 - Unable to refrain from prescription or non-prescription drugs, including agents active in the central nervous system, 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 medication and throughout the study, unless in the opinion of the Investigator andor GSK Medical Monitor if needed the medication will not interfere with the study procedures or compromise subject safety. 