Postoperative nausea and vomiting: a comparison of anti-emetic drugs used alone or in combination.

Drugs with anti-emetic properties can exert their actions at more than one receptor site, histamine H1, muscarinic cholinergic or dopaminergic D2 receptors. This study was designed to test the hypothesis that a combination of drugs acting at different receptor sites in lower than standard doses would be at least as effective as a standard therapeutic dose of a single anti-emetic agent. A combination of droperidol, hyoscine and metoclopramide in subtherapeutic doses has been shown to be at least as effective as droperidol (1.25 mg) alone. In both groups there was a low incidence of emetic sequelae in the first 3 hours postoperatively.