Sodium valproate: medicine to treat epilepsy and bipolar disorder

1. About sodium valproate

Sodium valproate is used to treat epilepsy and bipolar disorder.

It's occasionally used to prevent migraine headaches.

This medicine is only available on prescription. It comes as capsules, tablets and a liquid that you swallow. It also comes as granules that you mix with food or drink.

Sodium valproate can also be given by injection, but this is usually only done in hospital.

If taken during pregnancy, sodium valproate can cause problems for a baby's development, including birth defects and lifelong learning difficulties. Sodium valproate is not recommended if there's a chance that you could become pregnant.

For women and girls of childbearing age, if you do need to take sodium valproate then your doctor will enrol you on Prevent, the valproate pregnancy prevention programme.

For men taking sodium valproate, your fertility could be affected. It may also cause learning or behavioural problems in your child if your partner becomes pregnant while you're taking sodium valproate.

Important: Valproate pregnancy prevention programme

The valproate pregnancy prevention programme is very important.

You should be reviewed every year by your doctor or nurse. They will assess whether you need to continue taking sodium valproate or whether it is possible to change your medicine.

If you need to continue sodium valproate then you must be using reliable contraception, even if you are not currently sexually active. Your doctor or nurse can advise you about reliable contraception. You will be asked to sign a form to say that you are using contraception and understand the risks of becoming pregnant while taking sodium valproate.

It's important to get advice as soon as possible if you think you are pregnant or might become pregnant while taking sodium valproate. However, do not stop taking sodium valproate suddenly without talking to your doctor first.

For men who could possibly have children, it's important to discuss sodium valproate with your doctor. You and your partner should consider using contraception while you're taking sodium valproate and for at least 3 months after stopping.

For men who are planning to start a family within the next year, speak to a doctor about your treatment options. Do not stop taking sodium valproate without speaking to a doctor first.

Updated: 23 February 2024

2. Key facts

You'll usually take sodium valproate once or twice a day. You can take it with or without food.
You'll usually start on a low dose. Your dose will gradually increase over a few days or weeks.
Valproic acid and semisodium valproate are similar to sodium valproate and work in the same way. However these medicines are used to treat different conditions and doses will vary.
There are also brands such as Epilim Chrono, Epilim Chronosphere and Dyzantil which contain mostly sodium valproate, with some valproic acid.
If you're pregnant, or there's a chance you could become pregnant, sodium valproate is not recommended for treating migraine. For epilepsy and bipolar disorder, your doctor will only prescribe sodium valproate for you if there are no other suitable treatments.

3. Who can and cannot take sodium valproate

Sodium valproate can be taken by adults and children to treat epilepsy or bipolar disorder.

It can be taken by adults (aged 18 and above) to help prevent migraine.

Sodium valproate is not suitable for girls or women who could become pregnant. However, in some cases it may be the only treatment option available, for example for epilepsy where other treatments have not worked. Girls and women who need to take sodium valproate must be enrolled on Prevent, the valproate pregnancy prevention programme.

Sodium valproate may affect fertility in men. There may also be a small chance of learning or behavioural problems in the baby if you are taking sodium valproate and your partner becomes pregnant. For these reasons, doctors may recommend different treatments for men who could possibly have children, or in those planning to try for a baby.

To make sure sodium valproate is safe for you, tell your doctor if you:

have ever had an allergic reaction to sodium valproate or any other medicine
have liver problems
have a rare metabolic or genetic illness such as porphyria, urea cycle disorder or mitochondrial disorder

4. How and when to take sodium valproate

Sodium valproate is a prescription medicine. It's important to take it as your doctor tells you.

Dosage

The usual dose for treating epilepsy in:

adults and older children (aged 12 years and over) – 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
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 – 750mg to 2,000mg a day, as 1 dose or split into 2 doses
children – the doctor will work out the right dose for your child

The usual dose for preventing migraine in:

adults – daily doses vary from a single dose of 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.

How to take it

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

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. Do not 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 juice. 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 juice. 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. Do not use a kitchen teaspoon as you will not get the right amount.

You'll usually take the liquid twice a day.

When to take sodium valproate

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).

Will my dose go up or down?

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.

What if I 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 within 2 hours of 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.

What if I take too much?

Taking too much sodium valproate can lead to symptoms such as:

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

Urgent advice: Contact 111 for advice now if:

you take too much sodium valproate and feel unwell

Go to 111.nhs.uk or call 111.

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.

5. Side effects

Like all medicines, sodium valproate can cause side effects, although not everyone gets them.

Common side effects

These common side effects may happen in more than 1 in 100 people. They're usually mild and go away by themselves.

