Fungazol Drug Interactions

Concomitant administration of ketoconazole with the following drugs may result in decreased plasma concentrations of ketoconazole.
Antacids: increased gastric pH may inhibit ketoconazole absorption.
Consider giving antacid ≥2 hours after ketoconazole.
Sucralfate: the therapeutic effects of ketoconazole may be reduced; therefore, should be administered ≥2 hours before sucralfate.
Proton pump inhibitor: the bioavailability of ketoconazole may be decreased because of a possible reduction in tablet dissolution in the presence of a high gastric pH.
Histamine H₂ antagonists: increased gastric pH may inhibit ketoconazole absorption.
Isoniazid: bioavailability of ketoconazole may be decreased.
Rifampicin: decreased serum levels of either drug may occur. Avoid concurrent use if possible.
Theophyllines: decreased absorption of theophylline may occur, resulting in decreased theophylline serum levels.
Ketoconazole may increase the plasma levels of cyclosporine, tacrolimus, methylprednisolone, midazolam, triazolam, digoxin, hypoglycemic agents, indinavir, ritonavir, saquinavir, tricyclic antidepressants, carbamazepine, quinidine, sulfonylureas, buspirone, HMG-CoA reductase inhibitors, nisoldipine, zolpidem, warfarin, corticosteroids and drugs primarily metabolized by the cytochrome P-450 3A4 enzyme system that could increase or prolong both therapeutic and adverse effects. Therefore, appropriate dosage adjustments may be necessary.
Coadministration of ketoconazole with terfenadine, astemizole and/or cisapride is contraindicated. Ketoconazole inhibits the metabolism of terfenadine, astemizole and cisapride resulting in increased plasma concentrations of these drugs which may prolong QT intervals. Serious cardiovascular adverse events including ventricular tachycardia, ventricular fibrillation and torsades de pointes have been observed in patients taking ketoconazole concomitantly with these drugs.