Ondasetron versus granisetron in the prevention of chemotherapy-induced nausea and vomiting. Results of a prospective randomized trial

BACKGROUND: A single-institution, prospective, randomized open trial was performed to compare ondansetron and granisetron in the prevention of chemotherapy-related nausea and vomiting. The effect of antemetic drugs was analyzed indipendently for patients treated with highly emetogenic chemotherapy (Study 1), and those treated with moderately emetogenic regimens (Study 2). METHODS: In Study 1, 182 patients treated with chemotherapeutic regimens containing high dose cisplatin (more than 70 mg/m2) were randomized to receive 24 mg of ondasentron intravenously (i.v.) or 3 mg of granisetron i.v. for the control of acute emesis. Patients treated with fractionated chemotherapy and those followed-up for delayed emesis also received 8 mg of ondansetron orally twice a day or 3 mg of granisetron i.v. on the days after Day 1. In Study 2, 164 patients were randomized to receive either 16 mg of ondansetron i.v. or 3 mg of granisetron i.v. to prevent emesis in the first 24 hours. RESULTS: In the ondansetron group in Study 1, a complete response (CR) (i.e., no vomiting, nausea possible) from acute emesis was achieved in 52% of cases, a major response (MR) in 29%, and a minor response (MiR) in 14%. In the granisetron group in Study 1, a CR was seen in 49% of patients, an MR in 24%, and an MiR in 12%. Failure was recorded in 5% and 15% of cases in the ondansetron and granisetron groups, respectively. No statistically significant difference in any response category was seen between the two groups. In the ondansetron group, a complete protection from delayed emesis was recorded in 39% of cases, an MR in 32%, an MiR in 21%, and failure in 16%. In the granisetron arm, 36% of the patients had a CR, 22% had an MR, 14% had an MiR, and 14% experienced treatment failure. Again, these differences did not reach statistical significance. In Study 2, no statistical significant difference was observed between the ondansetron arm and the granisetron arm, both for acute and delayed emesis. Both ondansetron and granisetron were tolerated very well by most patients, with no severe side effects. In the group of patients treated with ondansetron, however, the incidence of headache (9%) was higher than in the group treated with granisetron (4%). CONCLUSIONS: These data suggest that although both ondansetron and granisetron are very effective drugs for the control of acute emesis, their efficacy against delayed emesis is still not entirely satisfactory.