Consistency of supply

Epilepsy Action against the automatic substitution of anti-epileptic drugs

• Automatic substitution campaign

Epilepsy is defined as a tendency to have recurrent seizures. Approximately 456,000 people in the UK have a diagnosis of epilepsy, and take anti-epileptic drugs.

Seizure control is the primary goal in managing epilepsy, as a single seizure can result in the automatic loss of a person’s driving licence, risk of injury and reduced quality of life. Uncontrolled epilepsy can also increase the risk of premature death.

What is the issue?

The 2009 Pharmaceutical Price Regulation Scheme (PPRS) includes proposals to expect the pharmacist to automatically substitute a generic version of a prescribed drug where a branded drug is named on the prescription.

Epilepsy Action strongly recommends that all anti-epileptic drugs (AEDs) are specifically excluded from the scheme.

There is strong evidence that brand switching 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.

The current guidelines

The National Institute for Health and Clinical Excellence (NICE) epilepsies guideline(1) states that changing the formulation or brand of anti-epileptic drugs (AEDs) is not recommended. In addition, the NHS Choices website (2) also states that AEDs should be prescribed by brand to ensure patients receive the same version and preparation each time. There are numerous academic research papers which urge caution and recommend further research into the effects of substituting AEDs.

Cost savings

• Annual cost of AEDs for epilepsy in England is 1.25 per cent of the NHS drugs bill. (3)  
• Anticipated annual savings on the NHS drugs bill by the PPRS generic substitution proposals is estimated at £50m at current prices.
• The AED ‘share’ of the PPRS proposed savings is £625,000.

While substitution of named brand AEDs by generics may have an immediate cost saving to the NHS, the government has not undertaken a cost-benefit analysis, nor has it estimated the possible numbers of patients that could be affected (4). Assuming this target is met, any saving from the PPRS proposal would be outweighed by the additional cost of just 35,000 additional GP appointments; or 6,250 additional consultant appointments: or 10,000 additional A & E attendances (or any combination of these).

Epilepsy Action survey

A 2009 Epilepsy Action survey has revealed that these proposals could 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, with most experiencing an increase in seizures.

Almost half (43 per cent) of those who spoke to their pharmacist were told that there was nothing to worry about and that all brands were the same. One in seven (15 per cent) found that pharmacists were not aware of the issue.

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 brand. There have not been adequate clinical trials to draw conclusive findings, 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. (5) 

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 (6).  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, (7) and this could affect absorption levels.

Also we cannot rule out that stress over irregular prescriptions may worsen some peoples’ epilepsy. With such high-risks associated with a change in someone’s epilepsy, the unknown consequences of changing brands could have a psychosomatic affect, leading itself to a loss of control.

For some people, the confusion of receiving different versions of medication may affect if and when they take their medication, with many AEDs being of different size, shape and colour to one another.

What does Epilepsy Action want?

Epilepsy Action is campaigning for an exemption from this scheme for anti-epileptic drugs. We understand the proposals include an opt out of PPRS substitution via a tick box on the prescription form. We do not feel this would be a satisfactory solution as the Epilepsy Action survey showed a lack of understanding of the issues surrounding brand switching of AEDs among many GPs.

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.

We would like to emphasise, Epilepsy Action is not against generic brands being prescribed to individuals with epilepsy. We believe the key is that they receive a consistent supply of the same brand of AED at every prescription and dispensing.

People with epilepsy should receive the same version of anti-epileptic drug whenever they get a repeat prescription unless their clinician prescribes otherwise.

For further information on how you can help Epilepsy Action’s campaign against the automatic substitution of anti-epileptic drugs, please contact Pete Scott, Campaigns and Policy Officer, at pscott@epilepsy.org.uk or 0113 250 8877.

If you are concerned about how this will affect you and your medication, you can ring our epilepsy freephone Helpline on 0808 800 5050. Epilepsy Action advises that you do not stop taking your medication without speaking to your doctor first.

References

• http://www.nice.org.uk/nicemedia/pdf/word/CG020niceguidline.doc
• http://www.nhs.uk/chq/Pages/1003.aspx?CategoryID=73&SubCategoryID=108
• Private correspondence, John Duncan MA DM FRCP FMedSci, Medical Director, National Society for Epilepsy, 13/8/9
• Mr Mike O’Brien QC MP, Health Minister, House of Commons written answer, 13 July 2009
• Crawford P, Hall W, Chappell B et al (1996). ‘Generic Prescribing for Epilepsy. Is it Safe?’ Seizure; 5:1-5
• Besag F M C. (2000) ‘Is Generic Prescribing Acceptable in Epilepsy?’ Drug Safety no.3, pp173-182
• Richens A (1997). ‘Impact of Generic Substitution of Anticonvulsants on the Treatment of Epilepsy’. CNS Drugs; 8 (2): 124-133. Also: Guberman A and Corman C (2000). ‘Generic