R(-) methadone AUC ↔ 1.06 (0.99-1.13) R(-) methadone Cmin ↔ 1.10 (1.02-1.19) R(-) methadone Cmax ↔ 1.02 (0.96-1.09) S(+) methadone AUC ↔ 0.89 (0.82-0.96) S(+) methadone Cmin ↔ 0.89 (0.81-0.98) S(+) methadone Cmax ↔ 0.89 (0.83-0.97) etravirine AUC ↔ a etravirine Cmin ↔ a etravirine Cmax ↔ a