Although anticholinergic drugs have established their place in the treatment of neuroleptic-induced extrapyramidal symptoms (EPS) (see Part I), treatment with anticholinergic drugs is not without its own inherent risks. It can result in disabling central as well as peripheral anticholinergic side effects. This aspect has assumed more importance with the recognition that antipsychotic medications are being used at greater doses than before (Kane & Lieberman, 1987) with consequent increase in the dose of anticholinergic medication. In addition to having side effects of their own, concomitant use of anticholinergic drugs and neuroleptics may also result in potentially significant interactions (Watski & Salzman, 1991) and these drugs have also been recognised as potential substances of misuse and abuse (Land et al, 1991).. Moreover, the prescription of anticholinergic agents has also been considered a possible risk factor for tardive dyskinesia (Klawans & Rubovitz, 1974; Kane & Smith, 1982; Griel et al, 1984; Barnes, 1988) a movement disorder associated with long-term neuroleptic treatment. The above considerations have prompted several studies on the efficacy, need and effects of withdrawal of anticholinergics in an effort to get some clear answers about the most effective use of these drugs. This article discusses the evidence from the literature on some benefits and limitations of using anticholinergic drugs for the treatment of neuroleptic-induced EPS.
Individual requirements for anticholinergic drugs as well as tolerance to anticholinergic-induced side effects differ greatly. For example, deaths have occurred following atropine 100mg whilst recovery has been reported after 1 gm (Parkes, 1981). Several factors should be considered when anticholinergic drug treatment is initiated