<qa>  What is the maximum time period for use of non-prescription drugs?12. Use of non-prescription drugs, including vitamins, herbal and dietary supplements including St Johns Wort within 7 days or 14 days if the drug is a potential enzyme inducer or 5 half-lives whichever is longer prior to the first dose of study drug, unless in the opinion of the Investigator and Medical Monitor the medication will not interfere with the study procedures or compromise subject safety. 