Chemotherapy-induced nausea and vomiting: current and new standards in the antiemetic prophylaxis and treatment.

Nausea and vomiting are considered as two of the most distressing side-effects of chemotherapy. Chemotherapy-induced nausea and vomiting have been classified into acute, delayed and anticipatory based on the time of onset. The frequency of nausea and vomiting depends primarily on the emetogenic potential of the chemotherapeutic agents used. With the introduction of the 5-HT3 receptor-antagonists in combination with dexamethasone in the early 1990s approximately 70% of patients receiving highly emetogenic chemotherapy were protected from acute emesis. However, 40% of patients have symptoms in the delayed phase. Another group of antiemetics, the neurokinin-1-receptor-antagonists, have recently been introduced. The addition of neurokinin receptor (NK1 receptor)-antagonists to standard therapy significantly improves emesis protection in the acute and in particular in the delayed phase by approximately 20%. Due to these new developments, revised antiemetic guidelines have been set. Here, the most recent developments in antiemetic therapy, including these guidelines, are reviewed.