reviews for Gablofen - Add your own review/rating


  • Gablofen Consumer Overview

  • Gablofen Prescribing Information (FDA)

  • Gablofen MedFacts Consumer Leaflet (Wolters Kluwer)

  • Baclofen Prescribing Information (FDA)

  • Baclofen Professional Patient Advice (Wolters Kluwer)

  • Baclofen Monograph (AHFS DI)

  • Lioresal Prescribing Information (FDA)

  • Lioresal Intrathecal Prescribing Information (FDA)



Compare Gablofen with other medications


  • Cerebral Spasticity
  • Spasticity

Saturday, 26 May 2012

Cecon


Generic Name: ascorbic acid (vitamin C) (as KORE bik AS id)

Brand Names: Acerola, Ascorbic Acid Quick Melts, C-Time, C/Rose Hips, Cecon, Cemill 1000, Cemill 500, Ester-C, N Ice with Vitamin C, Sunkist Vitamin C, Vicks Vitamin C Drops, Vitamin C, Vitamin C TR, Vitamin C with Rose Hips


What is ascorbic acid?

Ascorbic acid (vitamin C) occurs naturally in foods such as citrus fruit, tomatoes, potatoes, and leafy vegetables. Ascorbic acid is important for bones and connective tissues, muscles, and blood vessels. Vitamin C also helps the body absorb iron, which is needed for red blood cell production.


Ascorbic acid is used to treat and prevent vitamin C deficiency.


Ascorbic acid may also be used for other purposes not listed in this medication guide.


What is the most important information I should know about ascorbic acid?


You should not use this medication if you have ever had an allergic reaction to ascorbic acid.

Ask a doctor or pharmacist about using ascorbic acid if you have kidney disease or a history of kidney stones, liver disease (especially cirrhosis), or an enzyme deficiency called glucose-6-phosphate dehydrogenase deficiency (G6PD).


It is not known whether ascorbic acid is harmful to an unborn baby or a nursing baby. Some vitamins and minerals are needed during pregnancy or for breast milk production, but some may be harmful if taken in large doses. Do not take ascorbic acid without telling your doctor if you are pregnant or breast-feeding.

Ascorbic acid can be harmful to the kidneys, and this effect is increased when ascorbic acid is used together with other medicines that can harm the kidneys. Before taking ascorbic acid, tell your doctor if you are receiving chemotherapy, or using medicines to treat a bowel disorder, medication to prevent organ transplant rejection, antiviral medications, pain or arthritis medicines, or any injected antibiotics. You may need dose adjustments or special tests when taking any of these medications together with ascorbic acid.


Before taking ascorbic acid, tell your doctor about all other medications you take.


Stop using ascorbic acid and call your doctor at once if you have severe pain in your lower back or side, blood in your urine, pain when you urinate, severe or ongoing diarrhea, or feel like you might pass out.

What should I discuss with my healthcare provider before taking ascorbic acid?


You should not use this medication if you have ever had an allergic reaction to ascorbic acid.

Ask a doctor or pharmacist about using ascorbic acid if you have:


  • kidney disease or a history of kidney stones;

  • liver disease (especially cirrhosis); or


  • an enzyme deficiency called glucose-6-phosphate dehydrogenase deficiency (G6PD).




It is not known whether ascorbic acid is harmful to an unborn baby. Some vitamins and minerals can harm an unborn baby if taken in large doses. You may need to use a prenatal vitamin specially formulated for pregnant women. Do not take ascorbic acid without telling your doctor if you are pregnant. Ascorbic acid can pass into breast milk, but it is not known whether it would be harmful to a nursing baby. Some vitamins and minerals are needed for breast milk production, but some may harm a nursing baby. Do not take ascorbic acid without telling your doctor if you are breast-feeding a baby.

How should I take ascorbic acid?


Use this medication exactly as directed on the label, or as prescribed by your doctor. Do not use it in larger amounts or for longer than recommended.


The recommended dietary allowance of ascorbic acid increases with age, and whether you are pregnant or breast-feeding. Follow your doctor's instructions. You may also consult the National Academy of Sciences "Dietary Reference Intake" or the U.S. Department of Agriculture's "Dietary Reference Intake" (formerly "Recommended Daily Allowances" or RDA) listings for more information.


Take the ascorbic acid regular tablet or capsule with a full glass (8 ounces) of water.

The ascorbic acid chewable tablet must be chewed before swallowing. Ascorbic acid gum may be chewed over a long period and then spit out and thrown away.


Remove the disintegrating tablet from the package using dry hands, and place the tablet in your mouth. It will begin to dissolve right away. Do not swallow the tablet whole. Allow it to dissolve in your mouth without chewing. Swallow several times as the tablet dissolves.


Measure liquid medicine with a special dose-measuring spoon or cup, not a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.


Dissolve the powder form of ascorbic acid in a small amount of water or other liquid. Follow the directions on the package label about what types of liquid you may use. Stir the mixture and drink all of it right away. To make sure you get the entire dose, add a little more water to the same glass, swirl gently and drink right away.


Store ascorbic acid at room temperature away from moisture and heat.

What happens if I miss a dose?


