Novel psychoactive substance

Editor – We read with interest the article entitled ‘Acute neurological consequences of novel psychoactive substance use: a retrospective review in a large UK hospital’ by Tanti et al.¹ The team have effectively highlighted the high rates of psychiatric comorbidity, unemployment, homelessness and incarceration in this vulnerable group in society. However, the paper may have benefitted from involvement of a clinical or analytical toxicologist to prevent several inaccuracies. Lack of analytical confirmation in any patient is a major limitation; self-reporting of substances of abuse (especially novel psychoactive substances (NPS)) is known to be unreliable. It is misleading to state ‘unfortunately, drug screens do not detect novel psychoactive substances’ since, while basic point-of-care immunoassay-based tests will not detect NPS, analytical confirmation of NPS is now available in several NHS laboratories. The authors refer to testing being possible only ‘by specialised techniques like gas chromatography’; most NHS laboratories have moved away from gas chromatography to ultra-performance liquid chromatography (UPLC), tandem mass spectrometry (MS/MS) or time of flight (TOF) for NPS detection.

The abstract states ‘Synthetic cathinone users presented with psychiatric disturbance or seizures (55%)’; this percentage does not correlate with the values in Table 2. There are certain errors of nomenclature in the article. The authors refer to ‘THC receptors’ while the correct terminology is cannabinoid (CB₁ and CB₂) receptors. Synthetic cannabinoids have been abbreviated in the text to SCs, yet ‘SCRAs’ (synthetic cannabinoid receptor agonists) is the widely accepted acronym used.

Finally, there seems to be some confusion regarding the provision of toxicology guidance and advice to the NHS. The authors refer to ‘poisons services like TOXBASE’; the National Poisons Information Service (NPIS) is a service commissioned by the UK Health Security Agency (formerly Public Health England); TOXBASE is the primary clinical toxicology information database written by the NPIS.