Association of Antipsychotic Drugs with the Risk of Recurrent Venous Thromboembolism: A Retrospective Study of Data from a Japanese Inpatient Database.

Background: Approximately a decade has passed since the addition of venous thromboembolism to the list of significant adverse reactions of antipsychotic drugs. However, only a few studies have investigated the relationship between antipsychotic use and venous thromboembolism in the Japanese population.

Purpose: We aimed to evaluate the risk of recurrent venous thromboembolism in users of antipsychotic drugs and update the evidence on venous thromboembolism in the Japanese population.

Methods: A cross-sectional retrospective analysis of data from a large Japanese claims database, managed by Medical Data Vision Co. Ltd., was conducted. Adult patients who experienced venous thromboembolism between October 2014 and September 2018 in acute care hospitals were identified. The risk of recurrent venous thromboembolism was evaluated with logistic regression using demographic variables. The data of patients using antipsychotic drugs within specific therapeutic classes were also evaluated.

Results: We included 8960 patients (mean age, 69 years; 59.2% female). Recurrent venous thromboembolism was observed in 686 patients (7.7%). The risk of recurrent venous thromboembolism was significantly higher in younger patients [< 65 years: reference; 65-74 years: odds ratio (OR) 0.81, 95% confidence interval (CI) 0.66-0.99, p = 0.04; ≥ 75 years: OR 0.77, 95% CI 0.64-0.94, p = 0.01], those with history of surgery (OR 1.39, 95% CI 1.18-1.65, p = 0.01), and anticoagulant users (OR 2.25, 95% CI 1.46-3.48, p = 0.01) and was significantly lower in the presence of comorbidities (OR 0.68, 95% CI 0.58-0.81, p< 0.01) and fractures (OR 0.49, 95% CI 0.26-0.94, p = 0.03). Long-term antipsychotic drug prescriptions (> 14 days) were associated with a higher risk of venous thromboembolism than short-term prescriptions (≤ 14 days) (OR 1.56, 95% CI 1.04-2.34, p = 0.03).

Conclusions: In patients with a history of venous thromboembolism, particular attention should be paid to recurrence in younger patients. If antipsychotic drugs are prescribed for > 14 days to patients with a history of venous thromboembolism, they should be administered carefully, guided by reported findings. Further evaluations using different databases or populations are required to generalize the findings of this study.