An overview on the use of granisetron in the treatment of emesis associated with cytostatic chemotherapy.

The clinical research programme with granisetron has involved a total of 1,229 patients, 982 receiving granisetron, 233 receiving currently available combination regimens and 14 receiving placebo. The true efficacy of granisetron was evaluated in a placebo-controlled trial with granisetron given prophylactically and being available as rescue medication in the placebo group. Granisetron produced a complete anti-emetic response in 92.9% of patients and was effective as intervention for the emesis experienced by the patients in the placebo group. Dose-finding studies have confirmed the wide therapeutic margin with four-fold increases in dose producing comparable results. In patients receiving high-dose cisplatin chemotherapy, two out of every three patients responded to a single prophylactic dose; which demonstrates granisetron's long duration of action (greater than 24 h). Additional granisetron also demonstrated benefit if the initial dose failed or delayed-onset emesis occurred. These results are also seen with other emetogenic regimens. Granisetron produces a greater degree of control than the anti-emetic combinations of metoclopramide/dexamethasone or dexamethasone/chlorpromazine. The side-effect profile in volunteers was favourable. The profile in patients is more difficult to define due to the range of potent drugs which cancer chemotherapy patients receive. Headache and constipation were the most common effects with granisetron, although the former was treatable with simple analgesics and the latter thought to be related to higher doses and subsided spontaneously. The future is promising, with the possible introduction of a fixed 3 mg i.v. dose administered over 5 min followed by oral maintenance therapy if and when required.