Take the missed dose as soon as you remember. If it is almost time for your next dose, wait until then to take the medicine and skip the missed dose. Do not take extra medicine to make up the missed dose.


What happens if I overdose?


Seek emergency medical attention if you think you have used too much of this medicine.

An overdose of ascorbic acid is not likely to cause life-threatening symptoms.


What should I avoid while taking ascorbic acid?


Follow your doctor's instructions about any restrictions on food, beverages, or activity.


Smoking can make ascorbic acid less effective.

Ascorbic acid side effects


Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat. Stop using ascorbic acid and call your doctor at once if you have a serious side effect such as:

  • severe pain in your lower back or side;




  • blood in your urine;




  • pain when you urinate;




  • severe or ongoing diarrhea; or




  • feeling like you might pass out.



Less serious side effects may include:



  • heartburn, stomach cramps;




  • nausea, vomiting, diarrhea;




  • headache, dizziness;




  • flushing (warmth, redness, or tingling under your skin);



This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


What other drugs will affect ascorbic acid?


Ascorbic acid can be harmful to the kidneys, and this effect is increased when ascorbic acid is used together with other medicines that can harm the kidneys. Before taking ascorbic acid, tell your doctor if you are receiving chemotherapy, or using medicines to treat a bowel disorder, medication to prevent organ transplant rejection, antiviral medications, pain or arthritis medicines, or any injected antibiotics.


You may need dose adjustments or special tests when taking any of these medications together with ascorbic acid.


The following drugs can interact with ascorbic acid. Tell your doctor if you are using any of these:



  • aspirin or acetaminophen (Tylenol);




  • fluphenazine (Permitil);




  • indinavir (Crixivan);




  • levodopa (Atamet, Larodopa, Parcopa, Sinemet);




  • nicotine patches (Nicoderm, Habitrol, Commit);




  • antacids that contain aluminum (such as Amphojel, Maalox, Mylanta, Rulox, and others);




  • an antibiotic such as demeclocycline (Declomycin), doxycycline (Adoxa, Doryx, Oracea, Vibramycin), minocycline (Dynacin, Minocin, Solodyn, Vectrin), or tetracycline (Brodspec, Panmycin, Sumycin, Tetracap); or




  • a barbiturate such as butabarbital (Butisol), secobarbital (Seconal), pentobarbital (Nembutal), or phenobarbital (Solfoton);




  • birth control pills or hormone replacement therapy, including Premarin, Estratest, Vivelle, Climara, Estring, Estrace, and others; or




  • a blood thinner such as warfarin (Coumadin).



This list is not complete and there may be other drugs that can interact with ascorbic acid. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.



More Cecon resources


  • Cecon Side Effects (in more detail)
  • Cecon Use in Pregnancy & Breastfeeding
  • Cecon Drug Interactions
  • Cecon Support Group
  • 0 Reviews for Cecon - Add your own review/rating


  • Cecon Advanced Consumer (Micromedex) - Includes Dosage Information

  • Cecon Solution MedFacts Consumer Leaflet (Wolters Kluwer)

  • Ascorbic Acid Monograph (AHFS DI)

  • Ascorbic Acid MedFacts Consumer Leaflet (Wolters Kluwer)

  • Acerola Natural MedFacts for Professionals (Wolters Kluwer)

  • Acerola Natural MedFacts for Consumers (Wolters Kluwer)

  • Cenolate Injection MedFacts Consumer Leaflet (Wolters Kluwer)

  • Cevi-Bid Controlled-Release Capsules MedFacts Consumer Leaflet (Wolters Kluwer)



Compare Cecon with other medications


  • Dietary Supplementation
  • Scurvy
  • Urinary Acidification


Where can I get more information?


  • Your doctor, pharmacist, or health care provider may have more information about ascorbic acid.

See also: Cecon side effects (in more detail)


Wednesday, 23 May 2012

Zithromax




Generic Name: azithromycin

Dosage Form: tablets and oral suspension
Zithromax®

(azithromycin tablets)

and

(azithromycin for oral suspension)

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Zithromax® (azithromycin) and other antibacterial drugs, Zithromax (azithromycin) should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria.



Zithromax Description


Zithromax (azithromycin tablets and azithromycin for oral suspension) contain the active ingredient azithromycin, an azalide, a subclass of macrolide antibiotics, for oral administration. Azithromycin has the chemical name (2R,3S,4R,5R,8R,10R,11R,12S,13S,14R) - 13 - [(2,6 - dideoxy - 3 - C - methyl - 3 - O - methyl - α - L - ribo - hexopyranosyl)oxy] - 2 - ethyl - 3,4,10 - trihydroxy - 3,5,6,8,10,12,14 - heptamethyl - 11 - [[3,4,6 - trideoxy - 3 - (dimethylamino) - β - D - xylo - hexopyranosyl]oxy] - 1 - oxa - 6 - azacyclopentadecan - 15 - one. Azithromycin is derived from erythromycin; however, it differs chemically from erythromycin in that a methyl-substituted nitrogen atom is incorporated into the lactone ring. Its molecular formula is C38H72N2O12, and its molecular weight is 749.0. Azithromycin has the following structural formula:



Azithromycin, as the dihydrate, is a white crystalline powder with a molecular formula of C38H72N2O12•2H2O and a molecular weight of 785.0.


