Anticholinergic drugs are abused

There is a need for the general practitioner to be aware of the growing use of anticholinergics , such as benzhexol [trihexphenidyl), benztropine mesylate and biperiden, to escape from , or blunt the effect of, daily existence. In two studies the abuse of anticholinergics as euphoric or stimulant agents was investigated . Firstly 27/154 patients admitted to a ward for behaviourally disturbed patients were found to be trihexphenidyl abusers . There was adequate data on 21 of these patients and most had antisocial personalities or schizophrenia and all were multiple drug abusers . Benzhexol was abused in doses of 15-60mg taken orally, either daily or every 2-3 weeks. In the second study which examined 28 anticholinergic drug abusers over 2 years, 15/28 also abused other drugs, 27 had been prescribed neuroleptic drugs and 21 had a diagnosis of schizophrenia.

It is suggested that patients who request neuroleptic drugs for worsening extrapyramidal symptoms should be carefully examined, and that ant icholinergic drug abuse be considered as a diagnosis for patients presenting with confusion, visual hallucinations, tachycardia, thirst or dizziness. Further, the investigators determined that anticholinergic drug abusers are not necessarily psychiatric patients who have been exposed to neuro/eptics, but the general opinion of patients questioned was that it is not difficult to obtain prescriptions for benzhexol from doctors. Thus, prescriptions of anticholinergics should be kept to the minimal effective dosage for as short a time as possible. International Drug Therapy Newsletter 20: 1-2 (Jan 1985)