Valproic acid

Seizure Disorders

Valproic acid is used to treat several types of epilepsy. It may be prescribed alone or in combination with other anti-seizure medications. It is specifically indicated for:

• Complex partial seizures: Seizures that occur by themselves or in association with other types of seizures.
• Absence seizures: Simple and complex absence seizures, which involve brief lapses in consciousness.

Bipolar Disorder

This medication is used to treat the manic phase of bipolar disorder. During these episodes, individuals may experience periods of abnormally high energy, impulsivity, or an elevated mood. Valproic acid helps stabilize these symptoms.

Migraine Prevention

Valproic acid is used to help prevent migraine headaches from occurring. It is important to note that this medication is intended for long-term prevention and is not used to treat a migraine headache that has already begun.

Mechanism of Action

Valproic acid belongs to a class of medications known as anticonvulsants or antiepileptics. Although the exact way it works in the body is not completely understood, researchers believe it primarily affects the balance of neurotransmitters, which are chemical messengers in the brain.

Increasing GABA Levels

One of the main ways valproic acid is thought to work is by increasing the amount of gamma-aminobutyric acid (GABA) in the brain. GABA is an inhibitory neurotransmitter, meaning its job is to reduce or calm the activity of nerve cells. By increasing GABA levels, the medication helps to:

• Control Seizures: It reduces the excessive and abnormal electrical signals in the brain that cause seizures.
• Stabilize Mood: In conditions like bipolar disorder, it helps manage the manic phase by regulating brain activity.
• Prevent Migraines: It helps decrease the frequency of migraine headaches, likely by reducing the excitability of the nervous system.

Because the medication affects the central nervous system, it helps restore a more normal balance of electrical activity, though the specific biological pathways continue to be studied by medical researchers.

Common Side Effects

Many people using valproic acid experience mild side effects as their bodies adjust to the medication. These may include:

• Nausea, vomiting, or stomach pain
• Diarrhea or constipation
• Changes in appetite or weight
• Drowsiness, dizziness, or weakness
• Tremors or shaking
• Temporary hair loss
• Blurred or double vision
• Unusual taste in the mouth
• Coordination problems

Serious Side Effects

Some side effects can be severe and require immediate medical attention. Contact a healthcare provider right away if you experience:

• Signs of liver damage, such as yellowing of the skin or eyes (jaundice), dark urine, facial swelling, or loss of appetite
• Severe pain in the upper stomach that spreads to the back, which may indicate pancreatitis
• New or worsening depression, anxiety, or suicidal thoughts and behaviors
• Unexplained fever, sore throat, or easy bruising and bleeding
• Confusion, extreme tiredness, or vomiting, which may be signs of high ammonia levels in the blood
• A significant drop in body temperature (hypothermia)
• Severe skin reactions, including a rash, peeling, or blisters

Boxed Warnings

Valproic acid has several boxed warnings due to the risk of severe or life-threatening conditions:

• Liver Failure: Severe liver damage, which can be fatal, has occurred. This risk is highest during the first six months of treatment. Children under the age of two are at the greatest risk, especially if they take multiple seizure medications or have certain metabolic disorders.
• Pancreatitis: Life-threatening inflammation of the pancreas has been reported in both children and adults. This can occur shortly after starting the medication or after several years of use.
• Fetal Harm: Exposure to this medication during pregnancy can cause serious birth defects, such as neural tube defects, and may lead to lower IQ scores in the child. It is generally not recommended for use during pregnancy unless other treatments are ineffective.

Mental Health and Behavior

Like other antiepileptic drugs, valproic acid may increase the risk of suicidal thoughts or behaviors. Changes in mood, new or worsening depression, or anxiety should be monitored closely by healthcare providers and caregivers.

Blood and Metabolic Concerns

• Hyperammonemia: High levels of ammonia in the blood can occur, which may lead to brain dysfunction (encephalopathy). This risk is higher in individuals with urea cycle disorders or when taken with certain other medications.
• Bleeding Risks: The medication can cause a decrease in blood platelets, which may lead to easy bruising or unusual bleeding.
• Hypersensitivity: Serious multi-organ reactions, such as Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), can occur and require immediate medical attention.

Mitochondrial Disorders

Individuals with certain genetic mitochondrial disorders, such as Alpers-Huttenlocher syndrome, are at an increased risk for acute liver failure and should typically avoid this medication.

