May increase incidence of hepatotoxicity w/ other hepatotoxic medications. Concurrent ingestion of alcohol may result in disulfiram-like reactions. Concurrent use elevates plasma conc of oral midazolam or triazolam; astemizole or terfenadine; cisapride; ciclosporin & tacrolimus. May reduce absorption w/ antacids or anticholinergics/antispasmodic, histamine H2
-receptor antagonists or omeprazole & sucralfate; didanosine. May increase serum digoxin conc. Increases AUC of indinavir. May increase metabolism by rifampicin. Decrease serum conc w/ INH. May increase anticoagulant effects w/ warfarin.