[Recent improvements in antiemetic therapy]

In the past few years important progress in the prevention of chemotherapy-induced nausea and vomiting has been made mainly thanks to the introduction of the 5-HT3 receptor antagonists in clinical practice (ondansetron, granisetron, tropisetron). In the prevention of acute emesis induced by cisplatin, an intravenous combination of a 5-HT3 receptor antagonist plus single dose dexamethasone (20 mg) should be considered the treatment of choice. This is also the case in the prevention of acute emesis induced by moderately emetogenic chemotherapy (intravenous cyclophosphamide, doxorubicin, epirubicin, carboplatin, used alone or in combination), but high and repeated doses of dexamethasone should be used (8 mg intravenously plus 4 mg orally every 6 hours for four doses starting contemporarily to chemotherapy administration). Several-well conducted double-blind comparative studies among intravenously administered 5-HT3 receptor antagonists have been carried out. Almost all showed that they have identical antiemetic activity and tolerability. Therefore, the choice among 5-HT3 receptor antagonists should be based only on their acquisition cost in each country. In the prevention of delayed emesis (from day 2 to day 4) induced by cisplatin oral metoclopramide (0.5 mg/kg or 20 mg every 6 hours for four doses daily) and oral ondansetron (8 mg twice daily), both combined with dexamethasone, showed similar antiemetic efficacy. Metoclopramide plus dexamethasone should be considered the antiemetic regimen of choice due to its lower cost. Ondansetron plus dexamethasone is a valid alternative regimen that should be preferred in patients who not tolerate metoclopramide and in patients who suffer from acute vomiting. In the prevention of delayed emesis induced by moderately emetogenic chemotherapy oral dexamethasone or oral ondansetron showed a good antiemetic efficacy, but the results from a recently published study seem suggest the necessity to treat only patients who present acute vomiting or moderate-severe nausea. In fact, patients obtaining complete protection from vomiting and nausea (or at most mild acute nausea) have a very low incidence of delayed emesis.