S Hiom1, G K Patel2, R G Newcombe3, S Khot4, C Martin5. 1. Research and Development, St. Marys Pharmaceutical Unit, Cardiff and Vale University Health Board, Cardiff, U.K.. sarah.hiom@wales.nhs.uk. 2. Department of Dermatology, Prince Philip Hospital, Hywel Dda University Health Board, Carmarthenshire, U.K. 3. Cochrane Institute of Primary Care and Public Health, School of Medicine, Cardiff University, Cardiff, U.K. 4. Complex Pain Clinic, Department of Anaesthesia, Intensive Care and Pain Medicine; Cardiff and Vale University Health Board, Cardiff, U.K. 5. Research Associate, St Mary's Pharmaceutical Unit, Cardiff and Vale University Health Board, Cardiff, U.K.