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of everyone affected by epilepsy


Consistency of supply

Epilepsy Action strongly believes people with epilepsy should receive the same version of anti-epileptic drug (AED) whenever they get a repeat prescription unless their clinician prescribes otherwise. It should be from the same manufacturer, and from the same country. This applies to generic versions, ‘branded’ generics and for brand leaders.

What is the issue?

When a new drug is created by a drug company, only they are allowed to make it for the first ten years. After ten years, other companies are allowed to produce the drug, meaning there can be different versions of a drug to choose from.

There is evidence that switching version for many people with epilepsy has caused breakthrough seizures, worsening of their seizure control or worsening of side-effects. These are major issues for many people with epilepsy, and can affect employment, education, and social life. For example a single seizure can cause the loss of a driving licence for a year, and this may impact on a person’s quality of life.

Why may substitution affect people with epilepsy?

There is no conclusive scientific explanation for why some people with epilepsy are affected by a change in their AED version. There have not been adequate clinical trials, partly because of the ethical issues of putting people at risk of losing seizure control.

The statement that all versions of a drug are identical is often made. However in medication the word ‘identical’ means ‘so similar that it makes little difference’. In the drug treatment of epilepsy however, subtle differences may have profound effects . [1]

One explanation is that tiny differences in the way in which ingredients are handled by manufacturers can affect how they are absorbed by the body [2] .  We know that even very small differences in particle size can affect the rate of absorption. Inactive ingredients including binding materials and colourings may differ [3],  and this could affect absorption levels.

Also we cannot rule out that stress over inconsistent dispensing of AEDs may worsen some peoples’ epilepsy. With such high risks associated with a change in someone’s epilepsy, the unknown consequences of changing versions could have a psychosomatic affect. This can lead to a loss of seizure control.

Many AEDs are a different size, shape and colour to one another. For some people, the confusion of receiving different versions of medication may affect if and when they take their medication. It can also be difficult to tell the difference between generic versions because many generics look very plain and can look alike. This may mean that some people are not aware when they have been given a different version.

Parallel imports

Many of the issues of drug switching also apply to parallel importing. This is when a drug is made in other factories, or abroad, and is available alongside the original version. Drugs made by the same company but in a different factory or country are not always the same. They may use different recipes which mean they can be different versions. This is why we want people to get the same drug from the same place of origin each time.

For more information about these issues, please visit our advice and information page 'Getting the same version of your anti-epileptic drug each time'

Epilepsy Action survey

A 2009 Epilepsy Action survey revealed that substituting AEDs could negatively affect as many as 50,000 people with epilepsy in the UK.

The survey showed that of those given alternative versions of their usual anti-epileptic drugs (AEDs) in the last year, almost a quarter (23 per cent) said their epilepsy got worse. Most of these people reported an increase in the number of seizures they had. Almost half (43 per cent) of those who spoke to their pharmacist were told that there was nothing to worry about and that all versions were the same. One in seven (15 per cent) found that pharmacists were not aware of the issue.

In its survey, Epilepsy Action asked people whether they spoke to their doctor after having been given a different version of their AED. Almost a third (31 per cent) were told there was nothing to worry about. Nearly a quarter (22 per cent) were told all brands were the same and one in six (16 per cent) found their doctor was not aware of the issue.

What does Epilepsy Action want?

Epilepsy Action wants people with epilepsy to receive the same version of their drug each and every time they pick up their prescription. We believe that a person should receive a different drug if their clinician has asked for them to receive a different version for clinical reasons. Clinical reasons could include: problematic side-effects of a drug, and changes to treatment to improve seizure control.

We are constantly working to make sure that people are aware that switching can cause problems for some people with epilepsy. We will continue to do this, so more people receive the AED that is best for them, each and every time they visit a pharmacy.

We would like to emphasise that Epilepsy Action is not against alternative versions being prescribed to individuals with epilepsy. Many people are successfully treated using generic versions and we know some people prefer a generic version to a branded alternative. We believe the key is that they receive a consistent supply of the same brand of AED at every prescription and dispensing.

The 2009 campaign

In 2009, the Department of Health in England announced proposals that would allow pharmacists to give out a different version of a drug, if a cheaper version is available. Epilepsy Action campaigned to stop this from being introduced for AEDs.

