Valproic Acid (3 brand names, 3 dosage forms, 1 route)
Available dosage forms: CAPSULE, SYRUP, CAPSULE, DELAYED RELEASE.
Routes of administration: ORAL.
Brand Names
- DEPAKENE
- STAVZOR
- VALPROIC ACID
Related Health Topics
Related Conditions
Contraindications
Valproic acid should not be administered to patients with hepatic disease or significant hepatic dysfunction [see Warnings and Precautions (5.1)] . Valproic acid is contraindicated in patients known to have mitochondrial disorders caused by mutations in mitochondrial DNA polymerase γ (POLG; e.g., Alpers-Huttenlocher Syndrome) and children under two years of age who are suspected of having a POLG-related disorder [see Warnings and Precautions (5.1)] . Valproic acid is contraindicated in patients with known hypersensitivity to the drug [see Warnings and Precautions (5.12)] . Valproic acid is contraindicated in patients with known urea cycle disorders [see Warnings and Precautions (5.6)] . For use in prophylaxis of migraine headaches: Valproic acid is contraindicated in women who are pregnant and in women of childbearing potential who are not using effective contraception [see Warnings and Precautions (5.2, 5.3, 5.4)and Use in Specific Populations (8.1)] .
Adverse Reactions
The following serious adverse reactions are described below and elsewhere in the labeling: Hepatic failure [see Warnings and Precautions (5.1)] Birth defects [see Warnings and Precautions (5.2)] Decreased IQ following in uteroexposure [see Warnings and Precautions (5.3)] Pancreatitis [see Warnings and Precautions (5.5)] Hyperammonemic encephalopathy [see Warnings and Precautions (5.6, 5.9, 5.10)] Suicidal behavior and ideation [see Warnings and Precautions (5.7)] Bleeding and other hematopoietic disorders [see Warnings and Precautions (5.8)] Hypothermia [see Warnings and Precautions (5.11)] Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan hypersensitivity reactions [see Warnings and Precautions (5.12)] Somnolence in the elderly [see Warnings and Precautions (5.14)] Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.
Mechanism of Action
Valproic acid dissociates to the valproate ion in the gastrointestinal tract. The mechanisms by which valproate exerts its therapeutic effects have not been established. It has been suggested that its activity in epilepsy is related to increased brain concentrations of gamma-aminobutyric acid (GABA).
Overdosage
Overdosage with valproate may result in somnolence, heart block, deep coma, and hypernatremia. Fatalities have been reported; however, patients have recovered from valproate levels as high as 2,120 mcg/mL. In overdose situations, the fraction of drug not bound to protein is high and hemodialysis or tandem hemodialysis plus hemoperfusion may result in significant removal of drug. The benefit of gastric lavage or emesis will vary with the time since ingestion. General supportive measures should be applied with particular attention to the maintenance of adequate urinary output. Naloxone has been reported to reverse the CNS depressant effects of valproate overdosage. Because naloxone could theoretically also reverse the antiepileptic effects of valproate, it should be used with caution in patients with epilepsy.