The aim of this study was to investigate factors associated with concomitant
laxative use among
schizophrenia patients discharged on second-generation
antipsychotics (SGAs) at two large psychiatric hospitals in Taiwan. Patients with
schizophrenia who were discharged between 2006 and 2017 and received SGA monotherapy at discharge were included in the analysis. Multivariate logistic regression was used to identify factors associated with regular
laxative use at discharge. Multivariate Cox regression was used to determine the effect of
laxative use at discharge on time to
rehospitalization within one year. The Cochran-Armitage trend test was used to evaluate whether significant time trends existed for rates of
laxative use at discharge during the study period. Among patients discharged on SGAs (n = 11,861), 3,336 (28.1%) also received concomitant laxatives. Advanced age and higher
antipsychotic or
anticholinergic doses were found to be associated with an increase in
laxative use. Among SGAs,
clozapine was associated with the highest rate of
laxative use, followed by
zotepine,
quetiapine,
olanzapine and
risperidone. Additionally,
risperidone,
amisulpride,
aripiprazole,
paliperidone and
ziprasidone were associated with comparable rates of
laxative use. In contrast,
sulpiride was least associated with
laxative use among all SGAs. Regular
laxative use at discharge was found to be significantly associated with psychiatric
rehospitalization. Also, rate of
laxative use at discharge increased significantly during the study period.
Laxative use is common in
schizophrenia patients treated with SGAs. For clinically significant
constipation, switching to an SGA with a lower risk for
constipation, and decreasing the doses of SGAs and
anticholinergics should be considered.