Ondansetron dose response curve in high-risk pediatric patients.

Author(s): Lawhorn CD, Kymer PJ, Stewart FC, Stoner JM, Shirey R, Volpe P

Affiliation(s): Division of Pediatric Anesthesia, Arkansas Children's Hospital, Little Rock 72202-3591, USA.

Publication date & source: 1997-12, J Clin Anesth., 9(8):637-42.

Publication type: Clinical Trial; Randomized Controlled Trial

STUDY OBJECTIVE: To establish a dose-response relationship for ondansetron, and to evaluate any effects of oral premedication with metoclopramide in pediatric patients undergoing tonsillectomy and adenoidectomy and strabismus surgery. DESIGN: Prospective, randomized, double blind study. SETTING: University affiliated, 280-bed pediatric hospital. PATIENTS: 320 ASA physical status l and II patients between the ages of 2 and 12 years undergoing tonsillectomy and adenoidectomy or strabismus surgery. INTERVENTIONS: Patients were randomized to eight investigational groups. Patients in all eight groups underwent a standard anesthetic. Groups 1, 2, 3, and 4 received intravenous (i.v.) saline or i.v. ondansetron at doses of 0.05 mg/kg, 0.1 mg/kg and 0.15 mg/kg, respectively. Groups 5, 6, 7, and 8 received oral metoclopramide 0.15 mg/kg as well as i.v. saline, and ondansetron 0.05 mg/kg, 0.1 mg/kg, or 0.15 mg/kg. Patients were evaluated for emetic episodes prior to and following discharge. MEASUREMENTS AND MAIN RESULTS: All doses of ondansetron 0.05 mg/kg, 0.1 mg/kg, and 0.15 mg/kg were significantly more effective than placebo in reducing the incidence of emesis prior to, following discharge, and during the first 24 postoperative hours (p < 0.001). There were no significant differences in the occurrence of emesis between the groups receiving ondansetron 0.05 mg/kg, 0.1 mg/kg, and 0.15 mg/kg. The addition of oral metoclopramide 0.15 mg/kg had no effect on the incidence of emesis in the ondansetron or placebo study groups. CONCLUSIONS: Ondansetron is an effective medication for the treatment and prevention of postoperative nausea and vomiting, and a dose of ondansetron 0.05 mg/kg is as effective as 0.1 mg/kg and 0.15 mg/kg. Metoclopramide 0.15 mg/kg has no effect on the incidence of postoperative nausea and vomiting.