Decreased AUC & shorter t½
w/ rifampicin. Increased plasma conc w/ hydrochlorothiazide. Increased prothrombin time w/ warfarin. Increased midazolam, cyclosporin conc. Prolonged serum t½
of sulphonylureas. Increased phenytoin, terfenadine, rifabutin, tacrolimus serum plasma levels. Increased AUC of ethinyloestradiol, levonorgestrel, zidovudine. Decreased theophylline mean plasma clearance. Cardiac events eg, Torsade de pointes w/ cisapride. Elevated serum levels of CYP450-metabolised drugs.