Zithromax tablets contain azithromycin dihydrate equivalent to 600 mg azithromycin. The tablets are supplied as white, modified oval-shaped, film-coated tablets. They also contain the following inactive ingredients: dibasic calcium phosphate anhydrous, pregelatinized starch, sodium croscarmellose, magnesium stearate, sodium lauryl sulfate and an aqueous film coat consisting of hypromellose, titanium dioxide, lactose and triacetin.


Zithromax for oral suspension is supplied in a single dose packet containing azithromycin dihydrate equivalent to 1 g azithromycin. It also contains the following inactive ingredients: colloidal silicon dioxide, sodium phosphate tribasic, anhydrous; spray dried artificial banana flavor, spray dried artificial cherry flavor, and sucrose.



Zithromax - Clinical Pharmacology



Pharmacokinetics


Following oral administration, azithromycin is rapidly absorbed and widely distributed throughout the body. Rapid distribution of azithromycin into tissues and high concentration within cells result in significantly higher azithromycin concentrations in tissues than in plasma or serum. The 1 g single dose packet is bioequivalent to four 250 mg azithromycin capsules.


The pharmacokinetic parameters of azithromycin in plasma after dosing as per labeled recommendations in healthy young adults and asymptomatic HIV-seropositive adults (age 18–40 years old) are portrayed in the following chart:







































































































MEAN (CV%) PK PARAMETER



DOSE/DOSAGE FORM

(serum, except as indicated)



Subjects



Day No.


Cmax

(µg/mL)


Tmax

(hr)


C24

(µg/mL)


AUC

(µg∙hr/mL)




(hr)
Urinary

Excretion

(% of dose)

*

AUC0–24;


0–last.

500 mg/250 mg capsule12Day 10.412.50.052.6*4.5
  and 250 mg on Days 2–512Day 50.243.20.052.1*6.5
1200 mg/600 mg tablets12Day 10.662.50.0746.840
%CV    (62%)(79%)(49%)(64%)(33%)  
600 mg tablet/day710.332.00.0392.4*    
%CV25%(50%)(36%)(19%)
7220.552.10.145.8*84.5-
%CV(18%)(52%)(26%)(25%)-
600 mg tablet/day (leukocytes)72225210.91464763*82.8-
%CV(49%)(28%)(33%)(42%)--

In these studies (500 mg Day 1, 250 mg Days 2–5), there was no significant difference in the disposition of azithromycin between male and female subjects. Plasma concentrations of azithromycin following single 500 mg oral and I.V. doses declined in a polyphasic pattern resulting in an average terminal half-life of 68 hours. With a regimen of 500 mg on Day 1 and 250 mg/day on Days 2–5, Cmin and Cmax remained essentially unchanged from Day 2 through Day 5 of therapy. However, without a loading dose, azithromycin Cmin levels required 5 to 7 days to reach steady-state.


In asymptomatic HIV-seropositive adult subjects receiving 600-mg Zithromax tablets once daily for 22 days, steady state azithromycin serum levels were achieved by Day 15 of dosing.


When azithromycin capsules were administered with food, the rate of absorption (Cmax) of azithromycin was reduced by 52% and the extent of absorption (AUC) by 43%.


When the oral suspension of azithromycin was administered with food, the Cmax increased by 46% and the AUC by 14%.


The absolute bioavailability of two 600 mg tablets was 34% (CV=56%). Administration of two 600 mg tablets with food increased Cmax by 31% (CV=43%) while the extent of absorption (AUC) was unchanged (mean ratio of AUCs=1.00; CV=55%).


The AUC of azithromycin in 250 mg capsules was unaffected by coadministration of an antacid containing aluminum and magnesium hydroxide with Zithromax (azithromycin); however, the Cmax was reduced by 24%. Administration of cimetidine (800 mg) two hours prior to azithromycin had no effect on azithromycin absorption.


When studied in healthy elderly subjects from age 65 to 85 years, the pharmacokinetic parameters of azithromycin (500 mg Day 1, 250 mg Days 2–5) in elderly men were similar to those in young adults; however, in elderly women, although higher peak concentrations (increased by 30 to 50%) were observed, no significant accumulation occurred.


The high values in adults for apparent steady-state volume of distribution (31.1 L/kg) and plasma clearance (630 mL/min) suggest that the prolonged half-life is due to extensive uptake and subsequent release of drug from tissues. Selected tissue (or fluid) concentration and tissue (or fluid) to plasma/serum concentration ratios are shown in the following table:












































AZITHROMYCIN CONCENTRATIONS FOLLOWING TWO 250 mg (500 mg) CAPSULES IN ADULTS
TISSUE OR

FLUID
TIME AFTER DOSE (h)TISSUE OR FLUID

CONCENTRATION

(µg/g or µg/mL)*
CORRESPONDING

PLASMA OR SERUM

LEVEL (µg/mL)
TISSUE (FLUID)

PLASMA (SERUM)

RATIO*

*

High tissue concentrations should not be interpreted to be quantitatively related to clinical efficacy. The antimicrobial activity of azithromycin is pH related. Azithromycin is concentrated in cell lysosomes which have a low intraorganelle pH, at which the drug's activity is reduced. However, the extensive distribution of drug to tissues may be relevant to clinical activity.


