A face-to-face questionnaire survey on the use of multiple antipsychotics and the manifestation of side effects in outpatients with schizophrenia

Abstract

We investigated the use of multiple antipsychotics and the manifestation of side eŠects in outpatients with schizophrenia and compared the results of patients who received 1 antipsychotic (monotherapy) with those of patients who received more than 1 antipsychotic (multidrug therapy). To achieve this, we visited 8 community life-support centers and conducted a face-to-face questionnaire survey with 47 outpatients. Sixteen (34%) of these patients had received monotherapy and 31 (66%), multidrug therapy. Complaints involving the central nervous system, anticholinergic symptoms, metabolic symptoms (weight gain, increase in blood glucose, etc.), and extrapyramidal symptoms were seen across the patients. The average incidence of side eŠects was 2.2 per person in the monotherapy group and 4.8 in the multidrug-therapy group. The number of nonantipsychotic drugs used concomitantly in the monotherapy group was also smaller than that used in the multidrug-therapy group (2.3 and 5.0 per person, respectively). Further, we analyzed the 47 patients as described above; 20 patients received typical antipsychotics (TA group), 10 patients received atypical antipsychotics (AA group), and 17 patients received both typical and atypical antipsychotics (MIX group). The average incidence of side effects in the TA, AA, and MIX groups was 2.8, 3.2, and 5.5 per person, respectively, and the number of nonantipsychotic drugs used concomitantly was 2.2, 3.2, and 6.1, respectively. On the basis of our results, it can be suggested that monotherapy with an atypical antipsychotic can reduce both the number of nonantipsychotic drugs used concomitantly and the average incidence of side effects. © 2011 The Pharmaceutical Society of Japan.