Keep taking the medicine but talk to your doctor if these side effects bother you or do not go away:

stomach pain, feeling or being sick
diarrhoea
dry or sore mouth, or swollen gums
shakes (tremors) in a part of your body, or unusual eye movements
feeling tired or sleepy
headache
weight gain
thinning hair, or changes to the colour or texture of your hair
irregular or delayed periods

Serious side effects

It's unusual to have serious side effects after taking sodium valproate. Tell a doctor straight away if you have:

thoughts of harming or killing yourself – a small number of people taking sodium valproate have had suicidal thoughts
yellowing of the whites of your eyes or your skin, although this may be less obvious on brown or black skin, and dark pee – these may be signs of liver problems
long-lasting and severe nausea, vomiting or stomach pain – these may be signs of acute pancreatitis (an inflamed pancreas)
unusual bruises or bleeding – these may be signs of a blood disorder

Serious allergic reaction

In rare cases, sodium valproate may cause a serious allergic reaction (anaphylaxis).

Immediate action required: Call 999 now if:

your lips, mouth, throat or tongue suddenly become swollen
you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
your throat feels tight or you're struggling to swallow
your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
you suddenly become very confused, drowsy or dizzy
someone faints and cannot be woken up
a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)

You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.

These can be signs of a serious allergic reaction and may need immediate treatment in hospital.

Do not drive yourself to A&E.

The person you speak to at 999 will give you advice about what to do.

These are not all the side effects of sodium valproate. For a full list, see the leaflet inside your medicine packet.

Reporting side effects

You can report any suspected side effect using the Yellow Card safety scheme.

Visit the Yellow Card website for more information about reporting side effects.

6. How to cope with side effects of sodium valproate

What to do about:

stomach pain, feeling or being sick – take sodium valproate with or after a meal or snack. It may also help if you avoid rich or spicy food. Take small, frequent sips of water if you're being sick to avoid dehydration. If you take the combined contraceptive pill or progestogen-only pill and you are sick (vomit), your contraception may not protect you from pregnancy. Check the pill packet for advice.
diarrhoea – drink plenty of fluids such as water or squash to avoid dehydration. Speak to a pharmacist if you have signs of dehydration, such as peeing less than usual or having dark, strong-smelling pee. If you take the combined contraceptive pill or progestogen-only pill and you have severe diarrhoea for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.
dry or sore mouth, or swollen gums – for a dry mouth try sugar-free gum or sweets, or sipping cold drinks. If this does not help, or you have mouth ulcers, talk to your pharmacist or doctor. If you're bothered by swollen gums or this symptom does not go away, talk to your doctor or dentist.
shakes (tremors) in a part of your body, or unusual eye movements – talk to your doctor if this is bothering you. These symptoms can be a sign that your dose is too high. Talk to your doctor as they may want to change your dose or suggest you take it at a different time.
feeling tired or sleepy – as your body gets used to sodium valproate, these side effects should wear off. If these symptoms do not get better within a week or two, your doctor may either reduce your dose or increase it more slowly. If that does not work, talk to your doctor as they may want to switch you to a different medicine.
headaches – make sure you rest and drink plenty of fluids. Try not to not drink too much alcohol. Ask your pharmacist to recommend a painkiller. Talk to your doctor if your headaches last longer than a week or are severe.
weight gain – if you find you're putting on weight after taking sodium valproate, try to have a healthy balanced diet. Regular exercise will also help you keep your weight stable. Your doctor will usually monitor your weight while you're taking this medicine. Speak to them if you have any concerns.
thinning hair, or changes to the colour or texture of your hair – if these symptoms bother you, ask your doctor whether it's possible to lower your dose. Your hair may regrow after either reducing your dose or switching to a different medicine.
irregular or delayed periods – if you usually have regular periods, take a pregnancy test if your period is late, and speak to your doctor if the result is positive. As well as being a side effect of sodium valproate, a late period is a sign that you could be pregnant, and sodium valproate can be harmful for an unborn baby. Changes to your periods can also be a symptom of polycystic ovary syndrome (PCOS), a rare side effect of sodium valproate. Your doctor will be able to do some tests to check whether you have PCOS.

7. Pregnancy and breastfeeding

Sodium valproate and pregnancy

Sodium valproate is not recommended in pregnancy, as it can cause birth defects and problems with your baby's learning and behaviour.

If there's a chance you could become pregnant while taking this medicine, your doctor will enrol you on Prevent, the valproate pregnancy prevention programme.

If you think you might be pregnant and you're taking sodium valproate, contact your doctor or nurse as soon as possible.

