Drug-Drug:
- Ketoconazole is a strong inhibitor of the CYP3A4 isoenzyme
- May significantly ↑ levels and risk of torsades de pointes with dofetilide, disopyramide, dronedarone, quinidine, pimozide, ranolazine, and methadone; concurrent use contraindicated
- May significantly ↑ levels and risk of sedation with alprazolam, midzolam (PO), and triazolam; concurrent use contraindicated
- May significantly ↑ levels and risk of myopathy with lovastatin and simvastatin; concurrent use contraindicated
- May significantly ↑ levels and risk of toxicity with nisoldipine, felodipine, eplerenone, irinotecan, lurasidone, colchicine, tolvaptan, ergotamine, and dihydroergotamine; concurrent use contraindicated
- May ↑ levels of cyclosporine, tacrolimus, amlodipine, nicardipine, nifedipine, verapamil, aliskiren, budesonide, ciclesonide, dexamethasone, fluticasone, methylprednisolone, atorvastatin, bosentan, rifabutin, buspirone, cilostazol, digoxin, clarithromycin, erythromycin, haloperidol, midazolam (IV), quetiapine, ramelteon, risperidone, warfarin (↑ risk of bleeding), dabigatran, rivaroxaban, carbamazepine, alfentanil, fentanyl, sufentanil, aprepitant, cinacalcet, eletriptan (not to be used within
72 hr), bortezomib, busulfan, docetaxel, erlotinib, imatinib, paclitaxel, vincristine, vinblastine, indinavir saquinavir, maraviroc, fesoterodine, solifenacin, tolterodine, tadalafil, sildenafil and vardenafil (dosage adjustments may be necessary). - May ↑ levels and risk of toxicity with dasatinib, lapatinib, nilotinib, everolimus, sirolimus, and salmeterol; concurrent use not recommended
- May ↑ levels of aripiprazole; ↓ aripiprazole dose by 50%
- May alter the effectiveness of hormonal contraceptives (alternative method of contraception recommended).
- Drugs that ↑ gastric pH, including antacids, histamine H2 antagonists, didanosine (chewable tablets, because of buffer), and proton pump inhibitors↓ absorption (wait 2 hr before administration of ketoconazole).
- ↑risk of hepatotoxicity with other hepatotoxic agents, including alcohol.
- Disulfiram-like reaction may occur with alcohol.
- Rifampin, rifabutin, carbamazepine, phenytoin, or isoniazid may ↓ levels and effectiveness.
- Ritonavir may ↑ levels; should ↓ ketoconazole dose
- May ↓ absorption and effectiveness of theophylline.
