Summary:Considerable progress has been made in improving the control of chemotherapy-induced emesis. The impact of available antiemetic options for patients receiving stem cell transplants is unclear, as few prospective data have been collected. We prospectively evaluated antiemetic outcome in patients receiving stem cell transplantation over a 7-day period following the initiation of chemotherapy. The primary endpoints were the number of emetic episodes and the extent of nausea measured on a four-point scale. Eighty-two patients were evaluated. Ninety-five percent of patients had nausea during the first week of treatment; 80% had at least one emetic episode. The percentage of patients with emesis was as follows: day 1: 13%, day 2: 21%, day 3: 30%, day 4: 38%, day 5: 44%, day 6: 39%, day 7: 18%. In multivariate analysis, gender, emesis with prior chemotherapy, history of morning or motion sickness, type of transplant (auto vs allo), use of total body irradiation, or use of dexamethasone did not effect emesis control. Most patients receiving high-dose chemotherapy experience incompletely controlled emesis. Control of nausea and emesis progressively worsened with each subsequent day following initiation of chemotherapy, reaching a nadir on day 5. New treatment approaches are needed to improve emesis control in this patient population. Bone Marrow Transplantation (2001) 28, 1061-1066. Keywords: nausea; bone marrow transplantation Myeloablative chemotherapy and radiotherapy followed by autologous or allogeneic stem cell transplantation have been shown to be curative for certain hematologic malignancies, aplastic anemia, and genetic disorders. 1-3 Over the last three decades of transplantation, there have been significant advances in supportive management to lessen tox- icity and improve tolerance of autologous and allogeneic stem cell transplantation. [4][5][6][7] From the patient's standpoint, two of the most feared adverse effects of chemotherapy are treatment-induced nausea and vomiting. 8,9 Considerable progress has been made in the control of nausea and vomiting for patients receiving standard doses of chemotherapy. The use of 5-hydroxytryptamine-3 (5HT3) antagonists, such as dolasetron, granisetron and ondansetron, have contributed significantly to the control of nausea and vomiting in patients receiving moderately and highly emetogenic chemotherapy. [10][11][12][13] The great majority of patients receiving emetogenic chemotherapy at standard doses should achieve complete control of emesis at the present time.A number of patient and treatment-related factors predictive for the development of chemotherapy-induced emesis have been defined. These include age, gender, ethanol consumption history, and the intrinsic emetogenicity of the chemotherapy agents. 14 Also of importance is chemotherapy dose. The emetogenicity of a number of chemotherapy agents such as cisplatin and cyclophosphamide increases with increasing dose. 15 The outcome of antiemetic therapy has not been well studied in the setting of highdose chemo...