The Effect of Clozapine on Self-reported Duration of Sleep and Its Interaction With 23 Other Medications: A 5-Year Naturalistic Study.

Background: Sedation is a common and incapacitating clozapine adverse effect, but the factors associated with sedation and its pharmacological management remain poorly studied.

Methods: We conducted a retrospective cohort study based on deidentified electronic clinical records of clozapine-treated patients from the secondary mental health care provider for Cambridgeshire and Peterborough, United Kingdom. We first evaluated cross-sectionally the influence of clozapine dose, clozapine, and norclozapine plasma levels on self-reported hours slept, as a proxy for sedation, using bivariate correlation and then the longitudinal effect of changes in clozapine dose and other 23 medications using linear mixed effect models.