"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"

"Street names for some phenethylamines include ‘Europa’ for 2C-E; ‘4-FMP’, ‘para-fluoroamphetamine’, ‘RDJ’ for 4-FA; and ‘4-MMA’, ‘Methyl-MA’ for PMMA. Phenethylamines are usually available in form of pills, but FLY compounds are commonly sold in powder form, while oral doses (on a slip of blotter paper) are usually available for ‘D substances’. Ingestion is the most common route of administration of phenethylamines."

Piperazines

"Piperazines have been described as ‘failed pharmaceuticals’, as some had been evaluated as potential therapeutic agents by pharmaceutical companies but never brought to the market.⁵⁵ While the best known piperazine that has been used as a new psychoactive substance is 1-benzylpiperazine (BZP), during the last decade other compounds such as 1-(3-chlorophenyl) piperazine (mCPP), 1-(3-trifluoromethylphenyl) piperazine (TFMPP) and, to a lesser extent, 1-Benzyl-4-methyl-piperazine (MBZP) and 1-(4-Fluorophenyl)piperazine (pFPP) have been identified on the market.⁵⁶
"BZP was initially developed as a potential antidepressant drug, but was found to have similar properties to amphetamine and therefore liable to abuse. In the 1980s, it was used in Hungary to manufacture piberaline, a substance marketed as an antidepressant, but later withdrawn.57 In the late 1990s, BZP emerged in New Zealand as a ‘legal alternative’ for MDMA and methamphetamine.⁵⁸ In Europe, its use was first reported in Sweden in 1999, but it only became widespread as a NPS from 2004 onwards until controls over the substance were introduced in 2008, in the European Union.⁵⁹
"MCPP, reportedly more widespread than BZP in some regions of the world,⁶⁰ was developed during the late 1970s and is used as an intermediate in the manufacture of several antidepressants, e.g. trazodone and nefazodone.⁶¹ TFMPP is almost always seen in combination with BZP to produce the entactogenic⁶² effects of MDMA.⁶³
"Neither BZP nor any other piperazines are under international control, although several (BZP, TFMPP, mCPP, MDBP) were pre-reviewed by the WHO Expert Committee on Drug Dependence in 2012. Several countries have introduced national control measures over piperazines."

"Information on the toxicological aspects of many piperazines listed in this group remain limited. Further research is required to provide evidence on short and long term health-effects associated with the use of these substances. Current knowledge comes from user reports, studies in animals, limited human studies, and clinical observations.
"Piperazines have been found to act as stimulants as a result of dopaminergic, noradrenergic, and predominantly serotoninergic effects produced in the brain. BZP produces toxic effects similar to amphetamine and other sympathomimetics, although, according to animal studies, its effects are less potent than amphetamine, methamphetamine and MDMA.⁶⁶ TFMPP, used in conjunction with BZP, has been reported to produce some of the effects of MDMA, but with a lower potency,⁶⁷ while mCPP has been indicated to produce similar stimulant and hallucinogenic effects as MDMA.⁶⁸
"In New Zealand, toxic seizures and respiratory acidosis after the use of BZP alone or in conjunction with other drugs were reported from three patients.⁶⁹ Another study of 61 patients reported toxic effects of BZP, with two cases presenting life-threatening toxicity.⁷⁰ Hyperthermia, rhabdomyolysis and renal failure associated with BZP ingestion have also been reported.⁷¹ In the United Kingdom, self-terminating grand mal seizures72 after the use of BZP have also been reported.⁷³
"Between 2004 and 2008, six fatal cases involving piperazines use were reported in Europe. Two of the cases involved the use of BZP in conjunction with TFMPP and none referred to the use of piperazines alone.⁷⁴ BZP and TFMPP were also associated with 19 fatalities between 2007 and 2010.⁷⁵ While reported effects of mCPP include the serotonin syndrome, no fatal poisonings from mCPP have been reported so far.⁷⁶ Similarly, toxic effects from the use of TFMPP alone have not been documented.⁷⁷"