Prochlorperazine

Cardiovascular

There was an association between the use of antipsychotic drugs and the risk of venous thromboembolism in a large nested case-control study using the UK QResearch primary-care database [ ]. Cases (n = 25 532) with a first ever record of venous thromboembolism were matched with up to four controls (n = 89 491) by age, calendar time, sex, and practice. Those who had used antipsychotic drugs in the previous 24 months had a greater risk of venous thromboembolism than non-users, and the risk was greater with atypical than conventional drugs. The risk was also greater with low-potency rather than high-potency drugs; quetiapine presented the highest risk (OR = 2.81; 95% CI = 1.75, 4.50). The risk increased with age; the estimated number of extra cases of venous thromboembolism per 10 000 patients treated over 1 year was 4 (3–5) in patients of all ages and 10 (7–13) for patients aged 65 and over. Prochlorperazine accounted for almost 80% of all prescriptions.

Prochlorperazine inhibits HERG channels in vitro [ ] and can cause QT interval prolongation and cardiac dysrhythmias [ ].