Valoate

Indications

Sodium Valproate is used to treat:

• Epilepsy: many types of seizures (fits) in adults and children, on its own or with other medicines.
• Mania in bipolar disorder (a condition with episodes of very high mood), when other treatments are not suitable.
• Sometimes, prevention of migraine in adults, under specialist advice.

How It Works

It increases the level of GABA, a natural calming chemical in the brain, and steadies nerve cell activity. This helps prevent the abnormal electrical bursts that cause seizures and helps stabilise mood.

Dosage and Administration

The dose is set by the doctor and started low, then increased slowly over days to weeks until seizures or symptoms are controlled; children are dosed by weight. Take exactly as prescribed, usually in one or two doses a day, with or after food. Swallow modified-release tablets whole; do not crush or chew them. Injections are given by a doctor or nurse in hospital. Never stop suddenly, as seizures may return.

Interactions

• Carbapenem antibiotics (such as Meropenem and Imipenem) can sharply lower valproate levels and cause seizures.
• It raises Lamotrigine levels, increasing the risk of serious skin rash; the Lamotrigine dose must be reduced.
• Phenytoin, Carbamazepine, Phenobarbital, Topiramate and other epilepsy medicines can change levels or increase side effects such as high ammonia.
• Aspirin and Warfarin can increase bleeding risk.
• Oestrogen-containing contraceptives can lower valproate levels.
• Alcohol increases drowsiness and liver risk.

Contraindications

• Allergy to valproate.
• Active liver disease, or a personal or family history of severe liver problems, especially if caused by medicines.
• Porphyria, urea cycle disorders, or mitochondrial disease (such as POLG disorders).
• Pregnancy, and girls and women who could become pregnant, unless there is no other suitable treatment and strict pregnancy prevention rules are followed (see below).

Side Effects

Common: nausea, stomach upset, weight gain, increased appetite, hair thinning, shaking (tremor), drowsiness, and changes in periods.

Get urgent medical help for: yellow skin or eyes, dark urine, repeated vomiting, loss of appetite or unusual tiredness (possible liver damage); severe stomach pain spreading to the back (possible pancreatitis); unusual bruising or bleeding; confusion or extreme drowsiness; increased seizures; a severe skin rash; or any thoughts of harming yourself.

Pregnancy and Lactation

Valproate taken during pregnancy carries a high risk of serious birth defects and of learning and developmental problems in the child. Girls and women who could become pregnant should only take it when no other treatment works, must use effective contraception, and should have regular reviews with a specialist. If you are taking it and plan a pregnancy or become pregnant, do not stop it yourself; contact your doctor urgently. Men taking valproate who plan to father a child should discuss this with their doctor. Small amounts pass into breast milk; the doctor will advise, and the baby should be watched for yellowing or bruising.

Precautions and Warnings

• Blood tests for liver function and blood counts are needed, especially in the first 6 months.
• Children under 3 years, and people taking several epilepsy medicines, have a higher risk of liver damage.
• Tell your doctor before any surgery or dental work.
• Do not drive or operate machines if you feel drowsy or your seizures are not controlled.

Overdose

Overdose can cause deep drowsiness, confusion, low blood pressure, breathing problems and coma. This is an emergency; get medical help immediately.

Therapeutic Class

Antiepileptic (valproate) and mood stabiliser.

Storage

Store below 30°C in a dry place, in the original pack to protect from moisture and light, and out of the reach of children.