Overview Efavirenz and Ritonavir on Human Brain P-Glycoprotein Status: Completed Trial end date: 2016-08-01 Target enrollment: Participant gender: Summary To determine the effects of ritonavir and efavirenz on the activity of P-glycoprotein in human brain. Phase: Phase 1/Phase 2 Details Lead Sponsor: Washington University School of MedicineTreatments: AntidiarrhealsEfavirenzKrestinLoperamideRitonavir