Valproate prevents seizures in most people who use it to
control complex partial seizures and absence seizures. It is also effective
against generalized tonic-clonic seizures, myoclonic seizures, and atonic
Common side effects of valproate include:
Nausea, vomiting, and stomach cramps.
Temporary hair loss.
These side effects may increase as the dosage needed to control
seizures increases. Because valproate levels in the body tend to go up and
down, some side effects may vary from day to day or even within a single day.
Nausea and stomach problems usually go away after the body adjusts to the drug.
Hair loss, weight gain, and tremors often come with long-term use of the
Skin rash, a very common side effect of antiepileptic drugs, is
less common with valproate. Valproate tends to have less effect on your
thinking, memory, or learning processes than other antiepileptic drugs (as long
as the drug levels in your bloodstream do not become too high).
The U.S. Food and Drug Administration (FDA) has issued a warning on
antiepileptic medicines and the risk of suicide and suicidal thoughts. The FDA
does not recommend that people stop using these medicines. Instead, people who
take antiepileptic medicine should be watched closely for
warning signs of suicide. People who take
antiepileptic medicine and who are worried about this side effect should talk
to a doctor.
See Drug Reference for a full list of side effects. (Drug Reference
is not available in all systems.)
What To Think About
It may take time and careful, controlled adjustments by you and
your doctor to find the combination, schedule, and dosing of medicine to best
manage your epilepsy. The goal is to prevent seizures while causing as few
side effects as possible. After you and your doctor figure out the
program that works best for you, make sure to follow your
program exactly as prescribed.
Adverse effects. The weight gain that can result
from use of valproate can be quite significant and is a major concern for
some people. High levels of valproate may also cause severe tremors that
make certain types of work and activities quite difficult.
Serious health risks. Valproate may cause liver
damage (called hepatotoxicity). This liver damage can be fatal, although only
children younger than age 10 have died from it. Children ages 2 and younger who
are taking more than one drug and have other brain and nervous system disorders
are at highest risk. Routine blood tests and careful monitoring can lower the
risk. The risk of liver disorders caused by valproate is extremely low in
Drug interactions. Many medicines for epilepsy can
interact with other medicines you may be taking. This means that your epilepsy
medicine may not work as well, or it may affect the way another medicine that you
are taking works. Some of these interactions can be dangerous. Make sure
to tell your doctor about all the medicines, herbal pills, and dietary
supplements you are taking. Valproate is a good choice for women taking
birth control pills, because it will not reduce the effectiveness of the
Risk of birth defects. All medicines for epilepsy
have some risk of birth defects. But the risk of birth defects needs to be
carefully compared to other risks to the baby if the mother stops taking her
epilepsy medicine. If you are thinking about becoming pregnant, be sure
to plan ahead and talk with your doctor about the benefits and risks of taking
epilepsy medicine during your pregnancy. It you are already pregnant, it is not
too late. The best thing to do is talk to your doctor about your pregnancy
before you make any changes to the medicines you are taking. Your doctor may be especially concerned about valproate use. One study found a link between valproate use during the first trimester and a higher risk of having a baby with birth defects. Pregnant women who used valproate during the first trimester had a higher risk of having a baby with birth defects than pregnant women who took no medicine for their epilepsy or who took a different antiepileptic medicine during the first trimester.2
Other concerns. For some people, valproate may
cause side effects or carry risks that are not yet fully known. Report any
unexpected side effects or problems to your doctor.
Drugs for epilepsy (2008). Treatment Guidelines From The Medical Letter, 6(70): 37–46.
Jentink J, et al. (2010). Valproic acid monotherapy in pregnancy and major congenital malformations. New England Journal of Medicine, 362(23): 2185–2193.
How this information was developed to help you make better health decisions.