Certain antipsychotics tied to increased pneumonia risk

Specific antipsychotic drugs such as high-dose quetiapine, high- and medium-dose clozapine, and high-dose olanzapine appear to be associated with a heightened risk of pneumonia among patients with schizophrenia, as shown in a study.

Researchers used data from the Finnish registers and looked at 61,889 patients with schizophrenia (mean age 46.2 years, 50.3 percent men), including those with schizoaffective disorder. Use of specific antipsychotic monotherapies was examined by dosage (low: <0.6 of the World Health Organization defined daily dose [DDD] per day; medium: 0.6 to <1.1 DDDs per day; high: ≥1.1 DDDs per day), polypharmacy, and anticholinergic burden (low, medium, high).

Over 22 years of follow-up, 8,917 patients (14.4 percent) were hospitalized at least once for pneumonia. Of these patients, 1,137 (12.8 percent) died within 30 days of admission.

Multivariable Cox proportional hazards regression models showed that compared with no antipsychotic use, any antipsychotic use overall showed no association with pneumonia (adjusted hazard ratio [aHR], 1.12, 95 percent confidence interval [CI], 0.99–1.26). However, monotherapy was associated with a risk increase (aHR, 1.15, 95 percent CI, 1.02–1.30; p=0.03) in a dose-dependent fashion, whereas polytherapy was not.

When categorized by anticholinergic burden, only the use of antipsychotics with a high anticholinergic burden showed a significant association with pneumonia (aHR, 1.26, 95 percent CI, 1.10–1.45; p<0.001).

When analysing specific drugs, increased pneumonia risk was observed with high-dose quetiapine (aHR, 1.78, 95 percent CI, 1.22–2.60; p=0.003), high- and medium-dose clozapine (high dose: aHR, 1.44, 95 percent CI, 1.22–1.71; p<0.001; low dose: aHR, 1.43, 95 percent CI, 1.18–1.74; p<0.001), and high-dose olanzapine (aHR, 1.29, 95 percent CI, 1.05–1.58; p=0.02).

The findings underscore the importance of implementing pneumonia prevention strategies aimed at patients with schizophrenia requiring high-risk antipsychotics.