When used orally, ketoconazole has been associated with hepatic toxicity, including some fatalities. Patients receiving this drug should be informed by the physician of the risk and should be closely monitored. See WARNINGS and PRECAUTIONS.

Coadministration of terfenadine with ketoconazole tablets is contraindicated. Rare cases of serious cardiovascular adverse events including death, ventricular tachycardia and torsades de pointes have been observed in patients taking ketoconazole concomitantly with terfenadine, due to increased terfenadine concentrations induced by ketoconazole tablets. See CONTRAINDICATIONS, WARNINGS and PRECAUTIONS.

Pharmacokinetic data indicate that oral ketoconazole inhibits the metabolism of astemizole, resulting in elevated plasma levels of astemizole and its active metabolite desmethylastemizole which may prolong QT intervals. Coadministration of astemizole with ketoconazole table ts is therefore contraindicated. See CONTRAINDICATIONS, WARNINGS and PRECAUTIONS.

Coadministration of cisapride with ketoconazole is contraindicated. Serious cardiovascular adverse events including ventricular tachycardia, ventricular fibrillation and torsades de pointes have occurred in patients taking ketoconazole concomitantly with cisapride. See CONTRAINDICATIONS, WARNINGS, and PRECAUTIONS sections.