It’s Too Soon to Throw Away Oral Ondansetron for Pediatric Gastroenteritis

OBJECTIVE: To evaluate the antiemetic efficacy of a modified regimen of oral ondansetron and dexamethasone in patients with lupus nephritis undergoing treatment with cyclophosphamide whose conventional antiemetic regimen had failed. DESIGN: A before-after prospective observational pilot project. SETTING: A federal research hospital. PATIENTS: Fourteen outpatients with lupus nephritis receiving intravenous cyclophosphamide 0.75–1.0 g/m2 had previously experienced chemotherapy-induced emetic events (vomiting or retching) while receiving a standard combination intravenous antiemetic regimen. The regimen consisted of four doses of thiethylperazine 10 mg and diphenhydramine 25 mg every 6 hours, and two doses of lorazepam 0.5 mg every 6 hours starting 1 hour prior to cyclophosphamide. A subset of 8 patients previously completed a blinded study in which they received the intravenous formulation of ondansetron (4 doses of 4–16 mg q4h) administered orally beginning 30 minutes prior to the cyclophosphamide infusion. MAIN OUTCOME MEASURES: The number of emetic events and cost of drug administration were assessed for the modified ondansetron intervention and compared with those of the standard antiemetic regimen. The incidence of emetic events and visual analog nausea scores for the subset of eight patients were also evaluated. INTERVENTIONS: To account for the delayed onset of emesis associated with cyclophosphamide, patients received both ondansetron 8 mg orally every 4 hours (3 doses) and dexamethasone 10 mg orally (1 dose) beginning 4 hours after the cyclophosphamide infusion. This is different from the manufacturer's recommended dose schedule, in which ondansetron is administered prior to chemotherapy. RESULTS: NO emetic events were observed following the administration of oral ondansetron/dexamethasone. The 95% confidence interval for the true rate of emesis was 0% to 19.3%. There was a significant difference in efficacy between ondansetron/ dexamethasone and the triple antiemetic regimen (p < 0.0002). None of the patients experienced adverse effects while receiving the ondansetron/dexamethasone regimen. Cost comparisons (including admixture and nursing administration times) for standard combination therapy and oral ondansetron/dexamethasone were $109.09 and $70.24, respectively. No difference in emetic events or nausea ratings was observed between oral ondansetron/ dexamethasone tablets and oral administration of ondansetron using the intravenous formulation. CONCLUSIONS: This study suggests that a modified oral ondansetron/ dexamethasone regimen is safe and efficacious, and costs less than alternative regimens to prevent cyclophosphamide-induced emesis in patients with lupus nephritis.

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Effect of schedule and maintenance on the antiemetic efficacy of ondansetron combined with dexamethasone in acute and delayed nausea and emesis in patients receiving moderately emetogenic chemotherapy: a phase III trial by the National Cancer Institute of Canada Clinical Trials Group.

Journal of Clinical Oncology ◽

10.1200/jco.1994.12.5.1050 ◽

1994 ◽

Vol 12 (5) ◽

pp. 1050-1057 ◽

Cited By ~ 80

Author(s):

L Kaizer ◽

D Warr ◽

P Hoskins ◽

J Latreille ◽

W Lofters ◽

...

Keyword(s):

Emetogenic Chemotherapy ◽

Phase Iii ◽

Double Blind Study ◽

Moderately Emetogenic Chemotherapy ◽

Severe Nausea ◽

Double Blind ◽

Antiemetic Efficacy ◽

Delayed Nausea ◽

Nausea And Emesis ◽

Oral Ondansetron

PURPOSE This study examines whether the schedule of ondansetron significantly influences its antiemetic efficacy in the first 24 hours after chemotherapy, whether the administration of oral ondansetron after 24 hours is effective in preventing delayed emesis, and whether the efficacy of ondansetron is preserved over multiple courses of moderately emetogenic chemotherapy. PATIENTS AND METHODS A multicenter double-blind study randomized 302 cancer patients to one of three treatment arms. Arm A received dexamethasone 10 mg intravenously (i.v.) plus ondansetron (Zofran; Glaxo Canada Inc, Toronto, Canada) 8 mg i.v. prechemotherapy plus ondansetron 8 mg orally every 12 hours postchemotherapy for nine doses. Arm B received dexamethasone 10 mg i.v. plus ondansetron 16 mg i.v. prechemotherapy plus placebo orally postchemotherapy in the same schedule as arm A. Arm C received dexamethasone 10 mg i.v. plus ondansetron 8 mg prechemotherapy plus ondansetron 8 mg orally postchemotherapy for one dose followed by placebo orally every 12 hours for eight more doses. Response was assessed by the number of reported episodes of vomiting and by severity of nausea measured on a visual analog scale (VAS). RESULTS The two schedules of ondansetron used in the first 24 hours were no different in their antiemetic efficacy, with similar rates for complete responses (76.7% v 72.0%, P = .472), complete plus major responses (90.2% v 82.0%, P = .135), and severity of nausea (P = .348). Oral ondansetron after 24 hours was more effective than placebo in preventing delayed nausea and emesis, with superior rates of complete responses (59.6% v 42.1%, P = .012 by one-sided test), complete plus major responses (80.9% v 66.3%, P = .018 by one-sided test), and less severe nausea (9.2 mm v 18.6 mm on a 100-mm VAS, P = .002). The efficacy of ondansetron was maintained over subsequent courses of chemotherapy. CONCLUSION The schedule of ondansetron in the first 24 hours does not influence its efficacy. The use of oral maintenance ondansetron is effective in preventing delayed maintenance ondansetron is effective in preventing delayed nausea and emesis after moderately emetogenic chemotherapy.

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