Sample was obtained 2–4 hours after the first dose


Sample was obtained 10–12 hours after the first dose.

§

Dosing regimen of 2 doses of 250 mg each, separated by 12 hours.


Sample was obtained 19 hours after a single 500 mg dose.

SKIN72–960.40.01235
LUNG72–964.00.012>100
SPUTUM2–41.00.642
SPUTUM10–122.90.130
TONSIL§9–184.50.03>100
TONSIL§1800.90.006>100
CERVIX192.80.0470

The extensive tissue distribution was confirmed by examination of additional tissues and fluids (bone, ejaculum, prostate, ovary, uterus, salpinx, stomach, liver, and gallbladder). As there are no data from adequate and well-controlled studies of azithromycin treatment of infections in these additional body sites, the clinical significance of these tissue concentration data is unknown.


Following a regimen of 500 mg on the first day and 250 mg daily for 4 days, only very low concentrations were noted in cerebrospinal fluid (less than 0.01 µg/mL) in the presence of non-inflamed meninges.


Following oral administration of a single 1200 mg dose (two 600 mg tablets), the mean maximum concentration in peripheral leukocytes was 140 µg/mL. Concentrations remained above 32 µg/mL for approximately 60 hr. The mean half-lives for 6 males and 6 females were 34 hr and 57 hr, respectively. Leukocyte to plasma Cmax ratios for males and females were 258 (±77%) and 175 (±60%), respectively, and the AUC ratios were 804 (±31%) and 541 (±28%), respectively. The clinical relevance of these findings is unknown.


Following oral administration of multiple daily doses of 600 mg (1 tablet/day) to asymptomatic HIV-seropositive adults, mean maximum concentration in peripheral leukocytes was 252 µg/mL (±49%). Trough concentrations in peripheral leukocytes at steady-state averaged 146 µg/mL (±33%). The mean leukocyte to serum Cmax ratio was 456 (±38%) and the mean leukocyte to serum AUC ratio was 816 (±31%). The clinical relevance of these findings is unknown.


The serum protein binding of azithromycin is variable in the concentration range approximating human exposure, decreasing from 51% at 0.02 µg/mL to 7% at 2 µg/mL. Biliary excretion of azithromycin, predominantly as unchanged drug, is a major route of elimination. Over the course of a week, approximately 6% of the administered dose appears as unchanged drug in urine.


Renal Insufficiency

Azithromycin pharmacokinetics was investigated in 42 adults (21 to 85 years of age) with varying degrees of renal impairment. Following the oral administration of a single 1.0 g dose of azithromycin (4 × 250 mg capsules), the mean Cmax and AUC0–120 increased by 5.1% and 4.2%, respectively in subjects with GFR 10 to 80 mL/min compared to subjects with normal renal function (GFR >80 mL/min). The mean Cmax and AUC0–120 increased 61% and 35%, respectively in subjects with end-stage renal disease (GFR <10 mL/min) compared to subjects with normal renal function (GFR >80 mL/min). (See DOSAGE AND ADMINISTRATION.)


Hepatic Insufficiency

The pharmacokinetics of azithromycin in subjects with hepatic impairment has not been established.


The effect of azithromycin on the plasma levels or pharmacokinetics of theophylline administered in multiple doses adequate to reach therapeutic steady-state plasma levels is not known. (See PRECAUTIONS.)



Mechanism of Action


Azithromycin acts by binding to the 50S ribosomal subunit of susceptible microorganisms and, thus, interfering with microbial protein synthesis. Nucleic acid synthesis is not affected.


Azithromycin concentrates in phagocytes and fibroblasts as demonstrated by in vitro incubation techniques. Using such methodology, the ratio of intracellular to extracellular concentration was >30 after one hour incubation. In vivo studies suggest that concentration in phagocytes may contribute to drug distribution to inflamed tissues.



Microbiology


Azithromycin has been shown to be active against most strains of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section.


Aerobic Gram-Positive Microorganisms


  

Staphylococcus aureus

  

Streptococcus agalactiae

  

Streptococcus pneumoniae

  

Streptococcus pyogenes

NOTE: Azithromycin demonstrates cross-resistance with erythromycin-resistant gram-positive strains. Most strains of Enterococcus faecalis and methicillin-resistant staphylococci are resistant to azithromycin.


Aerobic Gram-Negative Microorganisms


  

Haemophilus influenzae

  

Moraxella catarrhalis

"Other" Microorganisms


  

Chlamydia trachomatis

Beta-lactamase production should have no effect on azithromycin activity.


Azithromycin has been shown to be active in vitro and in the prevention and treatment of disease caused by the following microorganisms:


Mycobacteria


  

Mycobacterium avium complex (MAC) consisting of:

  

Mycobacterium avium

  

Mycobacterium intracellulare.

The following in vitro data are available, but their clinical significance is unknown.


Azithromycin exhibits in vitro minimal inhibitory concentrations (MICs) of 2.0 µg/mL or less against most (≥90%) strains of the following microorganisms; however, the safety and effectiveness of azithromycin in treating clinical infections due to these microorganisms have not been established in adequate and well-controlled trials.


