RiteMED Azithromycin 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 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.