Psychotropic drugs and fatal pulmonary embolism

To examine the association between the use of psychotropic drugs and fatal pulmonary embolism.

We conducted a national case-control study of fatal pulmonary embolism. Cases were 75 New Zealand men and women aged 15-59 years who died between 1 January 1990 and 31 December 1998, where the underlying cause of death was certified as codes 415.1, 451 or 453 of the International Classification of Diseases (9th Revision). Four controls, matched for sex and age, were selected from the general practice to which each case had belonged. Information was abstracted from the records of general practitioners, family planning clinics and psychiatric services. Odds ratios and 95% confidence intervals (95% CI) were estimated using conditional logistic regression. The key analyses were restricted to cases (n = 62) and controls (n = 243) without major risk factors for venous thromboembolism.

Compared to non-use, the adjusted odds ratio for current use of antipsychotic drugs was 13.3 (95% CI: 2.3-76.3). Low potency antipsychotics appeared to carry the highest risk (odds ratio: 20.8 [95% CI: 1.7-259.0]). The main drug involved was thioridazine. The odds ratio for current use of antidepressants was also increased, at 4.9 (95% CI: 1.1-22.5).

Our results for conventional antipsychotics are consistent with previous studies of non-fatal venous thromboembolism. The finding for antidepressants needs to be replicated in other studies.