Metabolism and disposition of intravenously administered acetyl-L-carnitine in healthy volunteers

Eur J Clin Pharmacol. 1989;37(1):59-63. doi: 10.1007/BF00609426.


The pharmacokinetics of acetyl-L-carnitine hydrochloride were investigated in 6 healthy volunteers of both sexes after i.v. injection of 500 mg of the drug, expressed as inner salt. Plasma concentrations and urinary excretion of acetyl-L-carnitine (A), L-carnitine (B) and total acid soluble L-carnitine fraction were evaluated over a period lasting from 24 h before to 48 h after the administration. Plasma concentrations of A increased quickly after administration and then declined reaching base values within 12 h. Conversely, plasma concentrations of B rose more slowly, reaching a peak in 30-60 min, and then declined to base values within 24 h. Most of the injected dose of acetyl-L-carnitine was recovered in the urine during the first 24 h after administration as B and A. Mean renal clearance of both A and B during the first 12 h after injection was higher than the base values, suggesting the presence of a saturable tubular reabsorption process which may counterbalance major changes occurring in plasma concentrations of L-carnitine pattern.

MeSH terms

  • Acetylcarnitine / administration & dosage
  • Acetylcarnitine / metabolism*
  • Acetylcarnitine / pharmacokinetics
  • Adult
  • Carnitine / administration & dosage
  • Carnitine / analogs & derivatives*
  • Carnitine / metabolism
  • Carnitine / pharmacokinetics
  • Female
  • Half-Life
  • Humans
  • Injections, Intravenous
  • Male


  • Acetylcarnitine
  • Carnitine