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How and when to take sodium valproate - Brand names: Dyzantil, Epilim, Episenta, Epival

Sodium valproate is a prescription medicine. It's important to take it as your doctor tells you, or follow the instructions in the leaflet that comes with your medicine.

Dosage and how to take sodium valproate

Dosage

The usual dose of sodium valproate for treating epilepsy in adults and children aged 12 years and over is 600mg to 2,000mg a day, as 1 dose or split into 2 doses. Some people take a higher dose of 2,500mg a day.

For younger children aged 1 month to 11 years, the doctor will use your child's weight to work out the right dose for them.

The usual dose for treating bipolar disorder in adults is 750mg to 2,000mg a day, as 1 dose or split into 2 doses.

The usual dose for preventing migraine in adults is 400mg to 1,500mg, split into 2 doses.

If your doctor tells you to take sodium valproate twice a day, you'll usually take half the dose in the morning and half in the evening (to make up your full daily dose).

If you're taking sodium valproate and have kidney problems, your doctor may prescribe a lower dose.

Changes to your dose

To reduce the chance of side effects, your doctor will start you off on a low dose of sodium valproate. They will increase it gradually over a few days or weeks.

Once you find a dose that suits you, it will usually stay the same, unless your condition changes, or your doctor starts you on a new medicine that may affect sodium valproate.

How to take it

Sodium valproate comes as gastro-resistant tablets, crushable tablets, and as a liquid. It also comes as slow release (also called prolonged or sustained release) tablets, capsules and granules.

Slow release medicine passes into your body gradually.

Gastro-resistant tablets release the medicine as soon as it passes through your stomach. This means the sodium valproate is less likely to upset your stomach.

You can take sodium valproate with or without food, but it's best to stick to the same way each time. Try not to take it with food some days and without food on other days.

How to take slow release tablets and capsules

Swallow these whole with a drink of water or squash. Do not chew them.

You'll usually take them once a day, unless you're on a high dose and your doctor tells you to take your medicine twice a day.

How to take slow release granules

Add the granules to a small drink, then stir and swallow it. If you prefer, sprinkle the granules onto any soft food that you can swallow whole. Do not chew the granules.

Your doctor will tell you to take these either once or twice a day.

How to take gastro-resistant tablets

Swallow these whole with a drink of water or squash. Do not chew them.

You'll usually take these twice a day.

How to take crushable tablets

Crush the tablets using the back of a spoon and mix the powder with some soft food that you can swallow whole. If you prefer, add the powder to a small drink, then stir and swallow it.

You'll usually take this medicine twice a day.

How to take liquid

Use the plastic syringe or spoon that comes with your medicine to measure the correct dose. If you do not have one, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not measure the right amount.

You'll usually take the liquid twice a day.

When to take it

If you're taking sodium valproate once a day, you can choose a time that suits you. Just try to keep to the same time every day.

If you're taking sodium valproate twice a day, try to leave a gap of 10 to 12 hours between doses. For example, you could take your first dose in the morning (between 7am and 8am) and your second dose in the evening (between 7pm and 8pm).

How long to take it for

Once your condition is under control, you'll usually need to keep taking sodium valproate for many years.

Do not stop taking it suddenly, unless your doctor tells you to.

If you forget to take it

If you've missed a dose, what you do next depends on whether you usually take your medicine once or twice a day.

If you take sodium valproate:

  • once a day – take the forgotten dose as soon as you remember unless it's within a few hours of the next dose. In this case, skip the missed dose and take your next dose at the usual time
  • twice a day – take the forgotten dose as soon as you remember unless it's nearly time for the next dose. In this case, skip the missed dose and take your next dose at the usual time

Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.

If you have epilepsy, it's important to take this medicine regularly. Missing doses can trigger a seizure.

If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

If you take too much

Taking too much sodium valproate can cause symptoms such as:

  • feeling or being sick (nausea or vomiting)
  • headaches
  • feeling dizzy
  • muscle weakness
  • breathing problems
  • feeling confused, or changes to your normal behaviour
  • fainting

Urgent advice: Contact 111 for advice now if:

  • you take more than your prescribed dose of sodium valproate and feel unwell

Call 111 or get help from 111 online. Call 111 if you're asking about a child under 5 years old.

Information:

If you need to go to A&E, do not drive. Ask someone to drive you or call 999 and ask for an ambulance.

Bring the sodium valproate packet or leaflet inside it, any remaining medicine, and any other medicines you take.

Page last reviewed: 11 March 2025
Next review due: 11 March 2028