Benefits and Risks of Newer Treatments for Chemotherapy-Induced and Postoperative Nausea and Vomiting

Nausea and vomiting are common adverse effects of chemotherapy, radiation therapy, anaesthesia and surgery. The incidence of chemotherapy-induced nausea and vomiting (CINV) is estimated to vary from 30 to 90%, depending on the type of chemotherapeutic agent used. Radiation-induced emesis varies with anatomical site radiated but is estimated to have an overall incidence of approximately 40%. The incidence of postoperative nausea and vomiting (PONV) depends on the type of anaesthesia and surgery, but overall is estimated to be 20–30%. Evidence-based medicine and meta-analysis have been used to direct medical therapy to help determine equivalence, optimal dose, timing, safety and efficacy of antiemetic medications. Concepts such as the number needed to treat and number needed to harm are helpful to guide the clinician regarding the benefits and risks of a particular treatment.