Effect of anticholinergics on tardive dyskinesia. A controlled discontinuation study

In a double-blind, placebo-controlled study, ten chronic schizophrenic patients with pronounced symptoms of tardive dyskinesia (TD) were withdrawn from anticholinergic medication. All patients had previously been under long-term treatment with neuroleptics and anticholinergics for at least two years. The rating-scales used were the AIMS, our own TD Scale, and the Simpson-Angus scale for extra-pyramidal side-effects. The severity of TD decreased significantly in nine patients with in two weeks; this improvement, most pronounced in the oral region (P less than .001), persisted during a six-week placebo period. There was a slight increase in parkinsonian symptoms (P less than .05), which was not a prerequisite for improvement in TD. Hence, discontinuation of anticholinergic medication is a possible therapeutic approach in patients with TD.