Methods
One hundred pediatric patients with myocarditis were enrolled. Blood samples were collected at baseline and, approximately 30, 40 or 50, 75 and 180 min after a single dose of phosphocreatine sodium. Plasma PCr and Cr concentrations were determined using a HPLC-MS/MS method. A nonlinear mixed-effects model approach was used to build the population pharmacokinetic model. After validation, the model was used for simulations to evaluate the PK profile of different dosing schemes.