The effect of ondansetron, a 5-HT3 antagonist, in preventing postoperative nausea and vomiting was investigated in a randomized, double-blind, placebo-controlled study of 84 patients undergoing gynecologic operation and receiving the same general anesthetic. The patients received premedication with either 16 mg oral ondansetron, or a matching placebo. The same medication was given postoperatively 8 h after the first dose. During the first hour after recovery from anesthesia, the frequencies of nausea and vomiting were 52% and 40%, respectively, in patients given placebos. In the ondansetron group nausea and vomiting developed in 17% and 12%, respectively, values significantly different from those with placebos (P less than 0.005). Similar differences were observed throughout the entire 24-h period after recovery, the incidence of nausea and vomiting being 67% and 60%, respectively, in the placebo group and 29% and 26% in the ondansetron treatment group. Ondansetron appears to be a promising antiemetic for the prevention of postoperative nausea and vomiting.

When given at induction of anesthesia, 50 mg intravenous dolasetron is equivalent to 4 mg ondansetron and superior to 25 mg dolasetron and placebo for the prevention of PONV. All treatments were safely administered and well tolerated.

In a placebo-controlled, double-blind study, we have compared the efficacy of ondansetron 16 mg, 8 mg and 1 mg administered 8-hourly for prevention of postoperative nausea and vomiting. We studied 995 patients undergoing major gynaecological surgery; 982 were included in the analysis. Study medication was administered 1 h before induction of anaesthesia and second and third doses were given 8 and 16 h after the first. The treatment groups were similar for patient characteristics, surgical procedures, anaesthetics administered and opioids given. The frequency of nausea was 75%, 70%, 56% and 55% after placebo and ondansetron 1 mg, 8 mg and 16 mg, respectively; the corresponding frequencies of vomiting were 60%, 55%, 37% and 37%. Ondansetron 8 mg was as effective as 16 mg and both resulted in significant reductions in nausea and vomiting compared with placebo and ondansetron 1 mg (P less than 0.001).

Intravenous dolasetron mesilate ameliorates postoperative nausea and vomitingPurpose: To compare the efficacy, safety, and tolerability of dolasetron mesilate with placebo for the treatment of postoperative nausea and vomiting (PONV), Methods: In a randomized, multicentre, double-blind, placebo-controlled study 337 adult patients undergoing surgery with general anaesthesia received one of four single, doses of dolasetron mesilate iv (I 2.5, 25, 50, or I00 mg) or placebo, Study medication was administered postoperatively when the patient reported nausea lasting 10 rain or when one emetic episode occurred within two hours of the patient's arrival in the recovery room. Efficacy was assessed by the investigators over the 24-hr study period by recording the number and timing of emetic episodes, the severity of nausea, the timing of administration of escape antiemetic medications, and patients' and investigators' satisfaction with antiemetic therapy, Results: The study sample was predominately women, and the surgical procedures were primarily gynaecological, All dolasetron mesilate doses produced higher complete response rates than placebo (P<0.05). Only approximately one-third of dolasetron patients required escape antiemetic medication compared with more than 50% of patients in the placebo group, Both patient and physician satisfaction with dolasetron treatment was high. The most common adverse event was mild or moderate headache for both placebo-treated patients and dolasetron-treated patients, Clinical laboratory results were unremarkable. Conclusion: Single doses of dolasetron mesilate iv, given after the first episode of PONV, were both effective and safe in this adult patient population.Objectif : Comparer I'efficacit6, la s6curit6 et I'acceptabilit6 du m6silate de dolasetron avec celles d'un placebo pour le traitement des naus6es et vomissements postop6ratoires (NVPO). M~thodes : Au cours d'une 6rude multicentrique, en double aveugle, contr616e par placebo, 337 adultes soumis ~ une chirurgie sous anesth~sie g6n~rale ont regu du m6silate de dolasetron ~ une de quatre posologies iv (I 2,5, 25, 50, ou 100 mg) ou un placebo. Le m6dicament 6tait administr6 en postoperatoire Iorsque le patient se plaignait d'une naus6e de dur~e I0 min ou quand au moins en 6pisode 6m~tique survenait au cours des deux heures suivant I'arriv6e du patient en salle de r6veil, Sur une p6riode d'6tude de 24 h, I'efficacit6 etait 6valu6e par les investigateurs par I'enregistrement du nombre et de la chronologie des 6pisodes, la gravit6 de la naus6e, le temps de I'administration de la m6dication anti~m&ique de rattrapage, et la satisfaction du patient ou de I'investigateur envers le traitement. R~sultats : 126chantillon de la population 6tudi6e comprenait surtout des femmes et les interventions 6taient surtout gyn6cotogiques. Toutes les doses de m6silate de dotasetron procuraient une r6ponse complete plus fr6quente que le placebo (P <0,05), Seulement un tiers environ des patients sous dolasetron ont eu besoin d'un m~dicament anti6m6tique de ...