Aerobic Gram-Positive Microorganisms


  

Streptococci (Groups C, F, G)

  

Viridans group streptococci

Aerobic Gram-Negative Microorganisms


  

Bordetella pertussis

  

Campylobacter jejuni

  

Haemophilus ducreyi

  

Legionella pneumophila

Anaerobic Microorganisms


  

Bacteroides bivius

  

Clostridium perfringens

  

Peptostreptococcus species

"Other" Microorganisms


  

Borrelia burgdorferi

  

Mycoplasma pneumoniae

  

Treponema pallidum

  

Ureaplasma urealyticum

Susceptibility Testing of Bacteria Excluding Mycobacteria

The in vitro potency of azithromycin is markedly affected by the pH of the microbiological growth medium during incubation. Incubation in a 10% CO2 atmosphere will result in lowering of media pH (7.2 to 6.6) within 18 hours and in an apparent reduction of the in vitro potency of azithromycin. Thus, the initial pH of the growth medium should be 7.2–7.4, and the CO2 content of the incubation atmosphere should be as low as practical.


Azithromycin can be solubilized for in vitro susceptibility testing by dissolving in a minimum amount of 95% ethanol and diluting to working concentration with water.



Dilution Techniques


Quantitative methods are used to determine minimal inhibitory concentrations that provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds. One such standardized procedure uses a standardized dilution method1 (broth, agar or microdilution) or equivalent with azithromycin powder. The MIC values should be interpreted according to the following criteria:










MIC (µg/mL)Interpretation
≤ 2Susceptible (S)
4Intermediate (I)
≥ 8Resistant (R)

A report of "Susceptible" indicates that the pathogen is likely to respond to monotherapy with azithromycin. A report of "Intermediate" indicates that the result should be considered equivocal, and, if the microorganism is not fully susceptible to alternative, clinically feasible drugs, the test should be repeated. This category also provides a buffer zone which prevents small uncontrolled technical factors from causing major discrepancies in interpretation. A report of "Resistant" indicates that usually achievable drug concentrations are unlikely to be inhibitory and that other therapy should be selected.


Measurement of MIC or MBC and achieved antimicrobial compound concentrations may be appropriate to guide therapy in some infections. (See CLINICAL PHARMACOLOGY section for further information on drug concentrations achieved in infected body sites and other pharmacokinetic properties of this antimicrobial drug product.)


Standardized susceptibility test procedures require the use of laboratory control microorganisms. Standard azithromycin powder should provide the following MIC values:










MicroorganismMIC (µg/mL)
Escherichia coli ATCC 259222.0–8.0
Enterococcus faecalis ATCC 292121.0–4.0
Staphylococcus aureus ATCC 292130.25–1.0

Diffusion Techniques


Quantitative methods that require measurement of zone diameters also provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds. One such standardized procedure2 that has been recommended for use with disks to test the susceptibility of microorganisms to azithromycin uses the 15-µg azithromycin disk. Interpretation involves the correlation of the diameter obtained in the disk test with the minimal inhibitory concentration (MIC) for azithromycin.


Reports from the laboratory providing results of the standard single-disk susceptibility test with a 15 µg azithromycin disk should be interpreted according to the following criteria:










Zone Diameter (mm)Interpretation
≥ 18(S) Susceptible
14–17(I) Intermediate
≤ 13(R) Resistant

Interpretation should be as stated above for results using dilution techniques.


As with standardized dilution techniques, diffusion methods require the use of laboratory control microorganisms. The 15-µg azithromycin disk should provide the following zone diameters in these laboratory test quality control strains:






MicroorganismZone Diameter (mm)
Staphylococcus aureus ATCC 2592321–26
In Vitro Activity of Azithromycin Against Mycobacteria

Azithromycin has demonstrated in vitro activity against Mycobacterium avium complex (MAC) organisms. While gene probe techniques may be used to distinguish between M. avium and M. intracellulare, many studies only reported results on M. avium complex (MAC) isolates. Azithromycin has also been shown to be active against phagocytized M. avium complex (MAC) organisms in mouse and human macrophage cell cultures as well as in the beige mouse infection model.


Various in vitro methodologies employing broth or solid media at different pHs, with and without oleic acid-albumin dextrose-catalase (OADC), have been used to determine azithromycin MIC values for Mycobacterium avium complex strains. In general, azithromycin MIC values decreased 4 to 8 fold as the pH of Middlebrook 7H11 agar media increased from 6.6 to 7.4. At pH 7.4, azithromycin MIC values determined with Mueller-Hinton agar were 4 fold higher than that observed with Middlebrook 7H12 media at the same pH. Utilization of oleic acid-albumin-dextrose-catalase (OADC) in these assays has been shown to further alter MIC values. The relationship between azithromycin and clarithromycin MIC values has not been established. In general, azithromycin MIC values were observed to be 2 to 32 fold higher than clarithromycin independent of the susceptibility method employed.


