Roxithromycin and controlled release theophylline, an interaction study.

A clinical trial, involving 16 male subjects affected by a relapse of chronic bronchitis, was performed in order to evaluate the possible interference of roxithromycin (RU 28965) with theophylline plasma levels. Theophylline was administered to patients as a controlled release formulation. Results did not show any clinically relevant change in theophylline blood levels, implying the conclusion that the new macrolide roxithromycin can be administered simultaneously with a controlled release theophylline.