1 Department of Anesthesiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
2 Ramathibodi Poison Center, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
3 Division of Clinical Pharmacology and Toxicology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
4 Society and Health Institute, Health Technical Office, Office of the Permanent Secretary, Ministry of Public Health, Thailand.
5 Pain Research, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, United Kingdom.
6 Department of Pharmacology, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand.