Pneumonia Risk: Approximately One-Third Is Due To Clozapine And Two-Thirds Is Due To Treatment-Resistant Schizophrenia

: A recent umbrella review suggested that pneumonia is the most robust of the life-threatening medical events associated with antipsychotic use.1 More importantly, the literature suggests that clozapine appears to be more strongly associated with pneumonia than are other antipsychotics.2 However, clozapine is mainly prescribed in patients with treatment-resistant schizophrenia (TRS); therefore, the risk of pneumonia in clozapine patients is likely to be the result of the combined effects of TRS and clozapine.3 No published study has explored the relative contributions of these two factors.