The ability to correlate MIC values and plasma drug levels is difficult as azithromycin concentrates in macrophages and tissues. (See CLINICAL PHARMACOLOGY)



Drug Resistance


Complete cross-resistance between azithromycin and clarithromycin has been observed with Mycobacterium avium complex (MAC) isolates. In most isolates, a single point mutation at a position that is homologous to the Escherichia coli positions 2058 or 2059 on the 23S rRNA gene is the mechanism producing this cross-resistance pattern.3,4 Mycobacterium avium complex (MAC) isolates exhibiting cross-resistance show an increase in azithromycin MICs to ≥128 µg/mL with clarithromycin MICs increasing to ≥32 µg/mL. These MIC values were determined employing the radiometric broth dilution susceptibility testing method with Middlebrook 7H12 medium. The clinical significance of azithromycin and clarithromycin cross-resistance is not fully understood at this time but preclinical data suggest that reduced activity to both agents will occur after M. avium complex strains produce the 23S rRNA mutation.



Susceptibility testing for Mycobacterium avium complex (MAC)


The disk diffusion techniques and dilution methods for susceptibility testing against Gram-positive and Gram-negative bacteria should not be used for determining azithromycin MIC values against mycobacteria. In vitro susceptibility testing methods and diagnostic products currently available for determining minimal inhibitory concentration (MIC) values against Mycobacterium avium complex (MAC) organisms have not been standardized or validated. Azithromycin MIC values will vary depending on the susceptibility testing method employed, composition and pH of media and the utilization of nutritional supplements. Breakpoints to determine whether clinical isolates of M. avium or M. intracellulare are susceptible or resistant to azithromycin have not been established.


The clinical relevance of azithromycin in vitro susceptibility test results for other mycobacterial species, including Mycobacterium tuberculosis, using any susceptibility testing method has not been determined.



Indications and Usage for Zithromax


Zithromax (azithromycin) is indicated for the treatment of patients with mild to moderate infections (pneumonia: see WARNINGS) caused by susceptible strains of the designated microorganisms in the specific conditions listed below.



Sexually Transmitted Diseases


Non-gonococcal urethritis and cervicitis due to Chlamydia trachomatis.


Zithromax, at the recommended dose, should not be relied upon to treat gonorrhea or syphilis. Antimicrobial agents used in high doses for short periods of time to treat non-gonococcal urethritis may mask or delay the symptoms of incubating gonorrhea or syphilis. All patients with sexually-transmitted urethritis or cervicitis should have a serologic test for syphilis and appropriate cultures for gonorrhea performed at the time of diagnosis. Appropriate antimicrobial therapy and follow-up tests for these diseases should be initiated if infection is confirmed.


Appropriate culture and susceptibility tests should be performed before treatment to determine the causative organism and its susceptibility to azithromycin. Therapy with Zithromax may be initiated before results of these tests are known; once the results become available, antimicrobial therapy should be adjusted accordingly.


To reduce the development of drug-resistant bacteria and maintain the effectiveness of Zithromax (azithromycin) and other antibacterial drugs, Zithromax (azithromycin) should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.



Mycobacterial Infections


Prophylaxis of Disseminated Mycobacterium avium complex (MAC) Disease

Zithromax, taken alone or in combination with rifabutin at its approved dose, is indicated for the prevention of disseminated Mycobacterium avium complex (MAC) disease in persons with advanced HIV infection. (See DOSAGE AND ADMINISTRATION, CLINICAL STUDIES)


Treatment of Disseminated Mycobacterium avium complex (MAC) Disease

Zithromax, taken in combination with ethambutol, is indicated for the treatment of disseminated MAC infections in persons with advanced HIV infection. (See DOSAGE AND ADMINISTRATION, CLINICAL STUDIES)



Contraindications


Zithromax is contraindicated in patients with known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide antibiotic. Zithromax is contraindicated in patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin.



Warnings



Hypersensitivity


Serious allergic reactions, including angioedema, anaphylaxis, and dermatologic reactions including Stevens Johnson Syndrome and toxic epidermal necrolysis have been reported rarely in patients on azithromycin therapy. Although rare, fatalities have been reported (see CONTRAINDICATIONS). Despite initially successful symptomatic treatment of the allergic symptoms, when symptomatic therapy was discontinued, the allergic symptoms recurred soon thereafter in some patients without further azithromycin exposure. These patients required prolonged periods of observation and symptomatic treatment. The relationship of these episodes to the long tissue half-life of azithromycin and subsequent prolonged exposure to antigen is unknown at present.


If an allergic reaction occurs, the drug should be discontinued and appropriate therapy should be instituted. Physicians should be aware that reappearance of the allergic symptoms may occur when symptomatic therapy is discontinued.



Hepatotoxicity


Abnormal liver function, hepatitis, cholestatic jaundice, hepatic necrosis, and hepatic failure have been reported, some of which have resulted in death. Discontinue azithromycin immediately if signs and symptoms of hepatitis occur.



Clostridium Difficile-associated diarrhea


Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including Zithromax, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile.


C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.


If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.



Precautions



General


Because azithromycin is principally eliminated via the liver, caution should be exercised when azithromycin is administered to patients with impaired hepatic function. Due to the limited data in subjects with GFR<10 mL/min, caution should be exercised when prescribing azithromycin in these patients. (See CLINICAL PHARMACOLOGY - Renal Insufficiency).


