Antiemetics in cancer chemotherapy: historical perspective and current state of the art.

Chemotherapy-related nausea and vomiting can today be controlled with available antiemetics in a high percentage of patients but emesis remains a problem for some patients, with certain drugs and with repeated cycles of chemotherapy. The fundamental steps of clinical research in antiemetics towards the improvement of the control of nausea and vomiting with new drugs or combinations are presented. Special emphasis is given to cisplatin-induced nausea and vomiting because of the frequency and relevance of this phenomenon. The use of high-dose metoclopramide, its combination with steroids, and later the addition of lorazepam or diphenhydramine represented the evolving standard of the 1980s, with the level of complete protection from vomiting improving from 30%-40% to 60%-70% with the three-drug combination. The introduction of new agents such as the 5-hydroxytryptamine 3 (5-HT3) receptor antagonists has recently offered new possibilities because of their activity and lack of toxicity. In particular, the combination of ondansetron plus dexamethasone is today the most efficacious and least toxic antiemetic treatment for prevention of emesis in patients treated with a single high dose or low repeated doses of cisplatin. A comparison of different 5-HT3 antagonists, always in combination with steroids, is now considered necessary. For patients treated with moderately emetogenic chemotherapy the use of steroids can still be considered the standard treatment. In this setting, the role of 5-HT3 receptor antagonists, alone or in combination with steroids, has to be better defined through large, well-planned clinical trials, which should have a cost-effectiveness analysis as one of their goals.