"Few reports on the toxicity of synthetic cathinones exist to date. Much of the current knowledge on health-related effects comes from user reports and clinical observations. Further research is needed to provide evidence of short and long-term health risks and the addiction potential associated with the use of these substances.
"Whereas cardiac, psychiatric, and neurological signs are some of the adverse effects reported by synthetic cathinone users, agitation, ranging from mild agitation to severe psychosis, is the most common symptom identified from medical observations.25 Studies of patients under the apparent influence of mephedrone have also shown that synthetic cathinones present similar sympathomimetic effects (including tachycardia and hypertension as well as psychoactive effects) to similar amphetamine derivatives.26 In a student survey, more than half of those who had taken mephedrone reported adverse effects associated with the central nervous system, nasal/respiratory system and cardiovascular system.27 The first fatality related to the sole use of mephedrone, confirmed by toxicological analysis, was reported in Sweden in 2008.28 Most fatalities associated with the use of mephedrone involved the use of other substances.29 Deaths associated with the use of other synthetic cathinones include two deaths related to methedrone30 and two other deaths related to butylone.31
"The Finnish Poisons Information Centre reported 33 calls regarding exposures to MDPV during the period of January 2008 to October 2009. Post mortem toxicological analysis confirmed 6 deaths related to MDPV between 2009 and 2010, although in most of the cases the presence of other drugs was also detected.32 A report from the United States provided details on the case of 35 patients who visited an Emergency Department over a 3-month-period after ingesting, inhaling or injecting substances sold as ‘bath salts’ and asserted that these products could contain stimulant compounds such as MDPV or mephedrone. One person was dead upon arrival at the emergency department. The toxicological analysis revealed a high level of MDPV, along with cannabis and prescription drugs, but the autopsy results revealed MDPV toxicity to be the primary factor contributing to death.33"
UN Office on Drugs and Crime, "The Challenge of New Psychoactive Substances: A Report from the Global SMART Programme" (Vienna, Austria: UNODC Laboratory and Scientific Section, March 2013), p. 7.