Many children with end stage renal disease develop hyperlipidemia. HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase inhibitors, such as pravastatin, are typical treatments for hyperlipidemia. However, we do not know how pravastatin is metabolized in patients on dialysis. This study is designed to provide preliminary pharmacokinetic data for pravastatin in pediatric patients on peritoneal dialysis.