Preemptive antiemesis in patients undergoing modified radical mastectomy: oral granisetron versus oral ondansetron in a double-blind, randomized, controlled study.

Study Objective: To assess the efficacy of oral granisetron versus oral ondansetron for preemptive antiemesis in women undergoing modified radical mastectomy.

Design: Randomized, double-blind, controlled study.

Setting: Metropolitan hospital.

Patients: Ninety ASA physical status I and II hospitalized female patients, aged 18 to 65 y, scheduled for modified radical mastectomies.

Interventions: Patients were assigned to receive orally placebo, granisetron 2 mg, or ondansetron 4 mg (n = 30 in each group) 1 h before induction of anesthesia. A standard general anesthetic technique and postoperative analgesia were used.

Measurements: Postoperative nausea and vomiting and safety assessments were performed continuously 0 to 2, 2 to 6, 6 to 12, and 12 to 24 h after anesthesia.

Main Results: A complete response during 0 to 2 h after anesthesia was found in 43%, 63%, and 90% of patients who had received placebo, granisetron, or ondansetron, respectively; corresponding percentages of patients requiring rescue antiemetics were 40%, 17%, and 7%. Frequency of nausea and vomiting was low (less than 23%) after 2 h in the three groups. Observations of postoperative nausea and vomiting score and need for antiemetics at other time intervals (2 to 6, 6 to 12, and 12 to 24 h) were not significantly different among the three groups.

Conclusion: Oral ondansetron 4 mg provided better preemptive antiemesis than oral granisetron 2 mg in the 2 h after modified radical mastectomy during general anesthesia.