Body mass index as a predictor of the outcomes of acute clozapine toxicity: a cross-sectional study

Abstract

Acute antipsychotic overdose is frequently reported nowadays. Clozapine is one of the atypical agents that are highly lipophilic, highly protein-bound, has a large volume of distribution, and accumulates in the brain and other tissues. Obesity is an essential factor controlling patients’ treatment and clinical course. The current study aimed to study the prognostic value of body mass index (BMI) in patients with acute clozapine poisoning. All patients were evaluated on admission using the Poison Severity Score (PSS) and Glasgow Coma Score (GCS). The BMI was calculated. Mortality and the need for ICU admission were defined as primary outcomes, whereas secondary outcomes included cardiovascular complications and the need for mechanical ventilation. Thirty-eight patients presented with acute clozapine poisoning. The mean age of included patients was 25.2 ± 6. Patients were categorized regarding BMI into average weight (26.3%), overweight (31.6%), and obese (42.1%). Pearson’s correlation indicated a significant positive correlation between BMI and respiratory rate (r = .364, p = .025). A significant negative correlation existed between BMI and GCS (r = .674, p ≤ .001). ROC curve reveals that BMI is an excellent predictor for the requirement of mechanical ventilation area under the curve (AUC > .9), a fair predictor of ICU admission AUC (.747). BMI had a sensitivity of 100% and specificity of 51.7 for the prediction of ICU admission. In conclusion, obesity increased the severity of toxicity and the incidence of poor clinical outcomes in patients with acute clozapine poisoning.