COVID-19 disease outcomes in patients receiving clozapine versus other antipsychotics: A national study in Qatar

Dalia Albahari¹Oraib Abdallah¹Shatha Alqam¹Mohammed Faisal Hamad Mohammed¹Mohamed Ali Siddig Ahmed¹Ovais Wadoo^1,2*

• ¹Hamad Medical Corporation, Doha, Qatar
• ²College of Medicine, Qatar University, Doha, Qatar

Clozapine has immunomodulatory effects that raised concerns about its potential to exacerbate severe COVID-19. This study examines whether clozapine use is associated with worse COVID-19 outcomes in patients with schizophrenia.This retrospective cohort study compared COVID-19 outcomes in SARS-CoV-2-infected patients on clozapine versus those on other antipsychotics. Primary outcomes included severe disease, hospitalization, ICU admission, and mortality. Descriptive statistics summarized the data, with categorical variables analyzed via Chi-square tests and exact Fisher test. The continuous variables were analyzed via Student's t-test. Logistic and linear regression analyses estimated odds ratios while adjusting for confounders.Thirty-three patients on clozapine (29.7%) tested positive for SARS-CoV-2 and were compared to 132 SARS-CoV-2-positive patients on non-clozapine antipsychotics. Severe infection rates did not significantly differ (clozapine: 3%, non-clozapine: 7.69%, p = 0.340), nor did hospitalization rates (clozapine: 15.1%, non-clozapine: 16.9%, p = 0.807). All clozapine patients survived, while one death (0.7%) occurred in the non-clozapine group. The mean hospital stay was similar (clozapine: 8.8 days, SD = 2.2; non-clozapine: 11.5 days, SD = 1.9; p = 0.515).