The anti-emetic efficacy of tropisetron plus dexamethasone in patients treated with high-dose chemotherapy and stem cell transplantation

Among the most distressing symptoms experienced by patients who have undergone high-dose chemotherapy and stem cell transplantation are nausea and vomiting. The chemotherapy regimens used in high-dose conditioning protocols are highly emetogenic. The 5HT(3) receptor antagonists are very effective in the prevention and abolition of nausea and vomiting resulting from chemotherapeutic drugs. One of them, tropisetron, is a selective antagonist of serotonin 5HT(3) receptors with proven efficacy against emesis. Dexamethasone is also known as an effective agent against nausea and vomiting. The addition of dexamethasone to a 5HT(3) receptor antagonist is synergistic, as has been shown in many trials with highly emetogenic drugs. The aim of the present trial was to study the efficacy and safety profile of the combination of tropisetron and dexamethasone in controlling nausea and vomiting in patients receiving megatherapy prior to stem cell transplantation. We studied 31 patients. All of them were evaluable for response and toxicity. The majority of patients achieved complete or major protection against acute vomiting (71-83%), and 67-84% of the patients had no or mild nausea. The combination was tolerated well, and only a minority of patients reported side effects. Among them the most common were headache (in three patients) and constipation. No patient withdrew from the study because of toxicity. It has become evident from our data that the administration of 5 mg tropisetron daily in combination with 20 mg dexamethasone for 8 days can prevent the acute emesis otherwise experienced by patients receiving high-dose chemotherapy as conditioning in stem cell transplantation programmes.