Prevalence and Factors Associated with Hypersalivation in Schizophrenia Inpatients Treated with Clozapine: A Retrospective Study.

Hypersalivation, or excessive production and secretion of saliva, can result from associated disorders or adverse drug reactions. It significantly impacts physical health, psychosocial well-being, and quality of life. Clozapine, a gold standard for treatment-resistant schizophrenia, is known to cause hypersalivation in some patients.  This study aimed to determine the prevalence of hypersalivation and identify factors associated with its occurrence in patients with schizophrenia treated with clozapine, either as monotherapy or in combination with other antipsychotics.  This retrospective cohort study was conducted using medical records from inpatients diagnosed with schizophrenia at a tertiary psychiatric hospital. Data were collected from patients treated with clozapine between June 1, 2020, and December 31, 2020. Descriptive statistics were used to describe the prevalence of hypersalivation, and multiple logistic regression was performed to assess the association between hypersalivation and patient characteristics.  A total of 96 patients were included in the study, with a mean age of 44.03 years (SD = 13.27); 72.9% of the patients were male. The overall prevalence of hypersalivation was 14.6%, with 19.51% of patients on clozapine monotherapy and 10.91% of those on clozapine combined with other antipsychotics experiencing hypersalivation. Male sex appeared to reduce the risk for hypersalivation (adjusted OR: 0.36, 95% CI: 0.10-1.33,  = .13), while the use of electroconvulsive therapy (ECT) significantly increased the risk of hypersalivation (adjusted OR: 5.40, 95% CI: 1.22-24.02,  = .03). Other variables, including age, Body Mass Index (BMI), smoking status, alcohol consumption, clozapine dosage, and use of anticholinergics, were not significantly associated with hypersalivation.  The prevalence of hypersalivation in schizophrenia inpatients treated with clozapine was 14.6%. Male sex was associated with a reduced risk of hypersalivation, while ECT use significantly increased the risk. These findings provide valuable insights for clinicians managing patients on clozapine, highlighting the need for careful monitoring, particularly in patients undergoing ECT.