1. ¹Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
2. ²Department of Pharmacy, The Hospital for Sick Children, Toronto, Ontario, Canada
3. ³Division of Haematology/Oncology, The Hospital for Sick Children, Toronto, Ontario, Canada
4. ⁴Division of Critical Care Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
5. ⁵Research Institute, University of Toronto, Toronto, Ontario, Canada
6. ⁶Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada

Correspondence: LL Dupuis, Department of Pharmacy, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8. E-mail: lee.dupuis@sickkids.ca

Received 9 November 2007; Revised 7 May 2008; Accepted 15 May 2008; Published online 14 July 2008.

Abstract

In solid organ transplantation, CYA dosing is based on the area under the concentration vs time curve (AUC_inf). This study aimed to develop a guideline for the initial i.v. CYA dose for pediatric hematopoietic SCT (HSCT) patients to achieve the target AUC_inf recommended in solid organ transplantation. Whole-blood CYA concentrations were determined in 24 patients (0.5–16.9 years) after the first i.v. dose given over 2 h, 1 day before HSCT. The i.v. CYA dose predicted to achieve an AUC_inf of 4200 g h/l was calculated for each patient and expressed as a function of each patient's actual weight and body surface area (BSA). In patients 9 and >9 years of age, the mean i.v. CYA dose predicted to achieve the target AUC was 2.60.94 and 2.11.21 mg/kg, respectively. When these doses were expressed in terms of BSA, the mean dose was 6523.1 and 6835.0 mg/m² in children 9 and >9 years of age, respectively. In children 0.5–17 years of age undergoing HSCT, we recommend an initial i.v. CYA dose of 65 mg/m² infused over 2 h to achieve an AUC_inf of approximately 4200 g h/l.