Prophylactic antiemetic therapy with granisetron in women undergoing thyroidectomy

We have evaluated the efficacy and safety of granisetron, a selective 5-hydroxytryptamine type-3 receptor antagonist, for the prevention of postoperative nausea and vomiting (PONV) in women undergoing thyroidectomy. In a prospective, randomized, placebo-controlled, double-blind study, 100 ASA I patients, aged 30-57 yr, received placebo or granisetron at three different doses (20, 40 or 100 micrograms kg-1) (n = 25 each), i.v., immediately before induction of anaesthesia. A standard general anaesthetic technique was used. A complete response, defined as no PONV and no need for another rescue antiemetic during the first 3 h after anaesthesia, was seen in 36%, 44%, 92% and 92% of patients who received placebo, granisetron 20 micrograms kg-1, 40 micrograms kg-1 and 100 micrograms kg-1, respectively; corresponding values during the next 21 h after anaesthesia were 40%, 44%, 88%, and 88% (P < 0.05; overall Fisher's exact probability test). There were no clinically important adverse events in any group. We conclude that granisetron 40 micrograms kg-1 was an effective antiemetic for the prevention of PONV after thyroidectomy. Increasing the dose to 100 micrograms kg-1 provided no further benefit.