Future prospects for granisetron.

It has long been recognized that delayed emesis can be difficult to control. As many as 90% of patients receiving high-dose cisplatin regimens ( 120 mg/m2) are reported to experience delayed nausea or vomiting despite antiemetic prophylaxis with high-dose metoclopramide and dexamethasone on the day of cisplatin treatment. The incidence of symptoms is greatest between 48 and 72 hours after cisplatin administration5 and relates to the initial dose of cisplatin. Granisetron has been shown to provide good control over cisplatin-induced emesis in the first 24 hours of treatment with a single prophylactic dose of 40 pg/kg or 160 pg/kg. Of 549 patients so treated, 59% experienced nothing more than mild nausea within the first 24 hours.“2 However, without further doses of granisetron, 62% of patients went on to experience delayed symptoms at some point during the 6-day follow-up period. It is generally thought that the better the acute control of emesis, the less likelihood there is of delayed emesis. This approach is now under investigation, and the efficacy of oral follow-up doses of granisetron in prolonging the blockade of 5-HT3 receptor is being defined. The benefit of the addition of dexamethasone to granisetron on the first day of treatment is also being explored.