Intravenous and Oral Posaconazole Pharmacokinetics in a Five-Year-Old With Mucor: A Case Report and Review of the Literature

Posaconazole is a lipophilic triazole antifungal that exhibits variable absorption when administered orally. It possesses a broad spectrum of activity against various fungi, such as Aspergillus and traditionally resistant molds such as Rhizopus and Mucor, which carry a poor prognosis. Unfortunately, the tablet and suspension formulations of posaconazole are Food and Drug Administration approved for treatment of fungal diseases only in patients older than 13 years of age. Furthermore, the approval of the IV formulation is exclusively for adult patients. Nevertheless, the extended spectrum of activity and available dosage forms make it an attractive option for pediatric use. The data that exist to guide dosing of posaconazole in young pediatric patients are limited primarily to case series and case reports. Thus, we recommend therapeutic drug monitoring to ensure both safety and efficacy in pediatric patients. Herein we describe our experience with both oral and IV posaconazole in the salvage therapy of a 5-year-old female with extensive cutaneous Mucor. In contrast to previous reports, which show larger doses may be necessary to obtain therapeutic concentrations in pediatric patients as compared with adults, our patient reached targeted concentrations with weight-based dosing.