Antipsychotic Drugs may Increase Pneumonia Risk in Schizophrenia Patients, suggests research

A new study conducted by Jurjen Luykx and team found that antipsychotic medications like olanzapine (>=11 mg/d), quetiapine (>=440 mg/d) and clozapine (at doses ≥180 mg/d) were linked to pneumonia in schizophrenic individuals. These critical findings of the study were published in the recent issue of Journal American Medical Association Psychiatry. This comprehensive study encompassed data from over 61,000 individuals to highlight the complexities and potential dangers associated with antipsychotic treatments by unveiling the heightened risks posed by certain drugs and dosage levels.

The study analyzed nationwide Finnish registers from 1972 to 2014 to clarify the extent to which antipsychotic use is associated with an increased risk of pneumonia, explore dose-response relationships and identify specific drugs related to this risk. The research drew data on diagnoses, inpatient care, and specialized outpatient care from the Hospital Discharge Register and outpatient medication dispensing information from the Prescription Register. Follow-up data from 1996 to 2017 were analyzed between November 2022 and December 2023. The use of certain antipsychotic monotherapies were dose-modeled as low, medium, or high doses with antipsychotic polypharmacy and antipsychotics being classified as low, medium or high anticholinergic burden agents. The hospitalization for incident pneumonia was the main outcome. 

The key findings of this study were:

While general use of antipsychotics was not closely associated with pneumonia, the monotherapy was found to increase pneumonia risk when compared to no antipsychotic use. This risk increased in a dose-dependent manner.

Also, using multiple antipsychotics simultaneously did not show a significant increase in the risk of pneumonia. Antipsychotics with a high anticholinergic burden were associated with a higher pneumonia risk.

The antipsychotic drugs and their dosages that significantly increase pneumonia risk were:

• High and medium doses of clozapine (≥180 mg/day) showed a marked increase in pneumonia risk.
  
• High-dose quetiapine (≥440 mg/day) was associated with a significantly increased risk.
• High-dose olanzapine (≥11 mg/day) also showed an elevated risk.

The dose-dependent risk and the specific association of higher anticholinergic burden antipsychotics with pneumonia requires the development of prevention strategies customized for patients who require these high-risk medications. As pneumonia poses a serious health threat, understanding the risks linked to antipsychotic treatments is highly important in improving the patient outcomes, reducing the rate of hospitalizations and mortality among the individuals with schizophrenia.

Reference:

Luykx, J. J., Correll, C. U., Manu, P., Tanskanen, A., Hasan, A., Tiihonen, J., & Taipale, H. (2024). Pneumonia Risk, Antipsychotic Dosing, and Anticholinergic Burden in Schizophrenia. In JAMA Psychiatry. American Medical Association (AMA). https://doi.org/10.1001/jamapsychiatry.2024.1441