# Thromboembolic events with olanzapine: a systematic review integrating meta-analysis and FAERS database

## TL;DR

This study finds that the antipsychotic drug olanzapine is linked to a higher risk of dangerous blood clots in the lungs and veins.

## Contribution

The study combines meta-analysis and FAERS database mining to show olanzapine increases thromboembolic risk.

## Key findings

- Olanzapine use significantly increases the risk of venous thromboembolism and pulmonary embolism.
- Serious adverse events like pulmonary embolism were identified in FAERS data not fully reflected on drug labels.

## Abstract

Olanzapine is an atypical antipsychotic used to treat schizophrenia and manic episodes. Its potential thromboembolic risk has been reported, but the evidence remains controversial. This study aimed to comprehensively evaluate the association between olanzapine and pulmonary embolism (PE) and venous thromboembolism (VTE).

This study combined meta-analysis and signal mining from the FDA Adverse Event Reporting System (FAERS) database to assess the association between olanzapine and pulmonary embolism (PE) and venous thromboembolism (VTE).

From 55,905 olanzapine-related adverse event reports in the Faers database, 1,233 significant signals were identified, including serious adverse events not fully documented on the drug label, such as pulmonary embolism and venous embolism. A meta-analysis of eight studies showed that olanzapine use significantly increased the risk of VTE and pulmonary embolism (OR = 2.07, 95% CI: 1.37–3.14, P = 0.0006).

These findings suggest that olanzapine is associated with an increased risk of thromboembolic events; therefore, enhanced clinical surveillance and further investigation into its safety are necessary.

https://www.crd.york.ac.uk/prospero/, identifier CRD420251003254.