- Treatment with any prescription or non-prescription drugs (including vitamins, herbal and dietary supplements, as well as grapefruit-containing products) within 7 days or 5 half-lives (whichever is longer) prior to first dose of study medication and until the end of the study. Treatment with any CYP2D6 inhibitors such as but not limited to quinidine, fluoxetine, paroxetine, duloxetine, and terbinofine at least 14 days or 5 half-lives (whichever is longer) prior to Day 1 of Session 1 and until the end of the study.