- Use of any of the following: Any concomitant medication including oral contraceptive hormones. Subjects who have received any prescribed or non-prescribed (over-the-counter [OTC]) systemic medication, topical medications, or herbal supplements within 14 days from Day 1. St. John's Wort (hypericin) must not have been taken for at least 30 days prior to Period 1, Day 1. Any drugs, foods or substances known to be strong inhibitors or strong inducers of CYP enzymes (also known as cytochrome P450 enzymes); especially CYP 1A2, or Pgp within 30 days prior to Period 1, Day 1