If you're taking sodium valproate for epilepsy or bipolar disorder and you become pregnant, do not stop taking your medicine without talking to your doctor first. This is because your symptoms may get worse.

Your doctor may continue to prescribe sodium valproate, but only if there's no other suitable treatment for your epilepsy or bipolar disorder.

For pregnant women with recurrent migraine your doctor should offer you an alternative treatment to sodium valproate.

For men who are planning to start a family within the next year, speak to a doctor about your treatment options. Do not stop taking sodium valproate without speaking to a doctor first.

You must have a review of your treatment every year. Contact your doctor or specialist now if you have not had one.

Sodium valproate and breastfeeding

If your doctor or health visitor says your baby is healthy you can take sodium valproate while breastfeeding.

Sodium valproate passes into breast milk in small amounts but it's unlikely to harm your baby so you can continue breastfeeding if your doctor says you need to take it.

If there's a chance you could become pregnant while taking this medicine, your doctor will put you on Prevent, the valproate pregnancy prevention programme. Your doctor may still recommend sodium valproate if it is the only medicine that works for you.

Do not stop taking your medicine without talking to your doctor first as your symptoms may get worse. Breastfeeding will also benefit both you and your baby.

Talk to your health visitor, midwife, pharmacist or doctor as soon as possible if:

your baby is not feeding as well as usual
your baby is bruising more easily than usual
the whites of your baby's eyes turn yellow or your baby's skin turns yellow (this may be less obvious on brown or black skin), or your baby has dark pee or pale poo – these can be signs of jaundice

Non-urgent advice: Tell your doctor if you're:

trying to get pregnant
pregnant
breastfeeding

More information

8. Cautions with other medicines

There are some medicines that may affect how sodium valproate works. Sodium valproate can also affect the way other medicines work.

Tell your doctor if you're taking any of these medicines:

any other medicines for epilepsy such as carbamazepine
medicines for preventing blood clots such as warfarin
aspirin for pain relief or low-dose aspirin
cimetidine, a medicine for stomach ulcers
medicines to treat HIV and AIDS such as ritonavir
antibiotics such as erythromycin
medicines for depression or other mental health problems such as venlafaxine, quetiapine or diazepam
cholesterol-lowering medicines such as cholestyramine
medicines to prevent malaria such as mefloquine or chloroquine

Mixing sodium valproate with herbal remedies or supplements

It's not possible to say whether complementary medicines and herbal supplements are safe to take with sodium valproate.

They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.

Important: Medicine safety

Tell your doctor or pharmacist if you're taking any other medicines, including herbal medicines, vitamins or supplements.

9. Common questions about sodium valproate

How does sodium valproate work?

Sodium valproate is an anticonvulsant (or anti-epileptic) medicine. It prevents epileptic seizures by reducing excessive electrical activity in your brain.

It's not fully understood how this medicine works for treating bipolar disorder. However, sodium valproate is thought to reduce or prevent manic episodes by increasing the amount of a chemical called gamma-aminobutyric acid (GABA) in the brain. GABA blocks transmission across nerves in the brain and has a calming effect.

It's not clear how sodium valproate prevents migraine. It may limit how your nerves transmit pain signals in the brain.

When will I feel better?

It takes a few weeks for sodium valproate to work properly. You may still have symptoms during this time.

How long will I take it for?

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

Can I get addicted to sodium valproate?

Sodium valproate is not known to be addictive.

Is it safe to take it for a long time?

Many people can take sodium valproate safely for many months or years.

However, there are potential side effects that can happen over a long time. Long-term treatment with sodium valproate can cause osteoporosis and osteopenia (increasing your risk of breaking a bone).

Your doctor can arrange for tests to check the strength of your bones. Regular exercise and a good diet can also help to keep your bones strong.

Can I get epilepsy medicines for free?

If you have epilepsy, you're entitled to free prescriptions for all of your medicines (not just your epilepsy ones).

To claim your free prescriptions you'll need a medical exemption certificate.

The application form for the medical exemption certificate is called FP92A. You can get this from your doctor's surgery. You will need to fill in the form, then your doctor will sign it and send it off.

Are there similar medicines to sodium valproate?

Valproic acid and semisodium valproate are very similar to sodium valproate. They work in the same way but these medicines are sometimes given at different doses for different conditions.

If you decide to try valproic acid or semisodium valproate instead, your doctor will explain how to come off sodium valproate safely.

How does it compare with other medicines for epilepsy?

There are many different medicines for treating epilepsy. It's not possible to say that one works better than the others. It varies from person to person and depends on the type of seizures and how often you have them.

