Antiemetic use for nausea and vomiting in adult emergency department patients: randomized controlled trial comparing ondansetron, metoclopramide, and placebo.
 Egerton-Warburton D, Meek R, Mee MJ, Braitberg G.
 Ann Emerg Med. 2014 Nov;64(5):526-532.
Reductions in nausea severity for this adult ED nausea and vomiting population were similar for 4 mg intravenous ondansetron, 20 mg intravenous metoclopramide, and placebo. It is interesting that two commonly administered medicines, one of them an expensive one, are little better than a saline infusion.