Daptomycin Pharmacokinetics in Adolescents Undergoing Hemodialysis and Peritoneal Dialysis: A Case Series With Pharmacokinetic Modeling.

Background: Children who undergo hemodialysis (HD) and peritoneal dialysis are at increased risk of infection. Daptomcyin is used to treat resistant infections; however, the pharmacokinetics of daptomycin in pediatric and adolescent dialysis patients remain unknown.

Methods: We report the safety and pharmacokinetics of a single intravenous 5 mg/kg dose of daptomycin for 6 individuals age 12 to 17 years old who underwent HD or continuous cycling peritoneal dialysis (CCPD). Daptomycin concentrations from all samples were determined by high-performance liquid chromatography. A non-compartmental analysis was performed to compare the pharmacokinetic parameters among HD and CCPD patients. A population pharmacokinetic model was developed to describe the concentration-time profiles of daptomycin in plasma, urine, and dialysis effluent. Monte Carlo simulations were performed to assess the pharmacodynamic outcomes.

Results: All subjects tolerated the single dose of daptomycin. During HD, significant drug removal was observed, compared with CCPD (26% vs 5% of total dose). A low daptomycin renal clearance (<12% of total clearance) with moderate variability (40.5%) was observed among subjects with residual renal function. An anuric and obese subject who received CCPD treatment appeared to have >80% higher daptomycin area under the plasma concentration-time curve than the other CCPD subjects. Dosing regimens that achieved predefined pharmacodynamic targets were reported.

Conclusions: Daptomycin clearance was faster in 12- to 17-year-old patients receiving HD than CCPD. Administration of daptomycin immediately after HD reduces drug loss. The CCPD treatment, anuria, and obesity may increase the risk for drug accumulation. Our pharmacokinetic model can be further used to optimize dosing regimens of daptomycin in this population.