5-hydroxytryptamine-3 receptor antagonist with or without short-course dexamethasone in the prophylaxis of radiation induced emesis: a placebo-controlled randomized trial of the National Cancer Institute of Canada Clinical Trials Group (SC19).
OBJECTIVE
To evaluate the effectiveness of prophylactic dexamethasone for the control of radiation induced emesis (RIE) when added to ondansetron during days 1 to 5 of fractionated radiotherapy. The study had two hypotheses: ondansetron and dexamethasone could provide superior control of RIE over ondansetron alone during the prophylactic period and; the combination could provide sustained control of RIE during subsequent fractions of radiotherapy.


METHODS
Between May 2001 to Jan 2004, 211 patients receiving radiotherapy (> or = 15 fractions) to the upper abdomen were randomly assigned to receive ondansetron 8 mg bid with either dexamethasone 4 mg daily or placebo during fractions 1 to 5. Rescue antiemetics were provided.


RESULTS
During the prophylactic period there was a trend for improved complete control of nausea in the dexamethasone arm (50% v 38%; P = .06) while complete and partial control of emesis, average nausea score, and use of rescue medications were similar in the two groups. During the overall study period patients receiving dexamethasone had better complete control of emesis (23% v 12%; P = .02) and a lower average nausea score (0.28 v 0.39; P = .03); there was a trend towards less use of rescue medications with dexamethasone (70% v 80%; P = .09); other outcomes were similar on the two arms. Quality of life analysis showed a significant difference in appetite.


CONCLUSIONS
The addition of dexamethasone to ondansetron as prophylaxis provides a modest improvement in protection against RIE during moderately emetogenic fractionated radiotherapy. It is a potentially useful addition to 5-hydroxytryptamine-3 receptor antagonists in this setting.
National Cancer Institute of Canada Clinical Trials Group, Canada. Rebecca.wong@rmp.uhn.on.ca
Wong
Rebecca K S
RK
Paul
Nancy
N
Ding
Keyue
K
Whitehead
Marlo
M
Brundage
Michael
M
Fyles
Anthony
A
Wilke
Derek
D
Nabid
Abdenour
A
Fortin
Andre
A
Wilson
Don
D
McKenzie
Michael
M
Ackerman
Ida
I
Souhami
Luis
L
Chabot
Pierre
P
Pater
Joseph
J
D000932:Antiemetics / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002170:Canada; D003907:Dexamethasone / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000188:drug therapy / Q000209:etiology; D017294:Ondansetron / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D011788:Quality of Life; D011878:Radiotherapy / Q000009:adverse effects*; D058831:Serotonin 5-HT3 Receptor Antagonists; D012702:Serotonin Antagonists / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D014839:Vomiting / Q000209:etiology / Q000517:prevention & control*
D000932:Antiemetics; D058831:Serotonin 5-HT3 Receptor Antagonists; D012702:Serotonin Antagonists; D017294:Ondansetron; D003907:Dexamethasone