Management of carnitine deficiency in ESRD patients undergoing dialysis: Challenges and considerations

Carnitine deficiency is well described in end-stage renal disease (ESRD) patients undergoing dialysis. In 1994, the American Association of Kidney Patients (AAKP) Carnitine Renal Dialysis Consensus Group developed guidelines regarding patient types that would be suitable to receive levocarnitine (L-carnitine) supplementation. The AAKP consensus group reviewed the literature on L-carnitine usage and concluded, based on 42 published studies involving approximately 600 hemodialysis patients, that there is a definite role for L-carnitine in the treatment of renal dialysis patients. The clinical efficacy and safety of L-carnitine in hemodialysis patients are shown in this review. The AAKP Consensus group recommended that patients with the following conditions who don't respond to standard therapy should be given 20 mg/kg of IV L-carnitine following each hemodialysis session: cardiomyopathy, skeletal muscle weakness/myopathy, anemia of uremia unresponsive to or requiring large doses of Epogen(R), lack of energy (which has a negative effect on quality of life), severe and persistent muscle cramps, and/or hypotensive episodes during dialysis. In December 1999, the U.S. Food and Drug Administration (FDA) approved Carnitor(R) (levocarnitine) Injection for the prevention and treatment of carnitine deficiency in patients with ESRD who are undergoing dialysis. The National Kidney Foundation's Kidney disease Outcomes Quality Initiative (K-DOQI) Clinical Practice Guidelines for Nutrition in Chronic Renal Failure published guidelines in 2000 stating that the most promising application for carnitine therapy is for the treatment of erythropoietin-resistant anemia. The K-DOQI Nutrition Workgroup believes that there is insufficient evidence to support the routine use of levocarnitine for maintenance dialysis patients. However, a trial of L-carnitine may be considered in selected individuals who manifest symptoms such as malaise, muscle weakness, intradialytic cramps and hypotension, and poor quality of life who have not responded to standard therapy. In this paper patient selection algorithms used in identifying patients for L-carnitine therapy and evaluating their response to therapy are presented. This approach serves to enhance the interpretation of the K-DOQI guidelines and to identify challenges to achieving desired outcomes of IV L-carnitine therapy.