Misuse of anticholinergic medications: a systematic review.

Abstract

Background: Over the last decade misuse and diversion of medications appeared to be increasingly concerning phenomena, including a range of different molecules. As current knowledge on the abuse of centrally acting anticholinergics is limited, the aim of the present study was to review the relevant published data, focusing on the following molecules: benztropine, biperiden, scopolamine, orphenadrine, and benzhexol/trihexyphenidyl (THP). Methods: A systematic literature review was carried out using Pubmed, Scopus and Web of Science databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Research methods were registered on PROSPERO (CRD42021257293). Results: Some 48 articles, including case reports, surveys, and retrospective case series analyses, were here included. Most articles focussed on benzhexol/THP (n = 25), and benztropine (n = 4). The routes of administration was mostly oral, and macrodoses together concomitant illicit drugs, e.g. cocaine, have been recorded. Toxidromes included both psysical (e.g. tachycardia, tachypnoea, dilatated pupils, dry skin, urinary retention, ataxia, etc.) and psychiatric symptoms (e.g. anxiety, agitation, delirium, etc.). Fatal outcomes were very rare, but reported. Conclusion: Results from the present study showed that anticholinergic misusing issues are both widespread worldwide and popular. Considering the potential adverse effects associated, healthcare professionals should be vigilant and monitor eventual misusing issues.