The actions of ondansetron and dexamethasone to antagonise cisplatin-induced emesis in the ferret.

The ability of ondansetron and dexamethasone to antagonise cisplatin 10 mg/kg i.p. induced emesis was investigated in the ferret during a 24 h period. Ondansetron 0.5-5 mg/kg, as a single injection, effectively antagonised the response for approximately 4 h and revealed a subsequent response that was sensitive to further ondansetron treatment. The three times per day administration of dexamethasone 1 mg/kg i.p. alone or combined with ondansetron 1 mg/kg i.p. significantly reduced the vomiting response by 49 and 79%, respectively. The results are discussed in terms of their relevance to acute and delayed emesis in man.