Azith Drug Interactions

Antacids: Oral Azithromycin preparations should not be administered simultaneously with aluminum-or magnesium-containing antacids. Administration of oral Azithromycin with an aluminum- and magnesium hydroxide-containing antacid resulted in a decreased rate of absorption of Azithromycin. In patients receiving both Azithromycin and antacids, the drugs should not be taken simultaneously.
Cyclosporine: Coadministration of Azithromycin with cyclosporine will significantly increase plasma concentration of cyclosporine. Consequently, caution should be exercised before considering concurrent administration of these drugs. If co-administration of these drugs is necessary, cyclosporine levels should be monitored and the dose adjusted accordingly.
Digoxin: Concomitant administration of macrolide antibiotics, including Azithromycin with P-glycoprotein substrates, such as digoxin, has been reported to result in increased serum levels of the P-glycoprotein substrates. Therefore, if Azithromycin and P-glycoprotein substrates, such as digoxin are administered concomitantly, the possibility of elevated serum digoxin concentrations should be considered. Clinical monitoring, and possibly serum digoxin levels, during treatment with Azithromycin and after its discontinuation are necessary.
Ergot: In patients receiving ergot derivatives, ergotism has been precipitated by co-administration of some macrolide antibiotics. Azithromycin and ergot derivatives should not be co-administered.
Atorvastatin: Coadministration of atorvastatin and Azithromycin did not alter the plasma concentrations of atorvastatin (based on a HMG CoA-reductase inhibition assay). However, post-marketing cases of rhabdomyolysis in patients receiving Azithromycin with statins have been reported.
Pimozide: Prolongation of QT interval and, rarely, serious cardiovascular effects, including ventricular arrhythmias and death, have been reported in patients receiving drugs that inhibit the cytochrome P-450 isoenzyme concomitantly with pimozide. Macrolide antibiotics may inhibit metabolism of pimozide, resulting in increased plasma concentrations of unchanged drug. Because such alterations in pharmacokinetics of pimozide may be associated with prolongation of the QT and QT_c interval. Consequently concomitant administration of pimozide and Azithromycin is contraindicated.
Coumarin-type oral anticoagulants: In a study, Azithromycin did not alter the anticoagulant effect of a single dose of warfarin administered to healthy volunteers. There have been reports received in the post-marketing period of potentiated anticoagulation subsequent to co-administration of Azithromycin and coumarin-type oral anticoagulants. Although a causal relationship has not been established, consideration should be given to the frequency of monitoring prothrombin time when Azithromycin is used in patients receiving coumarin-type oral anticoagulants.
Zidovudine: Coadministration of Azithromycin with zidovudine results in the zidovudine plasma level or urinary excretion of zidovudine or its glucuronide metabolite. However, administration of Azithromycin increased the concentrations of phosphorylated zidovudine, the clinically active metabolite, in peripheral blood mononuclear cells. The clinical significance of this finding is unclear, but it may be of benefit to patients.
Azithromycin does not interact significantly with the hepatic cytochrome P450 system. It is not believed to undergo the pharmacokinetic drug interactions as seen with erythromycin and other macrolides. Hepatic cytochrome P450 induction or inactivation via cytochrome-metabolite complex does not occur with Azithromycin.