Carnitine deficiency and hyperammonemia associated with valproic acid therapy

Area of Science:

• Biochemistry
• Neurology
• Pharmacology

Background:

• Valproic acid is a widely used anticonvulsant.
• Valproic acid has been associated with metabolic disturbances.
• Carnitine plays a crucial role in fatty acid metabolism and ammonia detoxification.

Purpose of the Study:

• To investigate the effect of valproic acid on plasma carnitine and blood ammonia levels in severely handicapped patients.
• To explore the relationship between valproic acid dosage, plasma carnitine, and blood ammonia.
• To evaluate the efficacy of D,L-carnitine supplementation in correcting these abnormalities.

Main Methods:

• Plasma carnitine and blood ammonia were measured in 25 severely handicapped patients (ages 3-21) and 27 controls.
• Patients were categorized based on valproic acid treatment.
• Biochemical parameters were assessed before and after four weeks of D,L-carnitine (50 mg/kg/day) administration.

Main Results:

• Patients treated with valproic acid exhibited lower plasma carnitine and higher blood ammonia levels compared to controls and untreated patients.
• A significant inverse correlation was observed between valproic acid dosage and plasma carnitine levels.
• A significant inverse correlation was found between plasma carnitine and blood ammonia levels.
• D,L-carnitine supplementation normalized plasma carnitine and blood ammonia levels.

Conclusions:

• Valproic acid therapy is associated with carnitine deficiency and hyperammonemia in severely handicapped patients.
• D,L-carnitine supplementation effectively corrects valproic acid-induced carnitine deficiency and hyperammonemia.
• Carnitine supplementation may be a beneficial therapeutic strategy for patients on valproic acid therapy.