Low-dose droperidol
===================

* Greg Allen

Eric Wooltorton's recent drug alert1 on droperidol adds little to the scant information initially released by the US Food and Drug Administration (FDA). Droperidol has a long history of safe use, is inexpensive and effectively treats postoperative nausea and vomiting. Millions of patients have received droperidol, suggesting that the rate of cardiac complications is extremely low. The new recommendations for giving droperidol (preoperative electrocardiogram, 2–3 hours of postoperative cardiac monitoring) will effectively kill its use. 

Studies of droperidol's effect on cardiac conduction have used doses (0.25 mg/kg) far above those used to control postoperative nausea and vomiting (0.625 mg).2 The FDA has admitted that it has little data on low-dose droperidol, yet it has published the “black box” warning. The FDA has since announced that it is conducting a “definitive pharmacokinetic/pharmacodynamic study” on low-dose droperidol, as well as a comparison between droperidol and other antiemetics and their respective adverse effects. 

Health Canada released a drug safety letter on Feb. 123 but did not address it to anesthesiologists. It repeated the December FDA warning without details of the QT prolongation cases that prompted the letter. Perhaps after the cisapride fiasco, Health Canada wished to forestall further criticism rather than actually enlighten physicians. This is not in the public's best interest, especially if they are nauseated postoperative patients. 

**Greg Allen** Anesthesiologist Providence St. Peter Hospital Olympia, Wash. 

## References

1.  1. Wooltorton E. Droperidol: cardiovascular toxicity and deaths. CMAJ 2002;166(7):932. 
    
    [FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiRlVMTCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czo5OiIxNjYvNy85MzIiO3M6NDoiYXRvbSI7czoyMjoiL2NtYWovMTY3LzUvNDUyLjIuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9) 

2.  2. McCormick CG. FDA Alert: Current FDA report on droperidol status and basis for “Black Box” warning. ASA Newsletter 2002;66(4):19-20. 
    
    

3.  3. Health Canada. *Cardiovascular toxicity with injectable droperidol*. Ottawa: Health Canada; 2002 Feb 12. Available: [www.hc-sc.gc.ca/hbp-dgps/therapeut/zfiles/english/advisory/tpd/droperidol\_e.html](http://www.hc-sc.gc.ca/hbp-dgps/therapeut/zfiles/english/advisory/tpd/droperidol_e.html) (accessed 2002 July 8).