Azithromycin and terfenadine: Lack of drug interaction*

✍ Scribed by Harris, Stuart; Hilligoss, Donald M.; Colangelo, Philip M.; Eller, Mark; Okerholm, Richard

• Book ID: 103037324
• Publisher: Nature Publishing Group
• Year: 1995
• Tongue: English
• Weight: 637 KB
• Volume: 58
• Category: Article
• ISSN: 0009-9236
• DOI: 10.1016/0009-9236(95)90247-3

✦ Synopsis

Azithromycin and terfenadine: Lack of drug interaction

A double-blind placebo-controlled study was conducted in healthy men to determine the effect of coadministration of azithromycin on the pharmacodynamics and pharmacokinetics of terfenadhre. Administration of 500 mg azithromycin for 1 day and 250 mg on 4 subsequent days did not affect the pharmacokinetics of the pharmacologically active terfenadine carboxylate metabolite when 60 mg terfenadine was given twice daily for 12 days, starting 7 days before azithromycin administration. Terfenadine alone resulted in a 0.010 msec increase in the rate-corrected QT interval (QT,), but the incremental effects of azithromycin and placebo on QT, in volunteers receiving terfenadine were not statistically different. It is concluded that the potentially life-threatening disorders that have been attributed to a pharmacokinetic interaction between macrolide antibiotics and terfenadine are unlikely to take place in patients treated simultaneously with azithromycin and terfenadine.