Bernardo VA, Cross SJ, Crews KR, Flynn PM, Hoffman JM, Knapp KM, Pauley JL, Molinelli AR, Greene WL. Posaconazole therapeutic drug monitoring in pediatric patients and young adults with cancer.
Ann Pharmacother 2013;
47:976-83. [PMID:
23737511 DOI:
10.1345/aph.1r775]
[Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND
Limited information exists regarding the use of posaconazole for treating systemic fungal infections in children, adolescents, and young adults with cancer. At St. Jude Children's Research Hospital, the recommended posaconazole dose in patients weighing less than 34 kg is 18-24 mg/kg daily, given in 4 divided doses. For patients aged 13 years or older or those weighing 34 kg or more, the recommended dose is 800 mg daily, given orally in 4 divided doses.
OBJECTIVE
To determine whether the current posaconazole dosing guidelines achieve target posaconazole plasma concentrations of 0.7 μg/mL or greater.
METHODS
This retrospective clinical study examined data from patients who received treatment-dose posaconazole and had at least 1 posaconazole plasma concentration measurement.
RESULTS
Data from 33 patients who received posaconazole for the treatment of fungal infections were analyzed. The median age of patients was 11.5 years (range 0.5-23.2). Twenty-one of 33 patients (63.6%) had posaconazole concentrations of 0.7 μg/mL or greater (median 1.4; range 0.7-2.98) at the first measurement. The median posaconazole dosage referenced to total body weight in these patients was 20 mg/kg/day. Patients with concentrations less than 0.7 μg/mL (median 0.4; range 0.025-0.69) received lower posaconazole dosages when referenced to body weight (median 12.9 mg/kg/day; p = 0.02). Of the 12 patients with concentrations less than 0.7 μg/mL, 7 (58.3%) were aged 13 years or older.
CONCLUSIONS
The current dosing approach for posaconazole yielded therapeutic plasma concentrations more frequently in patients younger than 13 years than in those 13 years or older. This difference may be related to the practice of capping adolescent and young adult doses at the suggested maximum adult daily dose. Therefore, we recommend weight-based dosing in all pediatric, adolescent, and young adult patients with cancer, with routine therapeutic drug monitoring to ensure adequate concentrations.
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