Agranulocytosis and significant leucopenia with neuroleptic drugs: results from the AMÜP program

Abstract

In the Federal Republic of Germany adverse drug reactions (ADR) have been continously assessed at the departments of Psychiatry of Berlin and Munich since May 1979. About 13000 neuroleptic-treated inpatients were monitored until August 1988. Approximately 1100 patients were exposed to clozapine, 6800 to haloperidol and 6000 to perazine, the two most frequently used neuroleptic drugs. In this 9-year period seven cases of agranulocytosis were observed, all in women. One case occurred with clozapine in monotherapy, the other six with perazine, three times in monotherapy, once in combination with trimethoprim/sulfamethoxazole and in one case each in combination with tricyclic antidepressants. Significant leucopenia (≤3000/mm³) was observed in an additional eight cases. On four occassions each butyrophenones (twice in combination with TCA) and tricyclic neuroleptics (once in combination with TMS) were involved. The number of exposed patients per drug is too small for calculation of statistically valid incidence rates, especially in view of the frequent polypharmacy. The course of agranulocytosis was benign in all seven cases and required no other treatment than drug withdrawal in three cases. The early detection by regular WBCs is supposed to be mainly responsible for this and is therefore recommended at weekly intervals. This measure of safety appears most important for all medium potency tricyclic neuroleptics. As to treatment of agranulocytosis, additional measures (antibiotics, intensive medical care) depend upon the severity of the clinical picture.