Valproic Acid and Divalproex ... Health Article

Definition

Valproic acid is an anticonvulsant used to control seizures in the treatment of epilepsy, a neurological dysfunction in which excessive surges of electrical energy are emitted in the brain.

Valproic acid is closely related to divalproex sodium and valproate sodium. While these drugs are primarily used in the treatment of epilepsy, divalproex sodium is also indicated for the treatment of manic episodes (abnormally and persistently elevated mood) associated with bipolar disorder.

Purpose

Valproic acid is thought to depress activity in certain areas of the brain, suppressing the irregular firing of neurons to prevent seizures. Divalproex sodium is a stable coordination compound formed with valproic acid.

While valproic acid and divalproex sodium control the seizures associated with epilepsy, there is no known cure for the disease.

Description

In the United States, valproic acid and divalproex sodium are sold under the brand names Depekene and Depakote. Valproic acid is available in tablet and syrup form. Divalproex sodium is available in tablet, injection, or in sprinkle form.

Recommended dosage

Valproic acid usually requires two to four oral doses each day. The typical total daily dose is initiated at 15mg per kilogram (2.2 pounds) of body weight, and is increased in weekly intervals by 5–10 mg per kilogram of body weight until seizures are controlled. The frequency of adverse effects may increase with increasing doses, therefore, changes in dosage are made gradually. It may require several weeks of dosage titration (adjustment for maximum benefit and minimum risk) to realize the full benefits of valproic acid or divalproex sodium.

Persons should not take a double dose of anticonvulsant medications. If a daily dose is missed, it should be taken as soon as possible. However, if it is almost time for the next dose, the missed dose should be skipped.

When discontinuing treatment including valproic acid or divalproex sodium, physicians typically direct patients to gradually reduce their daily dosages. Stopping the medicine suddenly may cause seizures to occur or become more frequent.

Precautions

Persons should avoid alcohol while taking valproic acid or divalproex sodium. It can exacerbate (heighten) the side effects of alcohol and other medications. A physician should also be consulted before taking valproic acid or divalproex sodium with certain non-prescription medications, such as medicines for asthma, appetite control, coughs, colds, sinus problems, allergies, and hay fever.

Valproic acid and divalproex sodium may not be suitable for persons with a history of liver or kidney disease, mental illness, high blood presure, angina (chest pain), irregular heartbeats, or other heart problems. Valproic acid and divalproex sodium may cause liver damage (hepatotoxicity), though the risk is low in adults. The prescribing physician may order routine blood tests to screen for liver damage.

Before beginning treatment with valproic acid or divalproex sodium, patients should notify their physician if they consume a large amount of alcohol, have a history of drug use, are pregnant, or plan to become pregnant.

Valproic acid and divalproex sodium may cause birth defects, and have been linked to an increased risk of spina bifida. Physicians often counsel their patients to use effective birth control while taking either of these medications. Unlike many other anti-convulsant medications, valproic acid will not decrease the effectiveness of oral contraceptives (birth control pills). Patients who become pregnant while taking valproic acid or divalproex sodium should contact their physician immediately.

Side effects

Research indicates that valproic acid and divalproex sodium are generally well tolerated. In certain individuals and especially children under two years of age, however, valproic acid may cause severe damage to the liver or pancreas. It is important to keep all appointments with the physician and laboratory to monitor the body's response to valproic acid. Temporary nausea, vomiting, stomach cramps, weight gain, temporary hair loss, shaking, and an irregular menstrual cycle are the most frequently reported side effects of valproic acid and divalproex sodium. Other possible side effects include:

• nervousness
• anxiety
• difficulty with memory
• double vision
• loss of appetite
• restlessness
• sleepiness or sleeplessness
• unusual drowsiness
• diarrhea or constipation
• heartburn or indigestion
• aching joints and muscles or chills
• unpleasant taste in mouth or dry mouth
• tingling or prickly feeling on the skin

Many of these side effects disappear or occur less frequently during treatment as the body adjusts to the medication.

Other, uncommon side effects of valproic acid and divalproex sodium can be potentially serious. A patient taking valproic acid who experiencs any of the following symptoms should contact their physician:

• jaundice (yellow tone to skin and eyes)
• facial swelling
• persistent fatigue
• rash
• mood or mental changes
• depression
• persistent trembling of the arms and hands
• restlessness
• excessive sleeplessness
• hallucinations
• difficulty breathing
• chest pain
• irregular heartbeat
• faintness
• persistent, severe headaches
• persistent fever or pain.