Clozapine use at a specialised psychiatric hospital in Johannesburg.

Background: Clozapine is the gold standard medication for treatment-resistant psychosis, with robust evidence supporting its efficacy in multiple symptom domains. However, clozapine's side effect profile contributes to its underutilisation and discontinuation.

Aim: This study aimed to explore the magnitude of clozapine use and describe factors that impact on its effective use among in-patients.

Setting: Tara Hospital, a specialised psychiatric hospital in Johannesburg.

Methods: This was a retrospective, cross-sectional file review of clozapine-treated patients admitted over the 2-year study period. Data variables included: demographics, clinical information, discharge prescription, clozapine-related side effects and details of clozapine discontinuation, where applicable.

Results: A cohort of 33.2% of patients from Tara's biological wards received a trial of clozapine. Participants experienced anti-cholinergic clozapine-related side effects that included weight gain (79.5%), tachycardia (35.2%) and constipation (35.2%). Clozapine was discontinued in 13.7% of participants, and no life-threatening side effects or deaths occurred. Significantly more use of flupenthixol decanoate (64.3% vs. 30.7%; p = 0.0322) and anticholinergics (35.7% vs. 11.4%; p = 0.0474) occurred in the clozapine-discontinued group. Polypharmacy rates were high for psychiatric and non-psychiatric medications.

Conclusion: One-third of patients received clozapine trials, most of whom continued at discharge. Although side effects occurred frequently, life-threatening side effects did not. Clozapine monitoring protocols, side effect rating scales, pre-emptive management of side effects, lifestyle interventions and clinician education may improve outcomes of clozapine use. The use of plasma clozapine levels may be beneficial.

Contribution: This study expands our limited knowledge regarding current clozapine prescribing trends in South Africa.