- Use of prescription or non-prescription medicines, including over-the-counter remedies, vitamins, herbal and dietary supplements (including St John's Wort) within 7 days (or 14 days if the drug is a potential enzyme inducer) or 5 half-lives (whichever is longer) before the first dose of study medication, unless, in the opinion of the Investigator and Sponsor, the medication will not interfere with the study procedures or compromise subject safety.