[Principles of managing chemotherapy-induced nausea and vomiting].

Chemotherapy-induced nausea and vomiting (emesis) can significantly affect a patient's quality of life, leading to poor compliance with further chemotherapy treatment. For patients treated with emetogenic chemotherapy, it is very important to prevent nausea and vomiting completely. The incidence and severity of nausea and/or vomiting in patients receiving chemotherapy are affected by numerous factors, including: 1) the specific chemotherapeutic agents used; 2) their dosage; 3) the schedule and route of administration; and 4) individual patient variability. Approximately 70 to 80% of all cancer patients receiving chemotherapy experience emesis, whereas 10% to 44% experience anticipatory emesis. The following general principles are recommended. 1) A 5-HT3 receptor antagonist should be administered prior to each day's 1st dose of moderately or highly emetogenic chemotherapy. 2) Dexamethasone should be administered once daily either orally or intravenously for every day of moderately or highly-emetogenic chemotherapy and for 2-3 days after chemotherapy for regimens that are likely to cause significant delayed-emesis. 3) The most effective way to treat anticipatory nausea and/or vomiting is to prevent it by using optimal antiemetic therapy during every cycle of treatment.