Nausea and Vomiting

Abstract

The introduction of two new classes of antiemetics, the 5 hydroxytryptamine 3 receptor antagonists (5HT3 RAs) and the neurokinin1 receptor antagonists (NK1 RAs) have revolutionised the treatment of post-chemotherapy acute and delayed nausea and vomiting, and this in turn has decreased the incidence of anticipatory emesis. Triple antiemetic therapy combining a 5HT3 RA and NK1 RA with dexamethasone is recommended by MASCC for the prevention of nausea and vomiting, associated with chemotherapy of high emetic potential and the anthracycline/cyclophosphamide (AC) regimen. Nausea is not as well controlled as vomiting but is a symptom that has multiple associated symptoms to treat. There are few differences between 5HT3 RAs, except palonosetron with a longer half-life and better control of delayed emesis with non-AC chemotherapy of moderate emetic potential, where it is the recommended 5HT3 RA. Single agents are recommended for the prevention of emesis in patients receiving chemotherapy of low emetic potential and who have a prior history of emesis while no antiemetic prevention is recommended prior to chemotherapy of minimal emetic potential. Older antiemetics such as dopamine antagonists and adjuvant drugs such as the benzodiazepines can be used for emesis that is refractory to the above antiemetic regimens. More research is needed into the optimal antiemetic regimens for children receiving chemotherapy, patients receiving high dose chemotherapy and those being treated with radiotherapy.