Valproic Acid

Brand names

• Alti-Valproic
• Apo-Divalproic
• Apo-Valproic
• Atemperator
• Depa
• Depakene
• Depakote
• Deproic
• Epival
• Myproic
• Novo-Divalproex
• Novo-Valproic
• Nu-Valproic
• PMS-Valproic Acid E.C.
• Rhoproic
• Valproic

Usage

To control certain types of seizures in the treatment of epilepsy and other disorders. Also used to treat acute mania in the treatment of bipolar disorder.

How it works

Valproic acid is thought to depress the activity of certain parts of the brain and suppress the abnormal firing of neurons that causes seizures.

Side effects

Serious

Severe abdominal pain and vomiting, muscle weakness and lethargy, yellow discoloration of the skin or eyes, facial swelling, abnormal bleeding or bruising, or seizures may be a sign of liver failure or other potentially fatal complications.

Common

Nausea and vomiting, heartburn, diarrhea, cramps, loss of appetite and weight loss, increased appetite and weight gain, hair loss, tremor, dizziness, clumsiness or unsteadiness, confusion, sedation.

Less common

Drowsiness, restlessness, constipation, unusual excitability, skin rash, headache, blurred or double vision, irritability or other changes in mental state. There are numerous additional side effects; consult your doctor if you are concerned about any adverse or unusual reactions.

Possible interactions

Other medicaments:

Valproic acid may increase the effects of:

• anticoagulants (Coumadin, etc.) and increase the risk of bleeding; increased frequency of INR (prothrombin time or protime) testing is needed.
• antidepressants (both monoamine oxidase [MAO] type A inhibitors and tricyclics) and cause toxicity.
• benzodiazepines (such as alprazolam).
• nimodipine (Nimotop) and cause nimodipine toxicity.
• phenobarbital and cause barbiturate intoxication.
• phenytoin (Dilantin) or fosphenytoin (Cerebyx) and cause phenytoin or fosphenytoin toxicity. .
• zidovudine (AZT) and may lead to zidovudine toxicity.

Valproic acid taken concurrently with:



• acyclovir (Zovirax) may lower valproic acid levels.
• antacids (Maalox) will decrease absorption and lower therapeutic benefits of valproic acid.
• antiplatelet medicaments-aspirin, dipyridamole (Persantine), sulfinpyrazone (Anturane)-may enhance the inhibition of platelet function and increase the risk of bleeding.
• aspirin can lead to valproic acid toxicity.
• carbamazepine (Tegretol) may have a variable effect on blood levels; more frequent blood level testing is advised.
• cholestyramine (various) may blunt valproic acid benefits.
• clonazepam (Klonopin) may result in repeated episodes of absence seizures.
• cyclosporine (Sandimmune) may increase risk of liver toxicity.
• erythromycin (Ery-Tab, others) may increase the level of valproic acid and result in toxicity; the newer macrolides (azithromycin or clarithromycin) may also cause problems.
• felbamate (Felbatol) can lead to increased valproic acid levels.
• isoniazid (INH) can cause valproic acid or isoniazid toxicity.
• rifampin (Rifater) may lead to valproic acid toxicity.
• ritonavir (Norvir) can lead to loss of valproic acid benefits.

Herbal medicines or minerals:

Using kola or ma huang may result in unacceptable central nervous system stimulation. Valerian and kava kava may interact to increase drowsiness. St. John's wort may also cause increased sun sensitivity-caution is advised. Replacement of zinc and selenium is prudent. Carnitine replacement (intravenous) is needed in valproic acid caused (induced) liver toxicity and overdose. Carnitine replacement may also be needed in infants and young children taking multiple seizure medicines as well as epileptic patients on a ketogenic diet.

Beverages:

Do not administer the syrup in carbonated beverages; this could liberate the valproic acid and irritate the mouth and throat.

Alcohol:

Alcohol can increase the sedative effect of this medicament. Also, this medicament can increase the depressant effects of alcohol on brain function.

Exposure to sun:

This medicament has caused photosensitivity.

Discontinuation:

Do not stop this medicament suddenly. Abrupt withdrawal can cause repetitive seizures that are difficult to control.