Spice and all things nasty: the challenge of synthetic cannabinoids

The Psychoactive Substances Act 2016, which came into force in May, signals a new approach to drug controls in the UK. For the first time, the basis for illegality is pharmacological action rather than chemical structure. The act made it illegal to produce or supply “spice” or synthetic cannabinoids and to possess them in a custodial setting.

Synthetic cannabinoids are a group of structurally unrelated compounds that act at the cannabinoid receptors CB1 and CB2. Spice is the commonest UK term, but there are more than 500 other street names, including black mamba and annihilation.1 The chemicals are synthesised in a laboratory, dissolved in a solvent, then sprayed onto plant material, which is smoked or, less commonly, taken orally or injected. Previous attempts to ban synthetic cannabinoids failed because compounds with novel structures could be produced quickly. The clinical challenge of these substances mirrors the legislative challenge in that the severity of harms demands a substantial response while their chemical variety makes monitoring …