“…Naguib et al [58] have evaluated the effectiveness of ondansetron 4 mg, granisetron 3 mg, and tropisetron 5 mg, compared with placebo, for the prevention of PONV after laparoscopic cholecystectomy, and demonstrated no difference in the number of patients who were emesis-free during 24 h after anesthesia among the ondansetron, granisetron, and tropisetron groups. In the treatment of established PONV, Alon et al [59] have compared the efficacy and tolerability of three doses (0.5, 2, and 5 mg) of i.v. tropisetron, and have determined that tropisetron 2 mg is the optimal dose.…”