BMA Concise Guide to Medicine & Drugs

Sodium Valproate (Valproate)

Brand names Convulex (valproic acid), Depakote, Epilim, Epilim Chrono, Epilim Chronosphere, Episenta, Epival

Used in the following combined preparations None

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Drug group Anticonvulsant drug

Overdose danger rating Medium

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Sodium valproate is an anticonvulsant drug that is effective in treating all forms of epilepsy. The action of sodium valproate is similar to that of other anticonvulsants, reducing electrical discharges in the brain to prevent the excessive build-up of discharges that can lead to epileptic seizures.

Beneficial in long-term treatment, this drug does not usually have a sedative effect. This makes it particularly suitable for children who suffer either from atonic epilepsy (the sudden relaxing of the muscles throughout the body) or from absence seizures (during which the person appears to be daydreaming).

Care should be taken if changing between preparations.

Sodium valproate is also sometimes used for the treatment of manic episodes and, in the long-term, for bipolar disorder (manic depression).

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets, MR tablets, capsules, liquid, injection.

Frequency and timing of doses 1–2 x daily, after food.

Dosage range 600mg–2.5g daily, adjusted as necessary.

Onset of effect Within 60 minutes.

Duration of action 12 hours or more.

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children. Protect from light.

Missed dose Take as soon as you remember. If your next dose is due within 2 hours, take a single dose now and skip the next.

Stopping the drug Do not stop the drug without consulting your doctor; symptoms may recur.

Exceeding the dose An occasional unintentional extra dose is unlikely to cause problems. Large overdoses may lead to coma. Notify your doctor.

POSSIBLE ADVERSE EFFECTS

Most of the adverse effects of sodium valproate are uncommon and the most serious ones are rare. They include liver failure, and platelet and bleeding abnormalities. Menstrual periods may become irregular or cease altogether. The drug may also cause temporary hair loss, weight gain, nausea, and indigestion; discuss with your doctor if any of these are severe. If a rash, drowsiness, jaundice, or unusual bruising or bleeding occur, consult your doctor immediately.

INTERACTIONS

Other anticonvulsant drugs may reduce blood levels of sodium valproate.

Zidovudine When zidovudine and sodium valproate are taken together, the blood levels of zidovudine may increase, leading to increased adverse effects.

Lamotrigine Sodium valproate increases levels of lamotrigine and may lead to increased adverse effects.

Carbapenems These antibacterial drugs reduce the blood level of sodium valproate; concomitant use should be avoided.

Antidepressants, antipsychotics, mefloquine, and chloroquine may reduce the effectiveness of sodium valproate to prevent seizures.

Clarithromycin and erythromycin may increase the effects of sodium valproate.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have long-term liver or kidney problems.

· You have porphyria.

· You have any blood disorders.

· You are pregnant or intend to become pregnant.

· You are taking other medicines.

Pregnancy Not recommended. May cause abnormalities in the unborn baby. If sodium valproate is essential, extra folic acid supplements must also be taken. Discuss with your doctor.

Breast-feeding The drug passes into the breast milk, but at normal doses adverse effects on the baby are unlikely. Discuss with your doctor.

Infants and children Reduced dose necessary. The dose is often based on the weight of the child.

Over 60 Reduced dose may be necessary.

Driving and hazardous work Your underlying condition, as well as the possibility of reduced alertness while taking sodium valproate, may make such activities inadvisable. Discuss with your doctor.

Alcohol Avoid. Alcohol may increase the sedative effects of this drug.

PROLONGED USE

Use of this drug can, very rarely, cause liver damage, which is more likely in the first 6 months of use.

Monitoring Periodic blood tests of liver function and blood composition may be carried out.