PK and Safety Evaluation of Daptomycin in Children Ages 2-6 With Proven or Suspected Gram-positive Infections

Inclusion Criteria: * Written parental (or appropriate legal representative) informed consent prior to any study-related procedure not part of normal medical care; * Male or female between the ages of 2 and 6 years old, inclusive; * Able to comply with the protocol for the duration of the study; * Clinically stable with no evidence of hemodynamic instability (defined as a requirement for pharmacological intervention to manage blood pressure) in the 72 hour window prior to enrollment, and no history or evidence of renal or hepatic compromise; * Suspected or diagnosed Gram-positive infection for which the subject is receiving standard antibiotic therapy; * A calculated creatinine clearance rate (CLcr) ≥ 80 ml/min/1.73m2 as determined by the Schwartz equation at baseline; * Creatine phosphokinase (CPK) levels less than 2X ULN (upper limit of normal) at baseline. * Presence of two patent intravenous lines (or comparable means of venous access) prior to dosing on Study Day 1. Exclusion Criteria: * Investigational drug use (including daptomycin) or participation in any experimental procedure in the 30 days preceding study entry; * Known allergy/ hypersensitivity to daptomycin; * History of clinically significant cardiovascular, renal, hepatic, pulmonary (well-controlled asthma is acceptable), gastrointestinal, endocrine, hematologic, autoimmune disease or primary immune deficiency; * Pneumonia as sole Gram-positive infection being treated with standard antibiotics; * Subjects with clinically significant abnormal laboratory test results \[including electrocardiograms (ECGs)\], as determined by Investigator; * Administration of rifampin within 7 days of study drug administration; * Body mass index (BMI) that is outside of the 5th to 95th percentile; * Subjects in whom collection of the required blood volume would put them at risk of hemodynamic disturbance (at the discretion of Investigator); * History of or current clinically significant (at the discretion of the Investigator) muscular disease, nervous system or seizure disorder; * Administration of intramuscular injection between baseline and study drug administration or expected intramuscular injection within 24 hours following dosing; * Expected surgical procedure(s) within 24 hours prior to and following dosing; * Unexplained muscular weakness, history of peripheral neuropathy, Guillian-Barre or spinal cord injury; * History of or current rhabdomyolysis.