Exelon (rivastigmine): drug treatment for Alzheimer's disease

Introduction

Exelon is the brand name for the drug rivastigmine. It is licensed for the treatment of mild to moderately severe Alzheimer's disease, and was launched in 1998.

Exelon is one of a group of three drugs for people with Alzheimer's disease called cholinesterase inhibitors. The other two are called Reminyl and Aricept.

Exelon is not claimed to be a cure for Alzheimer's disease. It treats the symptoms only and there is no evidence that it could halt or reverse the process of cell damage that causes Alzheimer's disease.

This information sheet is for people with Alzheimer's disease, their families and carers, and for anyone else interested in the treatment of Alzheimer's disease. It updates an earlier version published in May 1998.

How does Exelon work?

Acetylcholine is a neurotransmitter, a brain chemical which carries messages between brain cells. When someone has Alzheimer's disease, it seems that - among other changes - his or her brain produces less acetylcholine. Normally there is a repeated cycle in the brain in which acetylcholine is made, transmits messages and is then broken down by a special enzyme (acetylcholinesterase).

Exelon aims to prevent the last part of this cycle so that the acetylcholine is not broken down. There is then more acetylcholine available in the brain to carry messages between the brain cells.

Who might benefit?

Exelon is intended only for people with Alzheimer's disease, and not for people with other kinds of dementia. It is licensed only for people who are in the mild to moderately severe stages of the illness.

There is some evidence that Exelon may be helpful to people with a specific type of dementia, called Lewy Body dementia.

It is important to realise that unfortunately Exelon will not help everyone who tries it.

What effect might it have?

The effect of the drug will vary for different people. Some will not notice an effect at all. Others may find that their condition improves, or that they stay the same when they would have been expected to get gradually less able because of the progression of Alzheimer's disease.

SIGN guideline

The Scottish Intercollegiate Guidelines Network (SIGN) is an organisation which produces guidelines and recommendations on how to treat medical conditions. These recommendations are then used by health professionals, such as doctors.

SIGN reviewed studies which investigated the effects of Exelon. It found that Exelon improved cognition (mental functions or processes, such as memory) and function (i.e. the person’s ability to carry out normal activities).

One study found that the effects of Exelon on cognition were more robust in people with moderately severe Alzheimer's disease.

Another study found that people with Alzheimer's disease and high blood pressure gained more benefit to their cognition than people without high blood pressure.

Exelon was also found in two studies to be effective in managing associated symptoms of Alzheimer's disease.

One study found that Exelon was effective in treating cognitive decline, anxiety, hallucinations and apathy in people with Lewy body dementia. Another study found that when people with Lewy body dementia stopped taking Exelon, their cognitive function declined quickly within three weeks.

SIGN recommendation

SIGN recommends that Exelon can be used to treat cognitive decline and associated symptoms in people with Alzheimer's disease and people with Lewy Body dementia at a dose of 6 milligrams (mg) per day and above.

How is Exelon taken?

Exelon is taken twice a day with food. It is recommended that people start with a low dose of 1.5 mg twice a day and build up to a total of 6–12 mg a day. It comes in 1.5 mg, 3 mg, 4.5 mg and 6 mg tablets. It also comes in a liquid form for people who have difficulty swallowing pills.

If a dose is missed it should be taken as soon as the person remembers. However, if it is near to the time of the dose, the person should wait and take the next dose at the normal time. Two doses should not be taken at once.

A patch (like a sticking plaster) which releases Exelon has been developed by the pharmaceutical company who make Exelon. It has recently been given approval to be used in the United States and recommended for approval in Europe but is not yet commercially available in the UK.

Are there any side effects?

The most likely side effects are nausea, vomiting, loss of appetite and weight loss, so the drug should be taken with a meal. If these or any other symptoms occur, tell the doctor at once. Side effects are more common when someone begins to take Exelon or when the dose is increased, but often settle down with time.

It is not possible to tell who will have side effects and who will not.

Interactions with other drugs

It is important to tell the doctor about all the drugs that the person with Alzheimer's disease takes because Exelon may interact with them. This includes prescription and non-prescription drugs, vitamins, herbal remedies or dietary supplements.

Interactions with other conditions

Exelon works by increasing or maintaining levels of acetylcholine in the brain. Other drugs also increase the activity of acetylcholine and should not be taken in combination with Exelon as this may lead to increased side effects.

Some other conditions, such as stomach ulcers, lung diseases, asthma, Parkinson’s disease, urinary incontinence or some heart diseases might possibly be affected by taking Exelon. People with some of these conditions may be prescribed anticholinergic medicines. These work by decreasing levels of acetylcholine. If taken in combination with Exelon this could lead to both medicines being less effective with each drug cancelling out the effects of the other.

The doctor of the person with Alzheimer's disease should be informed of any other illnesses the person has. In theory, some illnesses, such as stomach ulcers or lung diseases such as asthma, might possibly be affected by taking Exelon. The doctor must also be informed if the person is pregnant, trying to get pregnant or breastfeeding.

