The safety and efficacy of prophylactic ondansetron in patients undergoing modified radical mastectomy

We aimed to evaluate the antiemetic efficacy, safety, and clinical utility of prophylactic ondansetron administered at the end of the surgery for the prevention of postoperative nausea and vomiting (PONV) in a homogenous population of 54 women undergoing modified radical mastectomy (MRM). A standard general anesthetic and perioperative analgesic technique were used. After surgery, patients received either saline placebo or ondansetron 4 mg TV. Episodes of PONV, as well as rescue antiemetic requirements, were recorded for the first 24 h after surgery. The 24-h incidence of PONV (33.3% vs 81.5%; P = 0.0010) was significantly lower in the ondansetron group. The severity of PONV, evaluated by the number of emetic episodes per patient (1.59 +/- 1.90 vs 0.29 +/- 0.66; P = 0.0029), and the rescue antiemetic requirement (59.2% vs 14.8%; P = 0.0019) was significantly lower, in the ondansetron group. Patient satisfaction scores and number needed to prevent PONV (2.07) were significantly better and therapeutically more favorable in the ondansetron group. The incidence of adverse events such as headache, dizziness, and increased liver enzyme levels (number needed to harm = proportional to) was similar in both groups. Administered at the end of the surgery in adult female patients undergoing general anesthesia for MRM, ondansetron 4 mg is effective and safe in preventing PONV. We recommend the clinical practice of routine prophylactic ondansetron to prevent PONV after MRM, as it significantly improves perioperative patient satisfaction and outcome. Implications: We evaluated the antiemetic efficacy, safety, and routine use of prophylactic ondansetron, a "gold standard" antiemetic, in women undergoing radical breast surgery who were at a high risk of postoperative vomiting. We analyzed more meaningful "true" and "therapeutic" outcome measures, and we conclude that prophylactic ondansetron is safe and effective and that its routine use is justified.