Misuse of Trihexyphenidyl (Artane) on Réunion Island

Abstract Background Trihexyphenidyl (THP) is an anticholinergic drug misused to procure hallucination, sedation, and anxiolysis. The aim of this cohort was to show and describe, within a public health risk management policy, the risks of a long-standing but relatively unknown addiction: THP addiction. Methods On Réunion island, a cohort with systematic data collection has been set up by addictologists working in the Centres for Addiction Prevention and Treatment, in the university hospital, and in general practices who have active lists of patients misusing THP. Data collection included socioeconomic data and clinical data concerning addiction. Results This cohort included 69 patients during November 2016. The average age of the patients was 36 years; 97% were men; 93% had living accommodation but only 32 % were employed. In this cohort drug administration was exclusively oral. The most common reasons for use were anxiolytic (46%), stimulation (26%), and sedation (10%), the main effects described were dyskinesia and behavioral disorders. Over half (61%) of the patients reported a coaddiction, mainly to benzodiazepines, cannabis, tobacco, alcohol, and buprenorphine. Conclusions This cohort describing the clinical characteristics of 69 patients is the largest cohort studied for THP addiction. Patients from the Centres for Addiction Prevention and Treatment were the youngest and most recently addicted, whereas general practice patients had been addicted for longer and were more socially integrated. This clinical description of THP addiction therefore enables us to identify the patients who are the most at risk, to set up an adapted care protocol.