Floctil Drug Interactions

Antacids: In patients receiving Azithromycin and antacids, Floctil should be taken at least 1 hour or 2 hours after the antacid.
Carbamazepine: In a pharmacokinetic interaction study in healthy volunteers, no significant effect was observed on the plasma levels of Carbamazepine or its active metabolite.
Cimetidine: A single dose of Cimetidine administered 2 hours before Floctil had no effect on the pharmacokinetics of Azithromycin.
Cyclosporin: In a pharmacokinetic study with healthy volunteers that were administered a 500 mg/day oral dose of Azithromycin for 3 days and were then administered a single 10 mg/kg oral dose of Cyclosproine C_max and AUC_0-5 were found to be significantly elevated (by 24% and 21% respectively), however no significant changes were seen in AUC_0-∞. Consequently, caution should be exercised before considering co-administration of these two drugs. If co-administration is necessary, Cyclosporin levels should be monitored and the dose adjusted accordingly.
Digoxin: Some of the macrolide antibiotics have been reported to impair the metabolism of Digoxin (in the gut) in some patients. Therefore, in patients receiving concomitant Floctil and Digoxin the possibility of raised Digoxin levels should be borne in mind, and Digoxin levels monitored.
Ergot derivatives: Because of the theoretical possibility of ergotism, Floctil and ergot derivatives should not be co-administered.
Methylprednisolone: In a pharmacokinetic interaction study in healthy volunteers, Floctil had no significant effect on the pharmacokinetics of Methylprednisolone.
Terfenadine: Because of the occurrence of serious dysarrhythmias secondary to prolongation of the QTc interval in patients receiving other anti-infectives in conjunction with Terfenadine, pharmacokinetic interaction studies have been performed. These studies have reported no evidence of an interaction between Azithromycin and Terfenaine. There have been rare cases reported where the possibility of such an interaction could not be entirely excluded; however there was no specific evidence that such an interaction had occurred. As with other macrolides, Floctil should be administered with caution in combination with Terfenadine.
Theophylline: Theophylline levels may be increased in patients taking Floctil.
Coumarin-type oral anticoagulants: In a pharmacodynamic interaction study, Floctil did not alter the anticoagulant effect of a single 15 mg 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: Single 1000 mg doses and multiple 1200 mg or 600 mg doses of Azithromycin did not affect the plasma pharmacokinetics 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.
Didanosine: Co-administration of daily doses of 1200 mg Azithromycin with Didanosine in 6 subjects did not appear to affect the pharmacokinetics of Didanosine as compared with placebo.
Rifabutin: Co-administration of Azithromycin and Rifabutin did not affect the serum concentration of either drug. Neutropenia was observed in subjects receiving concomitant treatment of Azithromycin and Rifabutin. Although neutropenia has been associated with the use of Rifabutin, a causal relationship to combination with Azithromycin has not been established.