The synthetic cathinone -pyrrolidinovalerophenone (-PVP): pharmacokinetic and pharmacodynamic clinical and forensic aspects

New psychoactive substances (NPS), often referred as legal highs' or designer drugs', are derivatives and analogs of existing psychoactive drugs that are introduced in the recreational market to circumvent existing legislation on drugs of abuse. This work aims to review the state-of-the-art regarding chemical, molecular pharmacology, and in vitro and in vivo data on toxicokinetics of the potent synthetic cathinone -pyrrolidinovalerophenone (-PVP or flakka or zombie drug). Chemical, pharmacological, toxicological, and clinical effects of -PVP were searched in PubMed (U.S. National Library of Medicine) and governmental websites without limitation of the period. -PVP is a wide spread and easy to get special type of synthetic cathinone with seemingly powerful cocaine-like stimulant effects, high brain penetration, high liability for abuse and with increased risk of adverse effects such as tachycardia, agitation, hypertension, hallucinations, delirium, mydriasis, self-injury, aggressive behavior, and suicidal ideations. -PVP undergoes extensive metabolism via different pathways and the -PVP itself or its metabolites -hydroxy--PVP and -PVP lactam represent the main targets for toxicological analysis in urine. There is a limited knowledge regarding the short- and long-term effects of -PVP and metabolites, and pharmacogenetic influence, hence further clinical and forensic toxicological studies are required. Moreover, since -PVP cannot be detected with classic routine analysis procedures, statements on the frequency of their consumption cannot be made.