Levo-carnitine (L-carnitine) is a naturally occurring quaternary ammonium compound biosynthesized from the amino acids lysine and methionine. It is an essential cofactor in the mitochondrial transport of long-chain fatty acids for beta-oxidation, a critical process for cellular energy (ATP) production. In the Indian context, it is widely used as a nutritional supplement and therapeutic agent for conditions associated with carnitine deficiency, fatigue, and metabolic support.
Adult: Therapeutic (for deficiency): 990 mg to 1980 mg per day in 2-3 divided doses. Nutritional Supplementation: 330 mg to 990 mg once or twice daily.
Note: Oral: Take with or without food. Taking with meals may reduce potential gastrointestinal upset. Capsules/Tablets should be swallowed whole with a glass of water. Do not crush or chew sustained-release formulations.
L-carnitine's primary role is to facilitate the transport of long-chain fatty acids (LCFAs) across the inner mitochondrial membrane. It acts as a substrate for carnitine palmitoyltransferase I (CPT I) on the mitochondrial outer membrane, forming acylcarnitine esters. These esters are then shuttled across the inner membrane via carnitine-acylcarnitine translocase (CACT). Inside the mitochondrial matrix, carnitine palmitoyltransferase II (CPT II) regenerates free carnitine and releases the fatty acyl-CoA for beta-oxidation, the process that generates acetyl-CoA, NADH, and FADH2 for ATP production via the electron transport chain.
Pregnancy: Category B: Animal reproduction studies have not shown a risk, but no adequate, well-controlled studies in pregnant women. Use only if clearly needed. Carnitine is a natural substance and crosses the placenta.
Driving: No known effects on driving ability. However, if dizziness or restlessness occurs, caution is advised.
| Valproic Acid / Valproate | Valproic acid depletes carnitine levels. L-carnitine is used to treat and prevent this deficiency and associated hepatotoxicity. | Major |
| Warfarin | Theoretical interaction; L-carnitine may potentiate anticoagulant effect. Monitor INR closely when starting or stopping L-carnitine. | Moderate |
| Thyroid Hormones (Levothyroxine) | L-carnitine may inhibit the peripheral action of thyroid hormone. Monitor thyroid function in patients on both. | Moderate |
| Acitretin | May increase risk of myalgias. Significance unclear. | Minor |