Granisetron reduces postoperative nausea and vomiting throughout menstrual cycle

The incidence of postoperative nausea and vomiting (PONV) is influenced by menstruation. This study was undertaken to assess the efficacy of granisetron, a selective 5-hydroxytryptamine type 3 receptor antagonist, for preventing PONV in patients during two different phases of menstrual cycle.

One hundred twenty female patients undergoing general anaesthesia for major gynaecological surgery were divided according to the phase of menstrual cycle into two groups: day one to eight (menstrual) and day nine to end of the cycle (non-menstrual) groups. In a randomized, double-blind manner, the patients received placebo (saline) or 40 micrograms.kg-1 granisetron i.v. immediately before the induction of anaesthesia. All patients received a standardized general and epidural anaesthesia and epidural morphine plus bupivacaine for postoperative analgesia. The incidence of PONV and other adverse events was recorded during the first 24 hr after anaesthesia.

The treatment groups were similar with respect to patient demographics, types of surgery, anaesthetics administered and analgesics used postoperatively. The incidence of PONV was 72% and 32% in patients during menstruation receiving placebo or granisetron (P < 0.05), and was 46% and 20% in those during non-menstruation, respectively (P < 0.05). No differences in the incidence of other adverse events were observed among the groups.

Granisetron was effective in reducing the incidence of PONV in both phases of the menstrual cycle studied.