Metabolism and disposition of intravenously administered acetyl-L-carnitine in healthy volunteers.
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.
Marzo
A
A
Real srl, Drug Metabolism and Pharmacokinetics Laboratory, Villaguardia, Como, Italy.
Arrigoni Martelli
E
E
Urso
R
R
Rocchetti
M
M
Rizza
V
V
Kelly
J G
JG
D000108:Acetylcarnitine / Q000008:administration & dosage / Q000378:metabolism* / Q000493:pharmacokinetics; D000328:Adult; D002331:Carnitine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism / Q000493:pharmacokinetics; D005260:Female; D006207:Half-Life; D006801:Humans; D007275:Injections, Intravenous; D008297:Male
D000108:Acetylcarnitine; D002331:Carnitine