Pregnancy Risks

Valproic acid can cause serious birth defects if taken during pregnancy. These defects often occur early in the first trimester, sometimes before a person knows they are pregnant. Potential risks include:

• Neural tube defects: Such as spina bifida, where the spinal cord or brain does not develop properly.
• Physical malformations: Including defects of the face, skull, heart, and limbs.
• Developmental issues: Children exposed to valproic acid in the womb may have a higher risk of lower IQ scores and neurodevelopmental disorders, such as autism.

For the prevention of migraine headaches, valproic acid should not be used by pregnant individuals or those planning to become pregnant. For conditions like epilepsy or bipolar disorder, it is typically only used during pregnancy if other medications have failed to control symptoms or are otherwise unsuitable.

Breastfeeding Considerations

Valproic acid passes into breast milk in small amounts. While it is often considered compatible with breastfeeding, there are potential risks to the infant, such as liver toxicity or changes in blood cell counts. Healthcare providers typically recommend monitoring the infant for any unusual symptoms if breastfeeding while taking this medication.

Contraception and Planning

Individuals of childbearing age should use effective birth control while taking valproic acid. If pregnancy is planned or occurs unexpectedly, it is critical to contact a healthcare provider immediately. Do not stop taking the medication without medical guidance, as uncontrolled seizures or mood episodes can also pose significant risks to both the parent and the fetus.

Available Forms

Valproic acid is available in various formulations to treat different conditions and patient needs. These include:

• Oral Capsules: Standard capsules and delayed-release sprinkle capsules, which can be opened and sprinkled onto soft food.
• Oral Tablets: Available as delayed-release and extended-release tablets. Extended-release versions are typically taken once daily, while delayed-release versions may be taken more frequently.
• Oral Liquid: A syrup or solution form for patients who have difficulty swallowing solid dosage forms.
• Injection: An intravenous (IV) solution administered by a healthcare professional, usually in a hospital setting when oral medication is not an option.

The medication is also available as divalproex sodium, a related compound that the body converts into valproic acid. Divalproex sodium is commonly found in delayed-release and extended-release formats to help manage how the drug is absorbed and to potentially reduce stomach-related side effects.

FDA-Approved Indications

The U.S. Food and Drug Administration (FDA) has approved valproic acid and its related compounds (such as divalproex sodium) for several specific medical conditions:

• Seizure Disorders: It is used as both monotherapy and adjunctive therapy for complex partial seizures and simple or complex absence seizures.
• Bipolar Disorder: It is approved for the treatment of manic episodes associated with bipolar disorder.
• Migraine Prophylaxis: It is indicated for the prevention of migraine headaches, though it is not approved for the acute treatment of an active migraine.

Boxed Warnings

Valproic acid carries several boxed warnings, the most serious type of warning required by the FDA, due to the risk of severe adverse reactions:

• Hepatotoxicity: Hepatic failure resulting in fatalities has occurred. This risk is highest in children under two years of age and patients with mitochondrial disorders. Liver function must be monitored closely.
• Fetal Risk: The drug can cause major congenital malformations, particularly neural tube defects like spina bifida. It is also linked to decreased IQ scores and neurodevelopmental disorders in children exposed during pregnancy.
• Pancreatitis: Cases of life-threatening pancreatitis have been reported in both children and adults, sometimes occurring shortly after starting the medication or after several years of use.

Regulatory Safety Communications

The FDA has issued specific safety communications regarding the use of valproate products in women of childbearing age. Because of the significant risks to a developing fetus, the FDA states that valproic acid should not be used for migraine prevention in pregnant women. For those with epilepsy or bipolar disorder, it should only be used during pregnancy if other medications have failed to provide adequate symptom control.

Risks of Sudden Discontinuation

It is critical not to stop taking valproic acid suddenly without consulting a doctor. Abruptly ending treatment can cause a severe, long-lasting, and potentially life-threatening type of seizure known as status epilepticus. This risk exists even if you feel well or believe the medication is no longer necessary.

The Importance of Tapering

If a decision is made to stop the medication, healthcare providers typically recommend a gradual reduction in dosage. This tapering process helps to:

• Prevent seizures from returning.
• Reduce the risk of seizures becoming more frequent or severe.
• Allow the body to adjust safely to the change in medication levels.

Managing Side Effects and Mood Changes

Some patients may feel the urge to stop the medication due to side effects or changes in mood and behavior. However, stopping the drug without medical supervision in these instances can still trigger dangerous seizure activity. If you experience concerning side effects, contact your healthcare provider to discuss a safe plan for adjusting your treatment.