Valproic Acid: Uses, How to Take & Side Effects

Valproic acid or sodium valproate is an anticonvulsant and mood stabilizer that works by increasing GABA levels in the brain. GABA is a type of neurotransmitter responsible for decreasing the activity of neurons, and low levels are associated with seizures, bipolar disorder or migraines. Valproic acid helps restore the balance of neurons, which is necessary for the proper functioning of the brain.

This medicine can be found in pharmacies and drugstores in the form of tablets, capsules or syrup. It is sold only with a medical prescription.

Valproic acid is found in the form of 250 mg capsules, 300 or 500 mg tablets or in the form of a 50 mg/mL syrup, administered orally. It can also be administered IV in a hospital setting.

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Common uses

Valproic acid is indicated for the treatment of seizures, epilepsy, absence seizures and bipolar disorder. It can also be prescribed to prevent migraine flare-ups. 

Also recommended: Migraines: Symptoms, Causes, Diagnosis & Treatment

How to take

Valproic acid should be taken orally, with a glass of water, in the dose and duration established by the doctor. However, if you forget to take a dose on time, take it as soon as you remember. You should skip the missed dose if it is almost time to take the next dose. Do not double the dose to make up for a forgotten dose.

Dosing for valproic acid, for adults and children over 10 years of age, varies according to the reason it is prescribed:

  • Epilepsy or seizures: the initial dose is 10-15 mg per kg of body weight per day. This dose can be increased to a maximum of 60 mg per kg of body weight per day, according to medical evaluation;
  • Bipolar disorder: the initial dose is 750 mg per day, divided into 2 doses, and can be increased to up to 3000 mg per day or 60 mg per kg of body weight per day, according to medical advice;
  • Migraine: the initial dose is 250 mg, twice a day, and can be increased to a maximum of 500 mg, twice a day.

Valproic acid tablets and capsules can be taken after a meal to avoid stomach irritation, and should be taken whole, without breaking or chewing, as they can cause irritation in the mouth or throat. The syrup has a special formula that does not cause irritation in the mouth or throat and must be taken using the dispenser provided in the packaging.

While using valproic acid, patients should undergo tests that measure platelet levels in the blood, as this medicine can cause a decrease in blood clotting and increase the risk for bleeding.

Possible side effects

Some of the most common side effects that may occur during treatment with valproic acid are nausea, vomiting, stomach pain, diarrhea, drowsiness, feeling weak or dizzy, headaches, tremors, difficulty with motor coordination, blurry vision., hair loss, weight gain or drug-induced hepatitis.

Valproic acid can cause serious allergic reactions that require immediate medical attention. Therefore, you should stop treatment and seek the nearest emergency room if you experience symptoms such as difficulty breathing, coughing, chest pain, a feeling of a closed throat, swelling in the mouth, tongue or face, or hives. 

Although it is not as common, valproic acid can also cause affect the reproductive system. It can cause changes to your period, amenorrhea, dysmenorrhea or menorrhagia, galactorrhea, breast enlargement in men, vaginal bleeding, erectile dysfunction and male infertility.

You should seek immediate medical attention if valproic acid is taken in higher doses than prescribed. Symptoms of overdose include fever, glandular swelling, lumps on the skin, muscle pain, excessive weakness, bleeding, yellowing of the skin or eyes, loss of appetite, stomach pain that radiates to the back, or dark urine.

Furthermore, the doctor should be notified if the person experiences changes in mood or behavior, depression, anxiety, panic attacks, difficulty sleeping or impulsivity, irritation, agitation, aggression or thoughts about suicide.

Contraindications for use

Valproic acid should not be taken by anyone who is allergic to valproic acid. The syrup of this medicine should not be taken by diabetics as it contains sorbitol, a type of sugar that can increase blood glucose.

Additionally, valproic acid should not be taken by:

  • Children under 10 years old
  • Breastfeeding women
  • People taking anticoagulants or anti-inflammatories
  • People with liver problems such as hepatitis or liver failure
  • People with genetic diseases such as urea cycle disorder, porphyria or Alpers-Huttenlocher syndrome

This medicine should not be taken during pregnancy, unless the woman was already using valproic acid before becoming pregnant. The risks and benefits of use should always be evaluated by the doctor, as this medication could harm the fetus. Furthermore, valproic acid can reduce the effect of oral contraceptive pills, and it is recommended to use another method to prevent pregnancy, such as a condom or diaphragm when using this medication.

Other medications can interfere with the action of valproic acid by increasing or decreasing its effect, such as phenobarbital, haloperidol, loxapine, maprotiline or monoamine oxidase inhibitors (MAOIs), such as isocarboxazid, phenelzine, or tranylcypromine.

In addition, vitamins, dietary supplements and herbal products can also interfere with the action of valproic acid. Therefore, it is important to inform the doctor and pharmacist of all medications that you are taking to avoid a decrease or increase in the effect of valproic acid. You should also avoid using any other medication on your own.