Safety

Zmax (azithromycin extended release) for oral suspension

Detailed View: Safety Labeling Changes Approved By FDA Center for Drug Evaluation and Research (CDER)

July 2015

Summary View

ADVERSE REACTIONS

Laboratory Abnormalities
  • In subjects with normal baseline values, the following clinically significant laboratory abnormalities (irrespective of drug relationship) were reported in Zmax clinical trials in adults and pediatric patients:

Adults:

  • Laboratory abnormalities with an incidence of greater than or equal to 1%: reduced lymphocytes and increased eosinophils; reduced bicarbonate. Laboratory abnormalities with an incidence of less than 1%: leukopenia, neutropenia, elevated bilirubin, AST, ALT, BUN, creatinine, alterations in potassium. Where follow-up was provided, changes in laboratory tests appeared to be reversible.

Pediatric Patients:

  • Laboratory abnormalities with an incidence of greater than or equal to 1%: elevated eosinophils, BUN, and potassium; decreased lymphocytes; and alterations in neutrophils; with an incidence of less than 1%: elevated SGOT, SGPT and creatinine; decreased potassium; and alterations in sodium and glucose.

DRUG INTERACTIONS

Nelfinavir
  • Co-administration of nelfinavir at steady-state with a single oral dose of azithromycin resulted in increased azithromycin serum concentrations. Although a dose adjustment of azithromycin is not recommended when administered in combination with nelfinavir, close monitoring for known adverse reactions of azithromycin, such as liver enzyme abnormalities and hearing impairment, is warranted.
Warfarin
  • Spontaneous post-marketing reports suggest that concomitant administration of azithromycin may potentiate the effects of oral anticoagulants such as warfarin, although the prothrombin time was not affected in the dedicated drug interaction study with azithromycin and warfarin. Prothrombin times should be carefully monitored while patients are receiving azithromycin and oral anticoagulants concomitantly.
Potential Drug-Drug Interactions with Macrolides
  • Interactions with digoxin or phenytoin have not been reported in clinical trials with azithromycin; however, no specific drug interaction studies have been performed to evaluate potential drug-drug interactions. However, drug interactions have been observed with other macrolide products. Until further data are developed regarding drug interactions when digoxin or phenytoin are used concomitantly with azithromycin careful monitoring of patients is advised.

 

March 2012

Summary View

WARNINGS AND PRECAUTIONS

Prolongation of the QT interval
  • Cases of torsades de pointes have been spontaneously reported during postmarketing surveillance in patients receiving azithromycin. Although the absolute risk is unknown, it appears to be low with azithromycin likely due to the lack of appreciable drug interactions, and the observation that it is rarely reported as a postmarketing adverse event. However, it would be prudent to avoid use in patients with known prolongation of the QT interval, patients with ongoing proarrhythmic conditions such as uncorrected hypokalemia or hypomagnesemia, clinically significant bradycardia, and in patients receiving Class IA (quinidine, procainamide) or Class III (dofetilide, amiodarone, sotalol) antiarrhythmic agents. Elderly patients may be more susceptible to drug-associated effects on the QT interval.

 

June 2011

Summary View 

CONTRAINDICATIONS

Cholestatic jaundice/hepatic dysfunction
  • Zmax is contraindicated in patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin.

WARNINGS

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.

ADVERSE REACTIONS

Postmarketing Experience
  • Liver/Biliary: Adverse reactions related to hepatic dysfunction have been reported in postmarketing experience with azithromycin. 

 

Page Last Updated: 08/14/2015
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