A RCT of Ondansetron and Promethazine in the Treatment of Nausea and Vomiting in the Emergency Department

Nausea and vomiting are common complaints in the emergency department (ED). There are many pharmacologic agents used for the treatment of these complaints. None are new nor experimental. Very little research has been done in the ED setting to determine which of these agents is most effective with the least adverse effects. Our own previous research found that droperidol but not prochlorperazine and metoclopramide is more effective than placebo. Because of the recent FDA black box warning added to droperidol, the use of this agent has suddenly ceased in many EDs. Promethazine remains a very commonly used antiemetic in many EDs but one recent study found it less effective than prochlorperazine which was in turn found no more effective than placebo in our own study. As a result many physicians have turned to ondansetron, a newer and more expensive agent. Experience among anesthesiologists and oncologists has shown ondansetron to be highly effective with a minimum of adverse effects. These patient populations, however, are very different from those found in the ED. It is our hypothesis that promethazine and ondansetron are equally effective for the ED treatment of unselected patients with nausea and vomiting with similar rates of adverse effects.

Inclusion criteria

• Age 18 or older
• Chief complaint of nausea or vomiting

Exclusion criteria

• Age less than 18
• unable to provide informed consent
• rate nausea at < 40 mm on 100 mm VAS
• received antiemetic within 24 hours
• pregnant or possibly pregnant
• reported allergy to either study medication
• received more than 1 liter of intravenous fluids
• their primary ED physician declined to have patient participate