- The subjects is currently taking regular (or a course of) medication whether prescribed or not, including vitamins and herbal remedies, such as St John's Wort. Any concurrent medication will not be permitted for 48 hours before admission to the CPRU until the end of the study period (follow-up visit), unless in the opinion of the Investigator and the GSK Medical Monitor the medication will not interfere with the study procedures or compromise subject safety.