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generic and branded anti-epileptic drugs

Getting the same version of anti-epileptic drugs (AEDs) with each prescription may contribute to how well the drug works for that person. Switching to a different version of a drug could cause confusion, anxiety, side effects or a breakthrough seizure in some people.

Anti-epileptic drugs (AEDs) aim to prevent seizures from happening. To be most effective, they need to be taken every day, at around the same time. They are often taken for many years, unlike a short course of treatment (such as antibiotics).

What are branded drugs?

'Branded' drugs are the original version of a drug produced by the drug (pharmaceutical) company which developed the drug. To start with, only the company that developed the drug can produce it. This is called being ‘on patent’, and the drug will have a brand name that only that company can use. For example, Tegretol is the brand name of the AED carbamazepine.

What are generic drugs?

All drugs have an ‘active ingredient’ (the part of the drug that treats the condition for which you take it). This ingredient is often referred to as the ‘generic’ name.

Once a branded drug has been on the market for a number of years, other companies are allowed to start producing their own version of the drug (after it becomes ‘off patent’). These other companies might call their version of the drug by just the generic name, such as ‘carbamazepine’, or they might give their version another name (sometimes called a ‘branded generic’), such as ‘Carbagen’.

Several drug companies might produce their own versions of a generic drug, but they will all contain the same active ingredient.

Different versions of AEDs will look different

Each company’s version of a drug will usually look different, so that you can tell different versions apart, and you can recognise a particular drug from a specific drug company. The differences include the size, colour and any writing on the tablets or capsules themselves. The packaging will also look different.

If two different AEDs have the same generic name, are they exactly the same?

Although AEDs with the same generic name have the same active ingredient, this does not mean that they are exactly the same. This is because drugs contain other ingredients, such as colouring and binding agents (ingredients that hold the tablet together), which can be different from one version to another. In some cases, these other ingredients might affect how the drug is absorbed in the body, which could affect how well the active ingredient works in the brain to stop seizures.

How different are generic drugs with the same name?

When a new generic version of a drug is developed, it has to be shown to be ‘bioequivalent’ (have a similar effect) – within a certain range – to the original ‘on patent’ brand. This means they have to be ‘similar enough’ to the original in how they work in the body and the amount of active ingredient that gets to the brain. However, a generic version only has to compare in this way to the brand version, not to other generic versions. So, two generic versions might have greater differences between them in the way they work, than the differences between a generic and a brand version.

Which is better, branded or generic?

A ‘brand’ version of an AED is not ‘better’ or ‘worse’ than a generic version of that drug. The important thing is that you and your doctors find a version of a drug which suits you, and you take this version consistently. ‘Consistency of supply’ means getting the same version of a drug with every prescription.

MHRA guidance on prescribing anti-epileptic drugs

The Medicines and Healthcare products Regulatory Agency (MHRA) has issued guidance on prescribing anti-epileptic drugs. They say that certain AEDs must be prescribed with the same version, and that for other AEDs this is less important. This aims to help prescribing doctors decide whether they should prescribe a particular version.

Concerns about switching between drugs

There are several reasons why switching between different version of AEDs may be a problem for some people.

  • Switching from one version of a drug to another might mean that higher, or lower, amounts of active ingredient reach the brain. If the level is lower in one version than another, seizures could happen. If the level is higher, this could cause side effects.
  • People with memory problems or confusion may not remember what their AEDs look like, and so may find it hard to check that they are getting the same medication each time. Or they may get confused about what medication they are taking, especially if it has changed in colour or size. This could lead to errors in prescribing or taking AEDs.
  • Being given different versions of AEDs could cause anxiety, which is a common trigger for seizures.

What can I do if I am worried about my AEDs being switched?

Talk to your neurologist

If you have a neurologist, you can talk to them about your concerns. If they agree that you need to always have the same version of AEDs, you can ask them to pass this information on to your GP, with instructions on how to prescribe the same version each time.

Talk to your GP

Your GP is usually responsible for your prescriptions. If you are taking a brand version of your AED, you can ask them to write the brand name on your prescription. If you take a generic version, ask them to write the name of the manufacturer, with the generic name.

Talk to your pharmacist

If you use the same pharmacy regularly, your pharmacist may keep a record of what medication you take. They might be able to make a note to get the same version of your AEDs for you each time. If pharmacists don’t have your usual version in stock, you can ask for your prescription back, and take it to another pharmacy. Check that you have your correct AEDs while you are at the pharmacy counter, as they won’t be able to change it after you leave the counter.

Download a letter from our medical director to give to your GP, neurologist or pharmacist, supporting your right to ask to be prescribed the same version of your AEDs each time. Or call our helpline for a copy.

Get to know your medication

It can be a good idea to keep a list of your AEDs: the generic name, any brand name, and the name of the manufacturer. You could also make a note of the colour and shape, to help you recognise it. This might help you to check your prescription from the doctor, or from the pharmacy.

You could also use your phone to take pictures of your medication, or use our free Smartphone app, which has a section on recording what medication you take.

Helping you to take your AEDs

Other things that might help you to take your AEDs, and to get the best effect from them include the following:

  • A drug wallet (pill box) can help you to keep track of when you have taken your medication.
  • A seizure diary can help to keep track of your seizures and see if there is any pattern as to when they happen. Diaries can also help your doctors to see whether your medication is working.
  • The patient information leaflet (PIL) that comes with your AEDs explains what to do if you have any problems with your AEDs, such as missing a dose or being sick.
  • If you are prescribed other medication, ask your doctor or pharmacist to check whether this medication could affect your AEDs, or vice versa.