Dexamethasone Improves Ondansetron"s Prevention of Radiation-Induced Emesis

NEW YORK AUG 09, 2006 (Reuters Health) - The addition of dexamethasone to ondansetron somewhat improves prophylaxis against radiation-induced emesis (RIE), according to a report in the July 20th Journal of Clinical Oncology.
 
Although the role of ondansetron in the prophylaxis and treatment of RIE is well established, the authors explain, dexamethasone"s role is not well defined.
 
Dr. Rebecca K. S. Wong from Princess Margaret Hospital, Toronto, Ontario, Canada and colleagues evaluated the effectiveness of prophylactic dexamethasone when added to ondansetron for the control of emesis in patients receiving 15 or more radiation fractions to the upper abdomen. The 211 patients in the study were randomized to ondansetron 8 mg with either dexamethasone 4 mg or placebo daily during days 1 to 5 of fractionated radiotherapy.
 
The addition of dexamethasone appeared to improve the control of nausea without significantly protecting against emesis during fractions 1 to 5, the authors report.

There was also an advantage to dexamethasone treatment during the overall study period, in providing better complete protection against emesis, lowering average nausea scores, and requiring less rescue medication during days 1 to 15, the results indicate.

The combination of ondansetron and dexamethasone was tolerated as well as the combination of ondansetron and placebo, according to the report.
 
Although global quality of life deteriorated with combination or ondansetron-only treatment, the researchers note, the combination treatment was associated with better appetite, better quality of life, and less nausea and vomiting than was ondansetron alone. Sleep and constipation were somewhat worse with the combination treatment.
 
These results support a benefit from adding a short course of dexamethasone to ondansetron for protection against radiation-induced nausea during a fractionated course of radiotherapy, the investigators conclude.

"Although our study did not demonstrate a statistically significant benefit for the primary endpoint (defined as the proportion of patients with complete control of emesis and nausea between days 1 through 5), results on several secondary end points, as well as quality of life data, would suggest that benefits do exist with the addition of dexamethasone," they say.
 
SOURCE:

• J Clin Oncol 2006;24:3458-3464.