Clozapine treatment in Denmark: concomitant psychotropic medication and hematologic monitoring in a system with liberal usage practices.

Abstract

BACKGROUND: Clozapine has been utilized in Denmark since the early 1970s. This study examines doses, concomitant psychotropics, and leukocyte counts. METHOD: All psychiatric hospitals in Denmark were asked for copies of all their clozapine monitoring forms, which were then personally reviewed by the authors. RESULTS: Forms from 656 patients were collected from 32 hospitals. The male/female ratio was 2/1; the median age, 38 years (range, 18-80). Thirty-five percent received concomitant antipsychotics, 28% benzodiazepines, 19% anticholinergics, 11% antidepressants, 8% antiepileptics, (carbamazepine, valproate, and phenobarbital), and 2% lithium. While there were no gender differences with respect to concurrent psychotropics, women received lower doses of clozapine than men (median dose, women 300 mg/day and men 400 mg/day, p < .02). Ten percent had had a neutrophil count < 2000/microL (3.2% < 1500/microL). Five percent had repeated neutrophil counts < 2000/microL (1.5% < 1500/microL). There were two cases of agranulocytosis; both patients fully recovered upon withdrawal of clozapine. Clozapine was discontinued because of hematologic abnormalities in only five other cases (0.8%). CONCLUSION: While use of concomitant psychotropics during clozapine treatment should be limited because of an increased risk of complications, a totally restrictive policy might deprive certain patients of the benefits of clozapine treatment. There appears to be a benign form of granulocytopenia that does not always necessitate discontinuation, provided there is close follow-up.