9. Subjects who need to take CYP3A4 inducers, such as phenobarbital, dexamethasone, carbamazepine,phenytoin, rifampicin, or non-nucleoside reverse transcriptase inhibitors (e.g., efavirenz, nevirapine,etravirine) will be excluded. Prior use of these agents is acceptable, as long as they are stopped at least a week prior to study entry.