Overdose

If too much Exelon has been taken, contact a doctor or hospital straight away for advice. Take any remaining tablets and the packaging with you. NHS 24 (telephone 08454 24 24 24) may be able to give you advice when your GP practice or health centre is closed.

Stopping the drug

It is best to discuss with the doctor when to stop the drug. However, it is possible to stop immediately if the person with Alzheimer's disease or his or her carer feels this is necessary. If this is the case, the doctor should be consulted as soon as possible.

How to get Exelon

NHS prescriptions

Before 2006, people with mild and moderate Alzheimer's disease could get Exelon on NHS prescription if a doctor believed the drug could help. However, in 2006 NHS Quality Improvement Scotland (NHS QIS) decided that Exelon should only be available on NHS prescription to people with moderate Alzheimer's disease.

Moderate Alzheimer's disease is defined as a score between 10 and 20 points on a test called the Mini Mental State Examination (MMSE). MMSE is a commonly used test for people with memory problems or when a diagnosis of dementia is being considered.

The NHS QIS decision means, in theory, that people with mild Alzheimer's disease will not be eligible for Exelon until their condition gets worse and they are assessed as being in the moderate stage. In practice, the doctor will use his or her clinical judgement to determine whether or not to prescribe the drug for an individual.

The NHS QIS decision should not affect people with mild Alzheimer's disease who began taking Exelon before 2006. They can continue to take Exelon until they, their carer and/or their doctor think they should stop taking it.

Exelon can be prescribed by a specialist doctor (for example, a psychiatrist) or sometimes by a GP. If the person with Alzheimer's disease needs to see a specialist, his or her GP will arrange this. The doctor prescribing Exelon should seek the carer’s views of the condition of the person with Alzheimer's disease as part of this process.

People taking Exelon will be reviewed every six months. The review will be done by a GP or specialist team. The review will include a number of tests, including the MMSE. Again, the carer’s views should be taken into account.

If the MMSE score stays above 10 and the results of other tests show that Exelon is having a worthwhile effect, then the person with Alzheimer's disease can continue taking Exelon. If the MMSE score is below 10, then the person may have to stop taking the drug.

Regardless of whether the person with Alzheimer's disease is suitable for drug treatment, the doctor can give information on local services that may help people to cope with the illness. People with Alzheimer's disease and their carers can also call the 24 hour Dementia Helpline free on 0808 808 3000 for information or to talk things over.

Private prescriptions

People with mild Alzheimer's disease may be able to get Exelon on a private prescription if they are unable to get it by NHS prescription. Any doctor can, in theory, write a private prescription if he or she thinks the treatment would help the person and if the doctor is willing to accept responsibility for the decision to prescribe the drug.

A private prescription can be obtained through a consultant or other specialist, a private hospital, or GP. However, hospital doctors may not be allowed by their health boards to write private prescriptions for patients after assessing them at a NHS consultation. This could mean that the person with Alzheimer's disease has to pay for a private consultation.

GPs are not allowed to charge for writing a private prescription if the patient is registered for NHS care with that GP or another GP in the same practice. However, not all GPs are willing to issue private prescriptions, and some may feel they do not have the right expertise to prescribe Exelon, as it is normally only prescribed by hospital specialists.

Private specialists will write private prescriptions if they consider the drugs would be beneficial. However, it is unlikely that they would do so without arranging to monitor the person with Alzheimer's disease for the effects of the drug. If the person with Alzheimer's disease is going to see a specialist privately, ask for a written estimate of any additional on-going costs associated with the prescription.

There are advantages to staying within the NHS system for dementia care, other than reduced cost and ongoing monitoring of your condition, such as getting access to other NHS services like community nursing, continence services and various therapies.

Take the prescription to the pharmacist or chemist, as you would with a NHS prescription.

Cost

NHS prescriptions

If the person with Alzheimer's disease is prescribed Exelon on the NHS, he or she will have to pay the normal prescription charge unless he or she is eligible for free prescriptions – ask a pharmacist for more details.

Private prescriptions

Private prescriptions are not covered by the NHS prescription charge and are not supplied free to people who do not pay prescription charges. A dispensing fee on top of the full cost of the drug will also be charged. This could be in the region of £50. It may pay to shop around if you can, as dispensing charges can vary from pharmacy to pharmacy and even between branches of the same company.

The cost of a 6 mg per day dose of Exelon tablets for one year would be £443.46 (based on the 6 mg tablet in a box of either 28 or 56). The cost of a 12 mg per day dose of Exelon for one year would be £886.95 (based on taking the 6 mg tablet twice a day in a box of either 28 or 56).

The cost of the liquid for daily doses of 6 mg for one year would be £1064.34. The cost of the liquid for daily doses of 12 mg for one year would be £2128.68.

For more information on private prescriptions, see Information sheet 37 at
www.alzscot.org/pages/info/privateprescription.htm

If you or the person you care for have been refused an NHS prescription for Exelon or any of the dementia drugs, Alzheimer Scotland would like to know. Write to the Policy Director, Alzheimer Scotland, 22 Drumsheugh Gardens EH3 7RN or email alzheimer@alzscot.org