Prolonged cardiac repolarization and QT interval, imparting a risk of developing cardiac arrhythmia and torsades de pointes, have been seen in treatment with other macrolides. A similar effect with azithromycin cannot be completely ruled out in patients at increased risk for prolonged cardiac repolarization.


Exacerbation of symptoms of myasthenia gravis and new onset of myasthenic syndrome have been reported in patients receiving azithromycin therapy.


Prescribing Zithromax (azithromycin) in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.



Information for Patients


Zithromax tablets may be taken with or without food. However, increased tolerability has been observed when tablets are taken with food.


Zithromax for oral suspension in single 1 g packets can be taken with or without food after constitution.


Patients should also be cautioned not to take aluminum- and magnesium-containing antacids and azithromycin simultaneously.


The patient should be directed to discontinue azithromycin immediately and contact a physician if any signs of an allergic reaction occur.


Patients should be counseled that antibacterial drugs including Zithromax (azithromycin) should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When Zithromax (azithromycin) is prescribed to treat bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by Zithromax (azithromycin) or other antibacterial drugs in the future.


Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued. Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic. If this occurs, patients should contact their physician as soon as possible.



Drug Interactions


Aluminum- and magnesium-containing antacids reduce the peak serum levels (rate) but not the AUC (extent) of azithromycin (500 mg) absorption.


Administration of cimetidine (800 mg) two hours prior to azithromycin had no effect on azithromycin (500 mg) absorption.


A single oral dose of 1200 mg azithromycin (2 × 600 mg Zithromax tablets) did not alter the pharmacokinetics of a single 800 mg oral dose of fluconazole in healthy adult subjects.


Total exposure (AUC) and half-life of azithromycin following the single oral tablet dose of 1200 mg were unchanged and the reduction in Cmax was not significant (mean decrease of 18%) by coadministration with 800 mg fluconazole.


A single oral dose of 1200 mg azithromycin (2 × 600 mg Zithromax tablets) had no significant effect on the pharmacokinetics of indinavir (800 mg indinavir tid for 5 days) in healthy adult subjects.


Coadministration of a single oral dose of 1200 mg azithromycin (2 × 600 mg Zithromax tablets) with steady-state nelfinavir (750 mg tid) to healthy adult subjects produced a decrease of approximately 15% in mean AUC0–8 of nelfinavir and its M8 metabolite. Mean Cmax of nelfinavir and its M8 metabolite were not significantly affected. No dosage adjustment of nelfinavir is required when nelfinavir is coadministered with azithromycin.


Coadministration of nelfinavir (750 mg tid) at steady state with a single oral dose of 1200 mg azithromycin increased the mean AUC0–∞ of azithromycin by approximately a factor of 2-times (range of up to 4 times) of that when azithromycin was given alone. The mean Cmax of azithromycin was also increased by approximately a factor of 2-times (range of up to 5 times) of that when azithromycin was given alone. Dose adjustment of azithromycin is not recommended. However, when administered in conjunction with nelfinavir, close monitoring for known side effects of azithromycin, such as liver enzyme abnormalities and hearing impairment, is warranted. (See ADVERSE REACTIONS.)


Following administration of trimethoprim/sulfamethoxazole DS (160 mg/800 mg) for 7 days to healthy adult subjects, coadministration of 1200 mg azithromycin (2 × 600 mg Zithromax tablets) on the 7th day had no significant effects on peak concentrations (Cmax), total exposure (AUC), and the urinary excretion of either trimethoprim or sulfamethoxazole.


Coadministration of trimethoprim/sulfamethoxazole DS for 7 days had no significant effect on the peak concentration (Cmax) and total exposure (AUC) of azithromycin following administration of the single 1200 mg tablet dose to healthy adult subjects.


Administration of a 600 mg single oral dose of azithromycin had no effect on the pharmacokinetics of efavirenz given at 400 mg doses for 7 days to healthy adult subjects.


Efavirenz, when administered at a dose of 400 mg for seven days produced a 22% increase in the Cmax of azithromycin administered as a 600 mg single oral dose, while the AUC of azithromycin was not affected.


Azithromycin (500 mg Day 1, 250 mg Days 2–5) did not affect the plasma levels or pharmacokinetics of theophylline administered as a single intravenous dose. The effect of azithromycin on the plasma levels or pharmacokinetics of theophylline administered in multiple doses resulting in therapeutic steady-state levels of theophylline is not known. However, concurrent use of macrolides and theophylline has been associated with increases in the serum concentrations of theophylline. Therefore, until further data are available, prudent medical practice dictates careful monitoring of plasma theophylline levels in patients receiving azithromycin and theophylline concomitantly.


Although, in a study of 22 healthy men, a 5-day course of azithromycin did not affect the prothrombin time from a subsequently administered dose of warfarin, spontaneous post-marketing reports suggest that concomitant administration of azithromycin may potentiate the effects of oral anticoagulants. Prothrombin times should be carefully monitored while patients are receiving azithromycin and oral anticoagulants concomitantly.


