Trends of novel psychoactive substances (NPSs) and their fatal cases

The abuse of novel psychoactive substances (NPSs) has been increasing dramatically since the late 2000s worldwide. Furthermore, variations of synthetic cannabinoids and other NPSs have been appearing in the market recently. The number of newly identified NPSs in 2013 was 42 in Singapore, 37 in Korea, and 23 in Indonesia. Even though the kinds and amounts of NPSs are increasing sharply, toxicological information regarding NPSs is not available and hard to obtain. When compared to classical controlled drugs, there are only a few fatal cases and a limited number of data in terms of metabolism and toxicity of NPSs. However there have been fatal cases of NPSs reported continuously in the USA, Europe, Japan and other countries, but not in Korea. Therefore, in this study, the fatal concentrations of NPSs have been reviewed through papers to predict the unexpected side effects or toxicological effects of NPSs. The blood concentrations of synthetic cannabinoids, synthetic cathinones and others in fatal cases are presented. JWH-018, JWH-073, MAM-2201, NNEI, MDPV, mephedrone, methylone, alpha-PVP, PV9, 25I-NBOMe, PMMA and methoxetamine were substances targeted. The fatal NPS cases will be of great help for forensic toxicologists in the research of the metabolism and toxicity of NPSs, and will also aid in establishing analytical methods for detecting NPSs in biological fluids.