Study of the Pharmacokinetics of Daptomycin in Children With Renal Disease

Inclusion Criteria: * Children who are between 12-17 years of age who are either on HD or PD and whom the Pediatric Nephrology Section of the OU Children's Physicians Clinics provide care. * In addition to children on chronic HD and PD therapy, patients newly initiated on HD and PD will also be recruited for this study. * Patients with suspected or confirmed cases of dialysis related infection from gram-positive bacteria and who are receiving standard of care antibiotics. * Patients will be eligible for enrollment if they were admitted as an inpatient to the Children's hospital or as an outpatient to the dialysis clinic Exclusion Criteria: * Patients \> 17 years of age * Patients \< 12 years of age * Total amount of blood drawn as part of standard of care and for pharmacokinetic analysis exceeds 3 ml/kg over an 8 week period * Taking an HMG CoA reductase inhibitor within 7 days of daptomycin administration * Having used daptomycin in the 30 days preceding study entry * Participating in any experimental procedure in the 30 days preceding study * A history of muscular disease or neurological disease * Baseline creatine phosphokinase (CPK) values equal to or greater than 1.5 times the upper limit of normal (normal range 65-370 IU/L) * Hemoglobin \< 9 g/dl * Hemodynamic instability within 72 hours before study enrollment * Female subjects with a positive pregnancy test or failure to take a pregnancy test