What is the ideal combination antiemetic regimen?

Postoperative nausea and vomiting (PONV) and post-discharge nausea and vomiting (PDNV) are frequent unpleasant complaints that patients and clinicians report after surgery. PONV and PDNV have been associated with postoperative complications and hospital discharge delays. Despite the extensive evidence describing the use of several regimens in different surgical populations, the ideal regimen has not been established. Several antiemetic drugs have been evaluated in more than 1000 clinical controlled trials for management of this complex emetogenic pathway, including the 5-hydroxytryptamine (5-HT3) receptor antagonists, dopamine receptor antagonists, neurokinin-type receptor antagonists, antihistaminics, anticholinergics, and corticosteroids, with the 5-HT3 receptor antagonists being the most commonly used for PONV prophylaxis. Because of the complex emetogenic pathway and multifactorial etiology of PONV, a multimodal approach using two or more drugs that act at different neuro-receptor sites is suggested in patients with one or more risk factors to successfully address PONV and reduce its incidence. Nevertheless, the most studied regimens in randomized clinical trials (RCTs) are the combination of serotonin 5-HT3 receptor antagonists with dexamethasone or dopamine receptor antagonists (droperidol). Therefore, the safest and more effective combination regimen appears to be the use of serotonin 5-HT3 receptor antagonist antiemetic drugs with dexamethasone.