Assessing the Rate of Antipsychotic Use in Ambulatory Care Patients With a Venous Thromboembolism

Fatal pulmonary embolism in patients on antipsychotics: case series, systematic review and meta-analysis

Since the 1950 s, several studies have reported that patients using first generation and/or second-generation antipsychotics had increased risk of venous thromboembolism events. These events include deep vein thrombosis and/or pulmonary embolism (PE). However, data about fatal PE in patients on antipsychotics (APs) remain scarce. Thus, the current study aimed to investigate sociodemographic, clinical and pharmacological characteristics related to psychiatric patients on APs and who died from a fatal PE. We reported a case-series, then conducted a literature review of relevant studies and performed a meta-analysis of studies with usable data. The main outcome of the study suggested a significantly high risk of fatal PE in patients using APs compared to nonusers (Odds Ratio=6.68, with 95% confidence interval 1.43-31.11). Clozapine was the most incriminated drug. Low potency first generation APs were the second most exhibited medication. Studies about the topic remain scarce with a high heterogeneity and a high probability of bias. Further studies are needed to ascertain this risk and to establish target preventive measures in this particularly vulnerable population.

Current antipsychotic agent use and risk of venous thromboembolism and pulmonary embolism: a systematic review and meta-analysis of observational studies

BACKGROUND

Antipsychotic agents (APS) are widely used drugs to treat psychotic symptoms and can effectively reduce both positive and negative symptoms of schizophrenia. For decades, some studies suggested that there is a relationship between using APS and the risk of venous thromboembolism (VTE) and pulmonary embolism (PE). However, results remain inconclusive.

METHOD

This review has been registered in International Prospective Register of Systematic Reviews (PROSPERO, ID: CDR42020155620). Relevant studies were identified among observational studies published up to 1 October 2019 in the databases MEDLINE, EMBASE, and Cochrane Library. Random or fixed-effects models were used to calculate the pooled odds ratio (OR).

RESULTS

In total, 28 observational studies were included. The results showed that compared with non-users, current APS users have significantly increased risks of VTE [OR 1.55 95% confidence interval (CI) 1.36, 1.76] and PE (OR 3.68, 95% CI 1.23, 11.05). Subgroup analyses suggested that new users were associated with a higher risk of VTE (OR 2.06, 95% CI 1.81, 2.35). For individual drugs, increased risk of VTE and PE was observed in taking haloperidol, risperidone, olanzapine, prochlorperazine but not in chlorpromazine, quetiapine or aripiprazole. However, careful interpretation is needed because of high heterogeneity among studies and scarce data.

CONCLUSION

The present comprehensive meta-analysis further indicates a significantly increased risk of VTE and PE in current APS users compared with non-users. Subgroup analyses suggest that new users are more likely to develop VTE. However, due to significant heterogeneity among studies, conclusions should be considered with caution.