Prophylactic laxatives in clozapine-treated patients: a long road ahead

Introduction: In recent years, higher rates of mortality have been recorded from clozapine-induced gastrointestinal hypomotility than from agranulocytosis. Still, this adverse reaction does not receive enough attention. Some authors recommend prophylactic laxatives for every clozapine-treated patient but little information exists about laxative use in this patient cohort. Methods: To conduct this study we identified all patients treated with clozapine of Araba, Northern Spain. To identify eligible patients we used PRESBIDE which contains all outpatient prescription medications funded or not by the drug benefit plan. We measured the medication possession ratio (MPR) as an indirect measure of adherence both for clozapine and other medications including laxatives. Results: A total of 217 clozapine-treated outpatients were included. Mean age was almost 47 years, and about three-quarters were male. The most frequent reason for clozapine use was schizophrenia, and mean duration of clozapine treatment was 4.5 years. Six of the 217 patients (2.7 %) had a laxative prescription, with a mean MPR of 8.4% in this therapeutic class. Conclusions: Laxatives were under-utilized and adherence was poor. We recommend healthcare professionals educate clozapine-treated patients and their families as to the risks of gastrointestinal hypomotility, offer prophylactic laxatives and advise patients to take them as prescribed.