What are generic and branded drugs?
Understanding the differences between generic and branded anti-epileptic drugs (AEDs) could make a difference to the effectiveness of your treatment. Switching from a braanded drug to a generic drug, or switching between generic drugs could cause side effects or a breakthrough seizure.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 not like a short course of treatment (such as antibiotics) and are often taken for many years.
When a drug is prescribed by brand name (that is, the brand name appears on the prescription) a pharmacist has to give that specific version. However, if a drug is prescribed generically (that is, the prescription only has the generic name of the drug) a pharmacist can give any version of a drug that has this generic name. Although not all drugs have generic versions available (those that are on patent- see below), for some there are several different generic versions on the market. This can result in someone being giving a different version of their AED with each prescription they get.
Every drug has a generic name. This refers to the active ingredient in the drug (the part of the drug which works for the reason you take it). For example, carbamazepine or sodium valproate.
Branded drugs are the original version of a drug produced by a pharmaceutical company. These drugs (sometimes called the ‘innovator product’) have a brand name as well as a generic name. For example, Tegretol is the brand name of the AED carbamazepine.
To start with, only the company that developed the drug can produce it. This is called being ‘on patent’. After a time other companies are allowed to start producing their own version of the drug (when it becomes ‘off patent’). These other companies might call that drug by just the generic name (for example, carbamazepine) or they might give it another name that applies just to their version (sometimes called a ‘branded generic’) such as Carbogen. Once this happens, there can be several versions of a generic drug available.
Different versions of a drug with the same generic name will all have the same active ingredient. However, drugs also have other ingredients (such as colouring, and binding ingredients – which hold the tablet together) and these can vary from one version of the drug to another. This means that one version is not exactly the same as another. These other ingredients can sometimes affect how the drug is absorbed into the body, which could affect how it works in the brain to control seizures. Switching between one version of a drug and another might affect the amount of active ingredient reaching the brain. If the amount is lowered, this could cause seizures. If the level is higher, it could cause side effects.
How similar are generic drugs?
When a new generic version of a drug is developed, it has to be shown to be ‘bioequivalent’ – within a certain range – to the innovator product. This means that 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, they do not have to be compared to any other generic versions. This means that two generic versions might be quite different from each other.
Different versions of drugs also often differ in size, shape, colour and the writing on them. This can be quite confusing if someone is used to have a particular size or shape.
MHRA (Medicines and Healthcare Regulatory Authority
The MHRA has issued new guidance guidance on prescribing anti-epileptic drugs . This aims to help prescribing doctors decide whether or not it is important to maintain a consistent supply of particular AEDs for individuals with epilepsy.
Consistency of supply means getting the same version of a drug with every prescription. It doesn’t matter if someone is on a branded or a generic drug (one is not ‘better’ than the other) but finding a version that works and keeping to the same version is important.MHRA guidance.
What are the concerns about switching between drugs?
For many people with epilepsy, medication is vital to their seizure control. The key to medication working well is having consistent levels in the body throughout the day and night. This is why medication works best when it is taken at around the same time or times each day. There are several reasons why switching between different version of AEDs could be a problem for some people.
- Switching between different versions could affect the levels of AED in the blood, which could cause seizures or side effects (see 'What are generic and branded drugs, and why is this important?' above)
- Individuals with a learning disability or who rely on others to manage their medication may not be aware of the potential impact of switching AEDs, or may not be aware of when their AEDs have been switched
- Individuals with memory problems or confusion may not remember what their AEDs look like and so find it hard to ensure that they are receiving the same medication as usual. Or they may be confused about what medication they are taking, particularly if it keeps changing in colour or size. This could lead to making errors in what they are taking
- For some individuals anxiety can be a trigger for seizures, and getting different versions of AEDs could increase this anxiety (particularly if the individual is concerned that a change in version could trigger a seizure).
Whatever the reason, switching between different versions of a drug can be a real cause for concern, and have a huge impact on, individuals with epilepsy.
What can I do if I am worried about my drugs being changed?
There are several things you could do to try and ensure you get the same version of your AEDs with every prescription.
Talk to your neurologist
It will usually be a neurologist who makes decisions with you about which medication to take, and they will usually inform your GP of this. You can talk to them if you are concerned about switching between different versions of a drug. Ask if they can pass this information on to your GP, along with instructions on how to prescribe the same version each time.
Talk to your GP
Your GP will usually be responsible for your repeat prescriptions. You can talk to your GP about any concerns you have, and ask them to prescribe by brand name (if you are taking a brand version) or to include the name of the manufacturer, alongside the generic name, on the prescription.
Talk to your pharmacist
Many pharmacists will keep patient records with details about what medication someone takes. If you use the same pharmacy for each prescription, they might be able to make sure they get the same versions of your AEDs for you each time. If pharmacists don’t have your usual version in stock, you can ask for your prescription back so that you can take it to another pharmacy. For this reason, it is always a good idea to check that you have your correct AEDs while you are at the counter, as a pharmacist won’t be able to change it once you have left the counter.
Get to know your medication!
It can be a good idea to make a list of your AEDs: the generic name, any brand name, and the name of the manufacturer. You could also include the colour and shape, to help you recognise it. This might help when you check your prescription from the doctor, or when collecting a prescription from the pharmacy. You could also use your phone to take pictures of your medication, or use our Epilepsy Society Smartphone app, which has a section on recording what medication you take.
It is important to remember that by always taking the same version of a drug there may be less risk of having a seizure. See Getting the right medication which includes a letter to give to your healthcare professional to explain why this is important and taking your AEDs for tips on effective medication.
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