5-HT3 RECEPTOR ANTAGONISTS - DIFFERENCES AND SIMILARITIES

Differences among 5-HT3 receptor antagonists have been reported in pha rmacological studies with regard to selectivity of receptor binding, p otency, duration of action and dose-response curves. However, whether these pharmacological differences can affect clinical efficacy and saf ety remains to be determined. A careful analysis of the literature rev ealed 22 comparative studies among the 5-HT, receptor antagonists avai lable for review. Unfortunately, several of these trials have some imp ortant shortcomings especially in the study design, the size of popula tion studied and the type of anti-emetic treatment selected, making th eir conclusions often difficult to interpret. However, among these stu dies, seven large, double-blind clinical trials have clearly shown tha t the antiemetic activity and tolerability of ondansetron, granisetron , tropisetron and dolasetron is almost identical at least in the preve ntion of cisplatin-induced emesis. Therefore, from the efficacy and sa fety point of view, there is no reason to prefer one with respect to t he other compound. From the economic perspective, instead, differences may exist and they are strictly related to the dose and schedule of a dministration chosen for each compound. The information available on t he use of 5-HT3 receptor antagonists in the prevention of emesis induc ed by moderately emetogenic chemotherapy is at best scant. Contrasting results have been reported and only one well-conducted study has been published in full. Therefore, the possible differences among the vari ous compounds are difficult to evaluate. More studies should be carrie d out in this group of patients. (C) 1997 Elsevier Science Ltd.