Drug-induced Behavioral Changes Research Articles

Relevance of drug-induced extrapyramidal reactions to behavioral changes during neuroleptic treatment I. Treatment with trifluoperazine singly and in combination with trihexyphenidyl

This study was performed in order to determine whether or not a relationship exists between the therapeutic effectiveness of a neuroleptic agent and its drug-induced extrapyramidal reactions. Furthermore, the effects of anti-parkinson medication on drug-induced behavioral changes and extrapyramidal signs were examined. In addition it was desired to ascertain if the mutually antagonistic effects of these two drugs exerted at the level of the extrapyramidal system also applied to behavioral parameters. In order to do so trifluoperazine was taken as the agent which is powerful in affecting behavior as well as evoking extrapyramidal manifestations and the trihexyphenidyl was employed as the antiparkinson drug. For this purpose 26 schizophrenic patients consisting of equal numbers of males and females were given trifluoperazine singly or in combination with trihexyphenidyl. The behavioral alterations were evaluated in psychiatric interviews and at the same time extrapyramidal symptoms were determined by handwriting analysis and neurological examinations. It was found that the optimal therapeutic effect of the neuroleptic drug was achieved when only very mild extrapyramidal symptoms occurred and especially when changes in handwriting only were apparent, while with increasing severity of the neurological reactions the behavior of the patients became progressively worse. The most severe anxiety was observed with marked akathisia (during which the patient could not sit still because of an irresistible urge to walk) and grave dyskinesia characterized by involuntary movements and spastic contractions. Trihexyphenidyl did not interfere with the behavioral improvement achieved by the neuroleptic drugs. On the contrary, the overall therapeutic effect was superior to that observed with trifluoperazine alone while at the same time extrapyramidal symptoms were reduced in intensity. It is concluded from the results of this study that in general the optimal improvement of behavior during neuroleptic treatment occurred when very slight extrapyramidal symptoms appeared and especially when they were manifested only in handwriting. It is therefore suggested that when marked neurological reactions occur the dose of the neuroleptic drug should be reduced and/or an antiparkinson agent be administered.