ANTICHOLINERGIC DRUG-ABUSE AND MISUSE - EPIDEMIOLOGY AND THERAPEUTIC IMPLICATIONS

Abuse of the centrally acting anticholinergic agents is a phenomenon o ccasionally reported in the medical literature. Anticholinergics, most often used in psychiatry to treat antipsychotic-induced extrapyramida l symptoms, are also used by some patients for their mood altering and psychedelic effects. The changes in sensorium can range from mild eup horia and increased sociability to hallucinations and toxic psychosis. In this article, we have reviewed 110 cases of reported anticholinerg ic abuse and identified 3 distinct groups of abusers: (i) those indivi duals who have no valid medical need for the medication and consume it only for its mind-altering effects; (ii) those with a valid indicatio n for the use of anticholinergics who also abuse the agents for their mind-altering effects; and (iii) those who have an appropriate medical indication for the agents and appear to be using anticholinergics to relieve chronic or subclinical extrapyramidal symptoms, depression or negative schizophrenic symptoms. True abusers (i.e. those individuals in the first 2 groups) can be recognised because they feign extrapyram idal symptoms, repeatedly 'lose' their medications or request unnecess ary dose increases. In order to reduce the risk of abuse, exposure to anticholinergics should be minimised in patients at risk. Patients who are reluctant to have their anticholinergics discontinued should be c arefully evaluated to identify potential risks and benefits of continu ed use before prolonged therapy is instituted. Anticholinergics should not be abruptly discontinued, but instead tapered over a 2-week perio d in patients receiving high doses or long term treatment.