1 Guy's and St Thomas' NHS Foundation Trust, Department of Clinical Pharmacology, St Thomas' Hospital, London, SE1 7EH.
2 Quality Assurance Department, Pharmacy, Guy's and St. Thomas' NHS Foundation Trust, St Thomas' Hospital, London, SE1 7EH.
3 Department of Ageing & Health, Guy's and St. Thomas' NHS Foundation Trust, St Thomas' Hospital, London, SE1 7EH.
4 King's College London British Heart Foundation Centre, Cardiovascular Division, Department of Clinical Pharmacology, St Thomas' Hospital, London, SE1 7EH.
5 Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trust, St Thomas' Hospital, London, SE1 7EH, UK.