RiteMED Azithromycin

Each film-coated tablet contains: Azithromycin (as dihydrate), USP 500 mg.

Azithromycin is indicated for respiratory tract infections, otitis media, skin and soft-tissue infections, uncomplicated genital chlamydial infections and non-gonococcal urethritis mild or moderate typhoid due to multiple antibacterial resistant organisms and prophylaxis of endocarditis in children.

The usual oral adult dose of Azithromycin is 500 mg as a single dose daily for 3 days. Alternatively, an initial dose of 500 mg may be followed by 250 mg daily for a further 4 days.
For uncomplicated genital infections caused by Chlamydia trachomatis and chancroid, 1 g of Azithromycin is given as a single dose. A single dose 2 g has been given for uncomplicated gonorrhea.
For the treatment of granuloma inguinale, an initial dose of 1 g followed by 500 mg daily may be given, or 1 g may be given once a week for at least 3 weeks, until all lesions have completely healed.
For prophylaxis of disseminated MAC infections, Azithromycin 1.2 g may begiven once weekly.
For treatment or secondary prophylaxis, 500 mg once daily should be given with other antimycobacterials.
For mild or moderate typhoid caused by multidrug-resistant strains, 500 mg once daily may be given for 7 days.

Treatment is symptomatic and supportive.

Azithromycin is contraindicated in patients with known hypersensitivity to Azithromycin, Erythromycin, any macrolide or ketolide antibiotic.

Rare serious allergic reactions, including angioedema and anaphylaxis, have been reported rarely in patients on Azithromycin therapy. 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. After the diagnosis of pseudomembranous colitis has been established, therapeutic measures should be initiated. Mild cases of pseudomembranous colitis usually respond to discontinuation of the drug alone. In moderate to severe cases, consideration should be given to management with fluids and electrolytes, protein supplementation, and treatment with an antibacterial drug clinically effective against Clostridium difficile colitis.

General: Because Azithromycin is principally eliminated via the liver, caution should be exercised when Azithromycin is administered to patients with impaired hepatic function.
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. Prescribing 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: Azithromycin tablets may be taken with or without food. However, increased tolerability has been observed when tablets are taken with food. 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 Azithromycin should only be used to treat bacterial infections. They do not treat viral infections. When 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 decrease the effectiveness of the immediate treatment and increase the likelihood that bacteria will develop resistance and will not be treatable by Azithromycin or other antibacterial drugs in the future.

In clinical trials, most of the reported side effects were mild to moderate in severity and were reversible upon discontinuation of the drug. Approximately 0.7% of the patients from the multiple-dose clinical trials discontinued Azithromycin therapy because of treatment-related side effects. Most of the side effects leading to discontinuation were related to the gastrointestinal tract, e.g. nausea, vomiting, diarrhea, or abdominal pain. Rare but potentially serious side effects were angioedema and cholestatic jaundice.

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 Azithromycin 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 C_max was not significant by coadministration with 800 mg fluconazole.
A single oral dose of 1200 mg Azithromycin had no significant effect on the pharmacokinetics of indinavir in 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. Azithromycin did not affect the plasma levels to pharmacokinetics of theophylline administered as a single intravenous dose. 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. Azithromycin did not affect the prothrombin time response to a single dose of warfarin. However, prudent medical practice dictates careful monitoring of prothrombin time in all patients treated with Azithromycin and warfarin concomitantly. Concurrent use of macrolides and warfarin in clinical practice has been associated with increased anticoagulant effects. Dose adjustments are not indicated when Azithromycin and zidovudine are coadministered. Doses of 1200 mg/day Azithromycin for 14 days in 6 subjects increased C_max of concurrently administered didanosine by 44%.
Preliminary data suggest that coadministration of Azithromycin and rifabutin did not markedly affect the mean serum concentrations of either drug. 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.

Store at temperatures not exceeding 30°C.

Macrolides

J01FA10 - azithromycin ; Belongs to the class of macrolides. Used in the systemic treatment of infections.

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