THE ANTI-PARKINSONIAN DRUGS IN ANTIPSYCHOTIC TREATMENT - A COMPARATIVE-STUDY OF PROGRESSIVE AND ABRUPT WITHDRAWAL

The systematic and long term association of anti-parkinsonian drugs to neuroleptics is questioned by many authors because of their side effects and their toxicomanogenous risks whereas their efficiency in extrapyramidal effects of prophylaxys is not certain. This work aims at evaluating the interest of prescribing long term parkisonian drugs in association with neuroleptics. The study centered on 101 psychotic patients treated with neuroleptics, and followed on an ambulatory bases. 97 % of this patients systematically received antiparkinsonian drugs. Extrapyramidal symptoms of varied intensity have noted far 61 % of patients. The authors have compared, in double blind, the effects of the progressive and abrupt withdrawal of anti-parkinsonian drugs for 37 patients among the 101. These patients have been regularly treated for at least 6 months by neuroleptics (fluphenazine or pipothiazine) in association with trihexyphenidyle. They were randomly divided into 3 groups, and statified by sex and type of neuroleptic. For group I, composed of 13 patients, trihexyphenidyle is abruptly withdrawn and replaced by a placebo. For group II, composed of 11 patients, withdrawal is progressive for 2 weeks, trihexyphenidyle being replaced by a placebo. Group III, composed of 13 patients, is a sample group which went on receiving trihexyphenidyle. The results of this study showed that within the brutal withdrawal group (group I), 10 patients over 13 needed trihexyphenidyle again, whereas only 3 patients over 11 needed it in the progressive withdrawal group (group II). In the sample group (group III), one patient over 13 showed extrapyramidal symptoms, necessitating his leaving school. The global chi(2) is significant with p < 0.001. The Fisher test shows a significant difference between group I and group II (p < 0.01). However, there is no significant difference between progressive placebo group and the sample group. Consequently abrupt withdrawal seems the main risk factor of the appearance of extrapyramidal symptoms. Systematic treatment by anti-parkinsonian drugs seems to be useless, even dangerous and they have to be used in case extrapyramidal signs appear and become serious. Their prescription at small doses and for a limited period minimeses the risk of pharmacodependence. Their withdrawal has to be progressive.