Nausea and vomiting during post-transplantation cyclophosphamide administration

Post-transplantation cyclophosphamide (PTCy) is a new method to prevent graft-versus-host disease after allogeneic hematopoietic cell transplantation. Although the use of dexamethasone is recommended as prophylaxis against chemotherapy-induced nausea and vomiting (CINV) for patients who receive high-dose cyclophosphamide, corticosteroids cannot be used during PTCy administration to exploit depletion of alloreactive T cells. Thus, CINV may not be adequately controlled in this situation. We retrospectively examined antiemetic efficacy of the combination of a 5-hydroxytryptamine-3 receptor antagonist (5-HT₃ RA) and a NK₁ receptor antagonist (NK₁ RA) in 36 patients who received PTCy, and compared this efficacy with that of the same combination together with dexamethasone in 27 patients conditioned with cyclophosphamide and total body irradiation (CY/TBI). The proportion of patients who had no vomiting during the acute phase of PTCy administration was 81%, and was lower than 100% in the CY/TBI group (p = 0.02). Our results suggest that prevention of CINV using 5-HT₃ RA and NK₁ RA during PTCy administration is suboptimal and that addition of antiemetic is necessary in patients who receive PTCy.