[Appropriate dosing of fosaprepitant for colon cancer patients]

After fosaprepitant (FOS)was added to the National Health Insurance drug reimbursement price list, we switched the route of administration of antiemetics from oral to intravenous in chemotherapy regimens for colon cancer to improve patient medication adherence. However, because the number of patients reporting application-site disorders after administration of FOS increased, we monitored the incidence of these disorders in patients with colon cancer to identify ways to avoid them. In our prospective study, patients receiving conventional FOS dosing regimens (control group)were compared with those receiving diluted FOS solutions (study group). There were no significant differences between the two groups with respect to the incidence of application-site disorders, and contrary to expectations, the incidence was higher in the study group than in the control group. On the basis of the principle of non-maleficence and the availability of alternative therapies using oral aprepitant (APR), we terminated this study early and adopted the basic strategy that all patients with application-site disorders, except for those with central venous access devices, should be treated with oral APR after confirming their preferences.