Common questions about sodium valproate - Brand names: Dyzantil, Epilim, Episenta, Epival

Sodium valproate is an anticonvulsant (or anti-epileptic) medicine. It prevents epileptic seizures by reducing the 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.

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

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

However, there are possible 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 healthy diet can also help to keep your bones strong.

Sodium valproate is not known to be addictive.

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 some people may be sensitive to the very slight differences between different brands of sodium valproate. It can also be a problem for some people to swap types of sodium valproate, for example, from slow-release to gastro-resistant tablets.

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.

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 type or brand, your doctor or pharmacist will explain how to do this safely.

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.

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 stop taking sodium valproate safely.

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:

• carbamazepine
• clobazam
• ethosuximide
• gabapentin
• lamotrigine
• levetiracetam
• phenytoin
• pregabalin
• topiramate

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.

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.

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 GP surgery. You will need to fill in the form, then your doctor will sign it and send it off.

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

However, if sodium valproate makes you vomit or have severe diarrhoea for more than 24 hours, your contraceptive pills may not protect you from pregnancy. Look on the pill packet to find out what to do.

Find out more:

• What to do if you're sick or have diarrhoea when taking the combined pill
• What to do if you're sick or have diarrhoea when taking the progestogen-only pill

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

Find out more about Prevent on the Electronic Medicines Compendium website (PDF only, 318KB)

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

You may feel sleepy, tired or dizzy when you first start taking sodium valproate. This may also happen if your dose has increased. If this happens to you, do not drive, cycle or use machinery or tools 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.

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.

Apart from being careful with alcohol, you can eat and drink normally while taking sodium valproate.

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.

Talk to your doctor if you think you might use recreational drugs while taking sodium valproate.

You can find out more about the side effects of recreational drugs on the Frank website.