Intoxications in the STRIDA project involving a panorama of psychostimulant pyrovalerone derivatives, MDPV copycats

Context: An increasing number of new psychoactive substances (NPS) of different chemical classes have become available through marketing and sale over the Internet. This report from the Swedish STRIDA project presents the prevalence, laboratory results, and clinical features in intoxications involving 11 stimulant pyrovalerone NPS derivatives over a 5-year period. Study design: Case series of consecutive patients with admitted or suspected intake of NPS presenting to Swedish hospitals for emergency treatment from January 2011 to March 2016. Patients and method: Blood and urine samples were collected from intoxicated patients presenting to hospitals all over Sweden. Analyses of NPS and other drugs of abuse were performed by immunochemical and liquid chromatography-mass spectrometry multi-component methods. Clinical data were collected during consultation with the Swedish Poisons Information Centre (PIC), and retrieved from medical records. The study involved analytically confirmed cases with 11 pyrovalerone drugs. Results: During the study period, 114 intoxications were detected that involved any of 11 new pyrovalerone drugs. In addition to these new pyrovalerone derivatives, 3,4-methylenedioxypyrovalerone (MDPV) was detected in 17 of the cases and alpha-pyrrolidinovalerophenone (alpha-PVP) in 45 cases. Identification was made according to forensic standards and comprised the following substances: 4F-alpha-PVP, alpha-PHP, PV8, 4Me-PPP, alpha-PBP, 4F-PV8, alpha-PPP, MDPHP, alpha-PVT, 4Cl-alpha-PVP, and 4F-alpha-PHP. The three most frequently detected drugs were alpha-PBP, MDPHP, and 4F-alpha-PVP. The age range of patients was 16-66 (median 30) years and 84% were males. The substance concentrations in urine and serum were highly variable, ranging from 1 ng/mL to 300 mu g/mL. Poly-drug use was common with only 8 of 114 cases (7%) involving one pyrovalerone drug. The additional substances comprised other NPS and classical psychoactive drugs. The patients showed a variety of clinical signs; agitation, delirium, hallucinations, excessive motor activity, seizures, tachycardia, hypertension, and/or hyperthermia. Conclusions: In analytically confirmed NPS-related intoxications, 11 new pyrovalerone derivatives in addition to MDPV and alpha-PVP were found. The clinical features were consistent with a sympathomimetic toxidrome, but the urine and serum concentrations were highly variable. The results demonstrated that many novel pyrovalerone stimulants were introduced on the recreational NPS drugs market. Analytical investigations were necessary to obtain this information.