Investigation of drug products received for analysis in the Swedish STRIDA project on new psychoactive substances

The web-based open sale of unregulated new psychoactive substances (NPS) has shown a steady increase over the past years. Analysis of drug products sold as NPS is useful to confirm the true chemical contents, for comparison with the substances detected in corresponding body fluids, but also to study drug trends. This work describes the examination of 251 drug products that were randomly submitted for analysis in 173 cases of suspected NPS-related intoxications in the Swedish STRIDA project in 2010–2015. Of the products, 39% were powders/crystals, 32% tablets/capsules, 16% herbal materials, 8% liquids, 1% blotters, and 4% others. The analysis involved tandem mass spectrometry and nuclear magnetic resonance spectroscopy. In 88 products (35%), classical psychoactive substances, prescription pharmaceuticals, dietary supplements, or doping agents were found; however, in none of these cases, an NPS-related intoxication had been indicated from product markings or patient self-reports. Another 12 products tested negative for psychoactive substances. The remaining 151 products contained 86 different NPS (30% contained ≥2 substances). In 104 drug products, a specific NPS ingredient were indicated based on labelling (69%) or patient self-report; in 92 cases this was also analytically confirmed to be correct. Overall, the NPS products submitted for analysis in the STRIDA project showed a high degree of consistency between suspected and actual content (88%). The results of related urine and/or blood analysis further demonstrated that the patients commonly (89%) tested positive for the indicated NPS, but also revealed that polysubstance intoxication was common (83%), indicating use of additional drug products.