Valproic acid belongs to the class of medications called anticonvulsants. It is used for the management and control of certain types of seizures. It works on the central nervous system (CNS) in the brain to reduce the number and severity of seizures.

Your doctor may have suggested this medication for conditions other than the ones listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

The recommended dose of valproic acid is based on body weight. The dose of medication is usually started at a low level and increased gradually to reduce side effects. The final dose is determined by the control of seizures with a minimum of side effects. Capsules should be swallowed whole and can be taken with food to avoid stomach upset.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important that this medication be taken exactly as prescribed by the doctor. Don't stop taking this medication without talking to your doctor. If you miss a dose, take it as soon as possible and continue on with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue on with your regular dosing schedule. Do not double doses.

Depakene^® is available in capsule and liquid form.

Capsules:
250 mg: Each orange-coloured, soft gelatin capsule contains valproic acid 250 mg. Nonmedicinal ingredients: corn oil, ethyl vanillin, FD&C Yellow No. 6, gelatin, glycerin, methylparaben, propylparaben, and titanium dioxide.
500 mg: Each pale yellow, oval, soft gelatin enteric-coated capsule contains valproic acid 500 mg. Nonmedicinal ingredients: cellulose acetate phtalate, dextrose, diethyl phtalate, ethyl acetate, gelatin, glycerin, methylparaben, propylparaben, tartrazine, and titanium dioxide.

Liquid: Each 5 mL of red syrup contains 250 mg valproic acid. Nonmedicinal ingredients: artificial flavour, glycerin, hydrochloric acid, methylparaben, propylparaben, red amaranth Canadian certified food colour, sodium hydroxide, sorbitol, sucrose, and vanillin.

This medication does not contain alcohol, gluten, lactose, sulfite, or tartrazine.

Valproic acid should not be taken by anyone with:

• liver disease or significant reduction in liver function
• an allergy to valproic acid or to any of the ingredients of the medication

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor. Your health professional may be able to help you deal with some of the effects.

The following side effects may go away as your body becomes used to the medication; check with your doctor if they continue or become bothersome.

More common:

• abdominal or stomach cramps (mild)
• change in menstrual periods
• diarrhea
• hair loss
• indigestion
• loss of appetite
• nausea and vomiting
• trembling of hands and arms
• unusual weight loss or gain

  Less common or rare:

• clumsiness or unsteadiness
• constipation
• dizziness
• drowsiness
• headache
• skin rash
• unusual excitement, restlessness, or irritability

Check with your doctor as soon as possible if any of the following side effects occur:

Less common:

• abdominal or stomach cramps (severe)
• behavioural, mood, or mental changes
• continuous, uncontrolled "back and forth" or rolling eye movements
• double vision
• increase in seizures
• loss of appetite
• nausea or vomiting (continuing)
• spots before eyes
• swelling of face
• tiredness and weakness
• unusual bleeding or bruising
• yellow eyes or skin

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Blood clotting: This medication may make it more difficult for the blood to clot. People taking anticoagulant medications (blood-thinning medications) should take appropriate precautions and ensure that all doctors involved in their care are aware of all medication use. Tests for blood clotting take place before any surgery. Platelet count and coagulant tests should take place before starting treatment with valproic acid.

Kidney function: Reduced kidney function increases the risk of overdose with this medication. Caution and close monitoring of kidney function is required.

Liver: Liver failure has occurred infrequently for people taking valproic acid. This has usually occurred during the first six months of treatment. Children under two years of age who took valproic acid together with other epilepsy medications are at greatest risk (nearly 20 times greater) of developing serious liver problems. These children typically had other medical conditions such as congenital metabolic disorders, mental retardation, or organic brain disease. Liver function tests should take place before starting treatment with valproic acid.

Serious liver problems may be preceded by symptoms such as loss of seizure control, malaise, weakness, lethargy, loss of appetite, and vomiting. People who take valproic acid should tell their doctor at once if they experience these symptoms. Increases in the levels of ammonia in the blood, with or without lethargy or coma, have been reported and may be present despite normal liver function tests.

Occupational hazards: People who take valproic acid are advised not to engage in potentially hazardous activities such as driving a car or operating machinery until they determine that they do not become drowsy as a result of taking this medication.

Pancreatitis: Cases of life-threatening pancreatitis have been reported for both children and adults. These have occurred either shortly after beginning the medication or after several years of use. Symptoms that suggest pancreatitis include abdominal pain, nausea, vomiting, or anorexia. These symptoms require prompt medical attention.

Sedation: Valproic acid may cause sedation, especially when combined with another sedating drug such as alcohol.

Pregnancy: People who need medications to prevent major seizures should not stop taking them. Prior to or during pregnancy, women who need medications to prevent minor seizures should weigh the risks of discontinuing the medication against the risks to the child. Women with epilepsy who may become pregnant should speak to their doctor about this issue; they should contact their doctor immediately if they become pregnant.

Breast-feeding: Valproic acid passes into breast milk. As a general rule, women who are taking valproic acid should not breast-feed.

Children: If valproic acid is taken by children two years old or younger, it should be used with extreme caution and as a single medication. The benefits of seizure control should be weighed against the risk.

• ASA
• carbamazepine
• chlorpromazine
• cimetidine
• clonazepam
• felbamate
• lithium
• MAO inhibitors
• phenobarbital
• phenytoin
• primidone
• rifampin
• SSRIs
• tolbutamide
• tricyclic antidepressants

Valproic acid may affect how the following work:

• alcohol
• ASA
• benzodiazepines (e.g., diazepam, lorazepam)
• carbamazepine
• clonazepam
• ethosuximide
• lamotrigine
• phenobarbital
• phenytoin
• primidone
• tolbutamide
• warfarin
• zidovudine

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. In many cases, interactions are intended or are managed by close monitoring. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.