Dose adjustments are not indicated when azithromycin and zidovudine are coadministered. When zidovudine (100 mg q3h ×5) was coadministered with daily azithromycin (600 mg, n=5 or 1200 mg, n=7), mean Cmax, AUC and Clr increased by 26% (CV 54%), 10% (CV 26%) and 38% (CV 114%), respectively. The mean AUC of phosphorylated zidovudine increased by 75% (CV 95%), while zidovudine glucuronide Cmax and AUC increased by less than 10%. In another study, addition of 1 gram azithromycin per week to a regimen of 10 mg/kg daily zidovudine resulted in 25% (CV 70%) and 13% (CV 37%) increases in zidovudine Cmax and AUC, respectively. Zidovudine glucuronide mean Cmax and AUC increased by 16% (CV 61%) and 8.0% (CV 32%), respectively.


Doses of 1200 mg/day azithromycin for 14 days in 6 subjects increased Cmax of concurrently administered didanosine (200 mg q.12h) by 44% (54% CV) and AUC by 14% (23% CV). However, none of these changes were significantly different from those produced in a parallel placebo control group of subjects.


Preliminary data suggest that coadministration of azithromycin and rifabutin did not markedly affect the mean serum concentrations of either drug. Administration of 250 mg azithromycin daily for 10 days (500 mg on the first day) produced mean concentrations of azithromycin 1 day after the last dose of 53 ng/mL when coadministered with 300 mg daily rifabutin and 49 mg/mL when coadministered with placebo. Mean concentrations 5 days after the last dose were 23 ng/mL and 21 ng/mL in the two groups of subjects. Administration of 300 mg rifabutin for 10 days produced mean concentrations of rifabutin one half day after the last dose of 60 mg/ml when coadministered with daily 250 mg azithromycin and 71 ng/mL when coadministered with placebo. Mean concentrations 5 days after the last dose were 8.1 ng/mL and 9.2 ng/mL in the two groups of subjects.


The following drug interactions have not been reported in clinical trials with azithromycin; however, no specific drug interaction studies have been performed to evaluate potential drug-drug interaction. Nonetheless, they have been observed with macrolide products. Until further data are developed regarding drug interactions when azithromycin and these drugs are used concomitantly, careful monitoring of patients is advised:


Digoxin–elevated digoxin levels.


Ergotamine or dihydroergotamine–acute ergot toxicity characterized by severe peripheral vasospasm and dysesthesia.


Triazolam–decrease the clearance of triazolam and thus may increase the pharmacologic effect of triazolam.


Drugs metabolized by the cytochrome P450 system–elevations of serum carbamazepine, cyclosporine, hexobarbital, and phenytoin levels.



Laboratory Test Interactions


There are no reported laboratory test interactions.



Carcinogenesis, Mutagenesis, Impairment of Fertility


Long-term studies in animals have not been performed to evaluate carcinogenic potential. Azithromycin has shown no mutagenic potential in standard laboratory tests: mouse lymphoma assay, human lymphocyte clastogenic assay, and mouse bone marrow clastogenic assay.



Pregnancy


Teratogenic Effects. Pregnancy Category B

Reproduction studies have been performed in rats and mice at doses up to moderately maternally toxic dose levels (i.e., 200 mg/kg/day). These doses, based on a mg/m2 basis, are estimated to be 4 and 2 times, respectively, the human daily dose of 500 mg.


With regard to the MAC treatment dose of 600 mg daily, on a mg/m2/day basis, the doses in rats and mice are approximately 3.3 and 1.7 times the human dose, respectively.


With regard to the MAC prophylaxis dose of 1200 mg weekly, on a mg/m2/day basis, the doses in rats and mice are approximately 2 and 1 times the human dose, respectively.


No evidence of impaired fertility or harm to the fetus due to azithromycin was found. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, azithromycin should be used during pregnancy only if clearly needed.



Nursing Mothers


It is not known whether azithromycin is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when azithromycin is administered to a nursing woman.



Pediatric Use


In controlled clinical studies, azithromycin has been administered to pediatric patients ranging in age from 6 months to 12 years. For information regarding the use of Zithromax (azithromycin for oral suspension) in the treatment of pediatric patients, please refer to the INDICATIONS AND USAGE and DOSAGE AND ADMINISTRATION sections of the prescribing information for Zithromax (azithromycin for oral suspension) 100 mg/5 mL and 200 mg/5 mL bottles.


Safety in HIV-Infected Pediatric Patients

Safety and efficacy of azithromycin for the prevention or treatment of MAC in HIV-infected children have not been established. Safety data are available for 72 children 5 months to 18 years of age (mean 7 years) who received azithromycin for treatment of opportunistic infections. The mean duration of therapy was 242 days (range 3–2004 days) at doses of <1 to 52 mg/kg/day (mean 12 mg/kg/day). Adverse events were similar to those observed in the adult population, most of which involved the gastrointestinal tract. Treatment related reversible hearing impairment in children was observed in 4 subjects (5.6%). Two (2.8%) children prematurely discontinued treatment due to side effects: one due to back pain and one due to abdominal pain, hot and cold flushes, dizziness, headache, and numbness. A third child discontinued due to a laboratory abnormality (eosinophilia). The protocols upon which these data are based specified a daily dose of 10–20 mg/kg/day (oral and/o