 - Are taking strong cytochrome P cytochrome P450, family 3, subfamily A, polypeptide 4 CYP3A4 inhibitors e.g., clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, posaconazole, ritonavir, saquinavir, telithromycin, voriconazole or strong CYP3A4 inducers e.g., carbamazepine, phenobarbital, phenytoin, rifampin, St. Johns wortHypericum perforatum 