Carnitine Deficiency and Benefits of Its Supplementation in Pediatric Hemodialysis Patients

Patients on hemodialysis (HD) often have carnitine deficiency due to multiple factors; dietary intake of carnitine is decreased due to falls in appetite, total energy levels, and protein intake. In addition, accumulating evidence has linked inflammation to malnutrition, and chronic inflammation might also interrupt carnitine transfer in the intestine. Carnitine biosynthesis can also fall in patients on dialysis due to reduced biosynthesis in the kidney and limited compensation by the liver. Furthermore, because of the low molecular weight of carnitine and its high hydrophilicity and absence of protein binding, carnitine is significantly removed by the dialyzer. As in the healthy population, carnitine deficiency in patients receiving maintenance dialysis is most commonly defined as a serum free carnitine level less than 20 μmol/L .

Intravenous levocarnitine is commonly used to treat patients receiving maintenance hemodialysis who are diagnosed with carnitine deficiency since it has 100%bioavailability and does not break down into toxic metabolites. A common dose used for carnitine supplementation is 10-20 mg/kg administered after each hemodialysis session, which produces the supraphysiologic serum levels of carnitine that are required to adequately drive carnitine from the serum into skeletal muscles.

There are four principal indications for levocarnitine treatment in dialysis patients with carnitine deficiency according to the American National Kidney Foundation: (1) erythropoiesis stimulating agents resistant anemia that has not responded to the standard erythropoiesis stimulating agent dosage; (2) recurrent symptomatic hypotension during hemodialysis;(3) symptomatic cardiomyopathy or confirmed cardiomyopathy with reduced left ventricular ejection fraction and(4) fatigability and muscle weakness that undermine the quality of life.