Valproic acid

What it is

Valproic acid is an anticonvulsant that raises brain GABA activity and damps repetitive neuronal firing through effects on sodium channels. It is prescription-only and is used for epilepsy; migraine prevention is an approved indication on the Japanese label, but the Croatian and Czech labels cover epilepsy and bipolar mania only, so there it is off-label. It is taken to prevent episodes, not to relieve one that has already started.

A usual adult range, not a national label — the dose and the timing differ by country and by product.

Used for

• Epilepsy
• Migraine

Approved uses differ by country — some of these may be off-label or unapproved where you live.

What to know while taking it

It is taken with food, which softens the stomach upset it often causes. Liver enzymes, platelets and albumin are watched because the drug can injure the liver, lower platelet counts and displace other drugs from protein binding; it also depletes folate, zinc and selenium over time. Combining it with lamotrigine slows that drug's clearance and raises the risk of a serious rash, and with acetylsalicylic acid it can push free valproate levels and bleeding tendency up. Appetite and weight commonly increase, sometimes substantially, and stopping suddenly can trigger seizures.

When to see a doctor

Yellowing of the eyes or skin, dark urine, persistent vomiting, unusual bruising or bleeding, or sudden drowsiness and confusion call for a doctor without delay. Pregnancy, or planning one, must be discussed with a doctor before anything is changed, since this drug is not used in pregnancy.

Worth knowing

• Not during pregnancy
• Watch liver enzymes
• Can change body weight
• Do not stop abruptly

Markers to watch

• ALT
• AST
• Platelets
• Albumin

Nutrients affected

• vitaminB9 — depleted by (Folate, Hemoglobin, Homocysteine)
• zinc — depleted by (Free T3, Testosterone, TSH)
• selenium — depleted by (Free T3, Free T4, TSH)