- Use of prescription or non-prescription drugs, including CYP3A4 inhibitors and inducers, vitamins, herbal and dietary supplements (including St John's Wort) from 14 days before screening until the follow-up visit, unless in the opinion of the Investigator and GSK Medical Monitor the medication will not interfere with the study procedures or compromise subject safety. Hormone Replacement Therapy (HRT) is permitted for post-menopausal females.