Acetyl-L Canitine and Alzheimer’s Disease

Clinical and neurochemical effects of acetyl-L-carnitine in Alzheimer's disease

Pettegrew JW; Klunk WE; Panchalingam K; Kanfer JN; McClure RJ
Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh, School of Medicine, PA 15213, USA.
Neurobiol Aging (UNITED STATES) Jan-Feb 1995, 16 (1) p1-4,

In a double-blind, placebo study, acetyl-L-carnitine was administered to 7 probable Alzheimer's disease patients who were then compared by clinical and 31P magnetic resonance spectroscopic measures to 5 placebo-treated probable AD patients and 21 age-matched healthy controls over the course of 1 year. Compared to AD patients on placebo, acetyl-L-carnitine-treated patients showed significantly less deterioration in their Mini-Mental Status and Alzheimer's Disease Assessment Scale test scores. Furthermore, the decrease in phosphomonoester levels observed in both the acetyl-L-carnitine and placebo AD groups at entry was normalized in the acetyl-L-carnitine-treated but not in the placebo-treated patients. Similar normalization of high-energy phosphate levels was observed in the acetyl-L-carnitine-treated but not in the placebo-treated patients. This is the first direct in vivo demonstration of a beneficial effect of a drug on both clinical and CNS neurochemical parameters in AD.

Acetyl-L-carnitine: A drug able to slow the progress of Alzheimer's disease?

ANN. NEW YORK ACAD. SCI. (USA), 1991, 640/- (228-232)

Defects in cholinergic neurotransmission do not, by themselves, constitute the sole pathophysiologic concomitants of Alzheimer's disease (AD). Recent findings point out that abnormalities in membrane phospholipid turnover and in brain energy metabolism may also characterize AD. Acetyl-L-carnitine (ALC) is an endogenous substance that, acting as an energy carrier at the mitochondrial level, controls the availability of acetyl-L-CoA. ALC has a variety of pharmacologic properties that exhibit restorative or even protective actions against aging processes and neurodegeneration. A review of a series of controlled clinical studies suggests that ALC may also slow the natural course of AD.

Pharmacokinetics of IV and oral acetyl-L-carnitine in a multiple dose regimen in patients with senile dementia of Alzheimer Type

EUR. J. CLIN. PHARMACOL. (Germany), 1992, 42/1 (89-93)

Acetyl-L-carnitine (ALC), a physiological component of the L-carnitine family, has been proposed for treating Alzheimer's disease in pharmacological doses. As this condition requires prolonged therapy, its kinetics has been examined after a multiple dose regimen, involving different routes of administration, in 11 patients suffering from Senile Dementia of Alzheimer Type. The study design comprised a 3-day basal observation period, sham treatment with repeated blood sampling; treatment with 30 mg.kg-1 i.v. given twice for 10 days (plasma kinetics was studied on the 7th day), and 50 days of 2.0 g/day p.o. given in three daily doses. Total acid soluble L-carnitine, L-carnitine and acetyl-L-carnitine in plasma and CSF were evaluated using an enantioselective radioenzyme assay. Short chain L-carnitine esters were calculated as the difference between total and free-L-carnitine. The plasma concentrations of individual components of the L-carnitine family did not change during the three days of the basal period, nor were they affected during the sham therapy period. Following the i.v. bolum injections, the plasma concentrations showed a biphasic curve, with average t(one-half) of 0.073 h and 1.73 h, respectively. At the end of oral treatment, plasma acetyl-L-carnitine and L-carnitine short chain esters were significantly higher than during the run-in phase. The CSF concentrations paralleled those in plasma, suggesting that ALC easily crosses the blood-brain barrier. It is concluded that i.v. and oral administration of multiple doses of ALC can increase its plasma and CSF concentration in patients suffering from Alzheimer's disease.

Double-blind, placebo-controlled study of acetyl-l-carnitine in patients with Alzheimer's disease

CURR. MED. RES. OPIN. (United Kingdom), 1989, 11/10 (638-647)

A randomized, double-blind, placebo-controlled, parallel-group clinical trial was carried out to compare 24-week periods of treatment with 1 g acetyl-l-carnitine twice daily and placebo in the treatment of patients with dementia of the Alzheimer type. A total of 36 patients entered the trial, of whom 20 patients (7 active, 13 placebo) completed the full 24 weeks. Whilst several of the efficacy indices showed little change in either group during the trial, there was an apparent trend for more improvement in the acetyl-l-carnitine group in relation to the Names Learning Test and a computerized Digit Recall Test, both related to aspects of short-term memory. Similarly, there was a trend for reaction time in the computerized classification test to show less deterioration in the active treatment group. Changes within groups, and changes between groups, failed to reach statistical significance, at least partially because of the small number of patients available for analysis. Two indices of overall therapeutic benefit showed a trend for less deterioration in the active-treatment group than in the placebo group. Nausea and/or vomiting occurred in 5 patients in the acetyl-l-carnitine group. Laboratory tests revealed no signs of drug toxicity. The results suggest that acetyl-l-carnitine may have a beneficial effect on some clinical features of Alzheimer-type dementia, particularly those related to short-term memory.