Daptomycin treatment for persistent bacteremia in a pediatric solid organ transplant recipient: case report and literature review.

INTRODUCTION: Information on the clinical utility of daptomycin in patients with persistent bacteremia and daptomycin's pharmacokinetic data in pediatric patients has been sparse. In addition, reports on the experience of using daptomycin in children undergoing solid organ transplantation have been extremely limited. The authors describe a pediatric case of persistent bacteremia after solid organ transplantation successfully treated by daptomycin. Blood daptomycin concentrations were measured by liquid chromatography-mass spectrometry and pharmacokinetic analysis was performed. We also conducted a literature review on the use of daptomycin in children with persistent bacteremia.

CASE REPORT: An eight-year-old girl who underwent small bowel and liver transplantation experienced persistent bacteremia due to Staphylococcus epidermidis. The bacteremia persisted despite standard therapy; however, it finally resolved with the addition of daptomycin. The patient had renal dysfunction and the initial dosing resulted in excessive drug exposure. The dosage was adjusted based on the pharmacokinetic analysis. The dosage of administrated teicoplanin was also adjusted according to trough concentration values. In the literature review, we identified 12 cases of neonates and 24 cases of post-neonatal children with the experience of using daptomycin for persistent bacteremia; however, no solid organ transplant recipient was identified. Similar trends in blood concentrations and dose ratios of teicoplanin and daptomycin were observed over time.

DISCUSSION: More information is required regarding the clinical utility and pharmacokinetics of daptomycin in pediatric patients with persistent bacteremia. Referring to the exposure to renally excreted drugs that are routinely measured and pharmacokinetic analysis of daptomycin may be useful in optimizing the dose of daptomycin in special patient populations, including those with renal impairment.