Risks and benefits of drugs used in the management of postoperative nausea and vomiting.

Postoperative nausea and vomiting (PONV) is an age-old problem; more so since the blooming of ambulatory or day surgery centres within the last 2 decades. The aetiology of PONV is multifactorial. The incidence of PONV is usually higher in women and children than in men. PONV not only causes patient discomfort, anxiety in mild cases, and serious complications in severe cases, it also decreases cost efficiency. The benefits and risks of old and new antiemetic drugs used worldwide to treat PONV are discussed in this article, including the newly developed serotonin 5-hydroxytryptamine 3 (5HT3) antagonists. All the medications currently used to treat PONV have both advantages and disadvantages. If used indiscriminately to treat patients who have no problems with PONV, the risks of adverse effects often outweigh the benefits. The patient's history and the nature of the surgery are good indicators for defining those at risk from PONV; for patients at risk preventive treatment is essential. However, it is almost impossible to pick one agent or one combination as the therapy of choice using the present available data. A patient history of a favourable response to a previously used antiemetic would make that drug the agent of choice. So far, the newcomers, the 5HT3 antagonists, have fewer reported adverse effects.