Intolerance to neuroleptic drugs: the art of avoiding extrapyramidal syndromes

Summary

Akathisia, dystonia, dyskinesia and parkinsonism, the four main categories of neuroleptic-induced extrapyramidal syndromes (EPS), represent major disadvantages in antipsychotic therapy. In vulnerable patients, acute EPS may progress into potentially irreversible forms such as tardive dystonia and tardive dyskinesia. In the psychiatric clinic, these EPS are often insufficiently recognised or permitted to exist without treatment. In order to ensure a better EPS diagnosis, a simple examination procedure is described. EPS rating scales may serve as an aid in this process. Guidelines are given to prevent and treat EPS. Thus, EPS are best prevented by a course of neuroleptic medication involving as little antidopaminergic D₂ effect as possible, including the use of the lowest effective dose (sometimes obtained by addition of a benzodiazepine or carbamazepine) and with antipsychotic drugs which produce low D₂ receptor blockade. Treating EPS also consists of using the lowest effective dose and antipsychotics with a low D₂ dopamine receptor occupancy. At present, clozapine is the only drug that produces antipsychotic benefits at doses that cause far less D₂ receptor antagonism in the basal ganglia of the brain than that seen with standard neuroleptics; however, newer drugs, such as olanzepine, seroquel and sertindole, are on the way.