Duration of sweat cyclophosphamide excretion in patients undergoing a conditioning regimen of high-dose cyclophosphamide for hematopoietic stem-cell transplantation.

ABSTRACT

PURPOSE: To investigate the duration of cyclophosphamide (CPA) excretion in the sweat after administration when receiving high-dose CPA therapy as a conditioning regimen for hematopoietic stem-cell transplantation (HSCT). METHODS: Shirts and pillowcases samples (changed once a day) from 12 patients, categorized as groups 1 (n = 6), 2 (n = 4), and 3 (n = 2), receiving high-dose CPA therapy were collected, sealed, stored at 4°C, and mailed to an analytical facility for CPA estimation using LC-MS/MS. CPA was administered intravenously at a dose of 60 mg/kg on days 1, 2 (closed-system delivery for group 3), and samples were collected during days 1-4 (groups 1,3) or days 1-9 (group 2). RESULTS: CPA was detected in all 126 shirts and pillowcases. In 9 patients, excluding 1 patient who had fever during the study period and group 3 patients, the mean (range) rate of CPA excretion in sweat was 0.03% (0.01-0.12%). The mean CPA excretion in 9 patients adjusted for body weight was 19.9 µg/kg on day 1 and 0.3 µg/kg on day 4. CONCLUSIONS: This study showed that CPA was excreted for an extended duration in the patient's sweat, receiving a high-dose CPA therapy as a conditioning regimen against HSCT.