- concomitant medications including: amantadine, mycophenolate mofetil, and investigational HCV compounds, alfuzosin, alfentanil, ergot derivatives (dihydroergotamine/ergotamine/ergonovine/methylergonovine), meperidine, anti-arrhythmics (quinidine, flecainide, propafenone, amiodarone, bepridil), astemizole, terfenadine, buspirone, diazepam, estazolam, oral midazolam, triazolam, budesonide, domperidone, eletriptan, eplerenone, fluticasone, pimozide, salmeterol, calcium channel blockers (diltiazem, felodipine, nifedipine, nisoldipine, verapamil), cisapride, cyclosporine, sirolimus, systemic tacrolimus, atorvastatin, lovastatin, simvistatin, sildenafil, tadalafil, verdenafil, antibiotics (clarithromycin, erythromycin, telithromycin, troleandomycin), carbamazepine, Phenobarbital, phenytoin, nefazodone, St. Johns Wort, antifungals (fluconazole, itraconazole, ketoconazole, posaconazole, voriconazole), rifampin, rifabutin, aprepitant, cholestyramine, fluvoxamine, mifepreistone, modafinil, systemic dexamethasone. With the exception of St. Johns Wort, investigators may use their discretion on use of herbal and dietary supplements.