Manifestations of carbamazepine toxicity may occur. Cardiac arrhythmias including QT prolongation, ventricular tachycardia, ventricular fibrillation & torsades de pointes w/ cisapride/pimozide. Ventricular fibrillation, QT interval prolongation & marked increased elimination t½
of disopyramide. Increased conc of HMG-CoA reductase inhibitors. Increased metabolism w/ rifampicin, rifabutin, rifapentine. Increased frequency of uveitis w/ rifabutin. Increased serum level of terfenadine & astemizole. Higher serum conc of tolterodine. Increased exposure & possible related toxicities of quetiapine. Inhibits metabolism of alfentanil, bromocriptine, cilostazole, hexobarbital, ibrutinib, methylprednisolone, phenytoin, sirolimus, valproate & vinblastine. May induce metabolism w/ St. John's wort. Increased conc & AUC of amprenavir. Increased AUC w/ delavirdine. Decreased exposure w/ etravirine. Increased conc of indinavir. Increased conc w/ fixed combination of lopinavir & ritonavir. Decreased plasma conc & AUC w/ nevirapine. Increased plasma conc of saquinavir. Decreased steady-state conc of zidovudine. Increased anticoagulant effect of warfarin & acenocoumarol. Serious risk of CNS effects w/ triazolobenzodiazepines (eg, alprazolam, triazolam) & benzodiazepines (eg, midazolam). Risk of hypotension w/ Ca channel blockers (eg, verapamil, amlodipine, diltiazem, nifedipine). Elevated ciclosporin level. Increased exposure to colchicine. Elevated serum digoxin levels. Fatal toxic epidermal necrolysis & fulminant hepatitis w/ disulfiram. Acute ergot toxicity. Increased steady-state trough serum conc & AUC w/ fluconazole. Delirium w/ fluoxetine. Increased plasma levels w/ itraconazole. Increased Cmax
, AUC and elimination t½
of omeprazole. Hypoglycemia w/ certrain hypoglycemic drugs eg, nateglinide, pioglitazone, repaglinide & rosiglitazone. Increased phosphodiesterase inhibtor (eg, sildenafil, tadalafil, vardenafil) exposure). Increased tacrolimus plasma levels. Increased serum theophylline. Darifenacin; erlotinib; eszopiclone; atazanavir.