Before prescribing a medicine, your doctor will also take into account your age and sex, the medicines you're already taking and any other health problems you have.

It's usual to try to treat epilepsy using a single medicine. If this medicine is not working well, or you're getting side effects, your doctor will try you on a different one.

If a single medicine is not preventing your seizures, then your doctor may recommend taking 2 or more anti-epileptic medicines at the same time.

Sodium valproate works for several different types of epilepsy. If it's giving you side effects, or you're worried it is not suitable for you, ask your doctor or specialist to recommend a different medicine.

Other anti-epileptic medicines include:

How does it compare with other medicines for migraine?

For many people topiramate, propranolol and amitriptyline work better than sodium valproate at preventing migraines. These medicines are likely to cause fewer side effects, so your doctor or specialist will usually prescribe one of these first.

Sodium valproate is not used as often for preventing migraine. However, your doctor may recommend it if these other medicines are causing side effects or are not working for you.

Your doctor may also prescribe sodium valproate if you have a health problem that means you cannot take other migraine medicines.

How does sodium valproate compare with other medicines for treating bipolar disorder?

If you have bipolar disorder, there are several types of medicine to prevent mood swings and treat mania. It's not possible to say that one works better than another and it varies from person to person.

Lithium is commonly used for bipolar disorder, as well as anti-epileptic medicines like sodium valproate and antipsychotic medicines like olanzapine. You can take sodium valproate instead of lithium, or together with lithium, depending on what your doctor recommends.

Your doctor or specialist will find the medicines that work best for you. It depends on your mood swings, how often they happen, how severe they are and how well you cope with a medicine.

Do I need to stick to the same brand of sodium valproate?

Once you're on a dose of sodium valproate that suits you, you're likely to keep taking the same type or brand. This is because it can be a problem to swap from modified release to gastro-resistant tablets.

Some people may change brands to try a different type of sodium valproate. For example they may want to try the granules instead of the tablets. If you need to change brand your doctor or pharmacist will explain how to do so safely.

However, if your epilepsy has been difficult to control in the past and the brand you're taking is working well for you, your doctor may recommend staying on the same one.

What will happen when I come off it?

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

You're unlikely to get any extra symptoms when you stop taking this medicine. However, if you're taking sodium valproate for epilepsy, it's possible that you'll get seizures again once you stop taking it. You can prevent these withdrawal seizures by reducing your dose of sodium valproate gradually.

If you're taking it for bipolar disorder or to prevent migraine, your condition could get worse for a short time after you stop taking the medicine.

Will recreational drugs affect it?

Sodium valproate can affect recreational drugs like cannabis and heroin.

If you use recreational drugs alongside sodium valproate, you may be more likely to have side effects like panic attacks, anxiety and memory loss.

Can I drink alcohol with it?

Drinking alcohol while taking sodium valproate may make you feel sleepy or tired. It's best to stop drinking alcohol during the first few days, until you see how the medicine affects you.

Will it affect my fertility?

Sodium valproate can reduce fertility in both men and women.

In men, sodium valproate has been reported to cause infertility. This may get better if you stop taking it. Do not stop or change your medicine without speaking to your doctor, as it may make your condition worse.

In women sodium valproate can change your menstrual cycle, causing delayed or missed periods. Sodium valproate has also been reported to cause polycystic ovary syndrome (PCOS), though this happens rarely.

Talk to your doctor if you're concerned about how sodium valproate may affect your fertility and pregnancy plans.

Will it affect my contraception?

Sodium valproate does not affect any type of contraception, including the combined pill and emergency contraception.

If there's a chance you could become pregnant while taking sodium valproate you must use contraception. Your doctor will put you on Prevent, the valproate pregnancy prevention programme.

Speak to a pharmacist or your doctor if you have any questions about this programme.

If sodium valproate is not working for you and you're being sick, your contraceptive pills may not protect you from pregnancy. Check the pill packet to find out what to do.

Find out more:

Can I drive or ride a bike?

You may feel sleepy, tired or dizzy when you first start taking sodium valproate. This may also happen if your dose has increased. If you're affected, do not drive or ride a bike until you feel more alert.

If you have epilepsy, you're not allowed to drive until you've had no seizures for 1 year (or only have seizures while you're asleep).

If you change your epilepsy medicine, your doctor will tell you whether you need to stop driving and for how long.

Driving rules if you change or withdraw your medicine, Epilepsy Action

Epilepsy and driving information, GOV.UK

Sodium valproate - Brand names: Dyzantil, Epilim, Episenta, Epival

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