- Treatment with any of the following medications within 15 days of starting study drug, or anticipated to need, during the course of the study: Etravirine (unless co-administered with LPV/RTV or DRV/RTV), rifampin, rifabutin, phenytoin, phenobarbital, barbiturates, glucocorticoids, modafinil, oxcarbazepine, pioglitazone, troglitazone, carbamazepine, St. Johns wort