L-carnitine supplementation in dialysis: treatment in quest of disease.

L-Carnitine (LC) administration has been recommended for specific indications in dialysis patients, including epoetin-resistant anemia, intradialytic hypotension, cardiomyopathy, fatigue, muscle weakness, and exercise performance; it may ameliorate insulin resistance, inflammation, and protein wasting. Use of LC for anemia and intradialytic hypotension has been approved for reimbursement by the Centers for Medicare and Medicaid Services. Yet, the data to support these recommendations are inadequate and have not been bolstered over several decades. LC administration continues to appeal to nephrologists because its use in dialysis patients has an attractive rationale, it addresses problems that persist despite dialysis, it is safe, and the existing literature does not refute its use. Nevertheless, definitive trials to justify LC administration have not been conducted and are increasingly unlikely to be funded. In an era of shrinking resources and bundling of dialysis services, the use of LC in dialysis patients will, appropriately, diminish.