Chemotherapy-induced nausea and vomiting: which antiemetic for which therapy?

Chemotherapy-induced nausea and vomiting (CINV) remains an important and common toxicity of cancer treatment. Recent guideline revisions have classified chemotherapeutic agents into four categories of emesis risk without the use of preventive agents: high (> 90%), moderate (30%--90%), low (10%-30%), and minimal (< 10%). Currently available antiemetic agents, including corticosteroids, 5-hydroxytryptamine (HT)3 receptor antagonists, and neurokinin (NK)-1 antagonists are used alone or in combination depending on the level of emetogenic potential as prophylaxis against the development of CINVduring the acute period (up to 24 hours after chemotherapy) and the delayed period (up to 5 days after treatment). Newer agents, including the second-generation 5-HT3 receptor antagonist palonosetron (Aloxi) and the NK-1 antagonist aprepitant (Emend), offer additional clinical benefit in highly and moderately emetogenic therapy. However, delayed nausea and vomiting continue to occur frequently in many patients and have an impact on quality of life. Other classes of agents including the benzodiazepines and cannabinoids offer the potential for additional protective benefit. Continued research with new drugs and combinations is necessary to meet this significant unmet need of cancer patients.