Increased plasma conc of carbamazepine & terfenadine. Increased serum digoxin conc. Decreased serum conc w/ rifabutin or rifampin. Increased AUC of theophylline. Potentiated effects of warfarin. Acute ergot toxicity w/ ergotamine or dihydroergotamine. CNS effects w/ triazolam. Increased serum levels of cyclosporine, tacrolimus, hexobarbital, phenytoin, alfentanil, quinidine/disopyramide, lovastatin, bromocriptine, valproate, astemizole & CYP450-metabolised drugs. Ventricular arrhythmias w/ non-sedative antihistamines eg, astemizole, terfenadine & cisapride. Lowered Cmax
, AUC & delayed Tmax
w/ zidovudine. Metgyl
Disulfiram-like effects w/ alcohol. Potentiated effects of coumarin- or indandione-derivative anticoagulants. Decreased hepatic metabolism w/ cimetidine. Confusion & psychotic reaction w/ disulfiram. Increased lithium conc. Decreased t½
& plasma conc w/ phenobarb. Increased plasma conc of phenytoin. Spuriously low values on AST assay. Omilock
Increased bioavailability of digoxin. Increased plasma conc of diazepam, phenytoin & warfarin.