First reported case in the UK of acute prolonged neuropsychiatric toxicity associated with analytically confirmed recreational use of phenazepam.

There is increasing evidence from around Europe of the availability and misuse of long-acting benzodiazepines such as phenazepam. There is little information on the acute toxicity of these compounds; we describe here a case of analytically confirmed phenazepam-related acute toxicity. A 42-year-old man with no previous medical or psychiatric history was brought to the Emergency Department by his friends because he had developed prolonged ongoing confusion and disorientation following use of up to three different "legal high" powders. There was no obvious medical cause for this acute confusion and disorientation. His symptoms continued for approximately 60 h after suspected use. Subsequent toxicological analysis of a serum sample confirmed use of phenazepam (concentration 0.49 mg/L); no other drugs were detected during an extensive analytical screening. This is the second case of analytically confirmed acute toxicity related to phenazepam in Europe. This adds to the scant published information on the acute toxicity of this drug, and will provide healthcare and legislative authorities with further information on which to base advice and consideration of the need for its control.