Over 12,000 people signed a Number 10 petition calling for AEDs to be exempt from the proposals. The Department of Health consulted on these proposals and in its response said epilepsy drug safety concerns were one of the main issues raised in consultation responses.

In October 2010, it was announced that the government would not be introducing this proposal, and would be looking at other ways to reduce the NHS drug bill.
For more information on this campaign, please click here.

The Departments of Health in Scotland, Northern Ireland and Wales do not have any plans to introduce generic substitution.

What other groups say

The National Institute for Health and Clinical Excellence (NICE) epilepsies guideline states that changing the formulation or brand of anti-epileptic drugs (AEDs) is not recommended.

The Scottish Intercollegiate Guidelines Network (SIGN), in their guidance for epilepsy, state: ‘Formulations of AEDs are not interchangeable and generic substitution should not be employed.’ [4]

This is advice taken from the Royal Pharmaceutical Society of Great Britain practice guidance on epilepsy

“It is important that, wherever possible, patients with epilepsy always receive the same brand of AED because switching versions could potentially affect seizure control. For a patient who has been seizure-free, having a breakthrough seizure could have a devastating effect, for example, in terms of driving and employment.”

Epilepsy Action advice

You can download a copy of our ‘Getting the same version of your anti-epileptic drugs every time’ factsheet here. This covers many of the points on this page.

Legally, a pharmacist has to give out the drug that is written on prescription. This is written in Section 58 (2) (a) of the Medicines Act 1968. However if the generic name of a drug is written on a prescription, the pharmacist can dispense any brand, generic or imported version of that medicine.

Some people may have concerns that they could receive different versions of their AED at different visits to the pharmacy. If this is the case, we recommend that you speak to your prescriber about stating the name of your version on your prescription. This could include the location where your version is made. Your pharmacist doesn’t have to take any notice of this, however many pharmacists do their best to help their customers. Therefore we think it is still worth asking your prescriber to state your version on your prescription if you are concerned.

The Yellow Card Scheme

The UK Medical Health Regulatory Agency (MHRA) operates the Yellow Card Scheme, to highlight safety issues or side-effects with medications.

Yellow Card reports made by patients and health professionals are investigated by the MHRA’s team of medicine safety experts. This is doctors, pharmacists and scientists who study the benefits and risks of medicines.

If you have a problem with a medication, you may consider logging a report through the Yellow Card Scheme.

Don’t Sub Our Drugs card

We know that many doctors and pharmacists are not aware of the problems that can be caused by switching versions of AEDs. This is an issue which only affects a few types of drugs, and epilepsy drugs are one of these.

We try to inform pharmacists that this is a big issue for AEDs. However we are not able to speak to all pharmacists in the UK. To help people inform their pharmacist, and make your pharmacist aware of the issue, we have produced a small card to carry in your purse or wallet.

If you are concerned about how this will affect you and your medication, you can ring our Epilepsy  Helpline on freephone 0808 800 5050 (UK) or email helpline@epilepsy.org.uk

Epilepsy Action advises that you do not stop taking your medication without speaking to your doctor first.


  • [1]  Crawford P, Hall W, Chappell B et al (1996). ‘Generic Prescribing for Epilepsy. Is it Safe?’ Seizure; 5:1-5
  • [2]  Besag F M C. (2000) ‘Is Generic Prescribing Acceptable in Epilepsy?’ Drug Safety no.3, pp173-182
  • [3] Richens A (1997). ‘Impact of Generic Substitution of Anticonvulsants on the Treatment of Epilepsy’. CNS Drugs; 8 (2): 124-133. Also: Guberman A, Corman C. Generic substitution for brand name antiepileptic drugs: a survey. Can J Neurol Sci  2000; 27:37–43.
  • [4] Ref: ‘Diagnosis and Management of Epilepsy in Adults: a National Clinical Guideline (70)’. Scottish Intercollegiate Guidelines Network. Section 3.2, page 9. April 2003.

Comments: read the 1 comments or add yours


The fact that Lamotrigine Teva is being discontinued has already had a big effect on my partner. He has been obliged to take 8 x 25mg tablets of Teva instead of 2 x 100mg, for the past 2 months. In that time he has had 2 tonic clonic seizures, whereas before that he had 2 in 3 years...Then in January when Teva disappears completely, he will need to switch to another brand of Lamotrigine. He is obviously sensitive to small differences and very worried...What are other people on Teva switching to?

Submitted by Kim on

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