Doses for Alzheimer's disease drugs

Learn about the recommended dose for different types of prescribed drugs, what form they are dispensed in and also what to do if a dose is missed.

Taking drugs as prescribed

The person should take the drugs as prescribed and the doctor should try to ensure this is done.

The person may benefit from using a pill box with different compartments for each day of the week, containing the prescribed dose. The pharmacist may be able to supply drugs pre-packed in this way.

Missing a dose of drugs

If the person misses a dose of any of these drugs, they should take it as soon as they remember, as long as it is on the same day.

If it is the next day, the person should not take two tablets, but should simply continue with their normal dose.

Help with everyday tasks

Find out what equipment or 'assistive technology' is available to ensure that everyday activities, such as taking medication, is more manageable.

Learn more

How much is a normal dose?

Doses vary. Usually a person with Alzheimer's disease will start on a low dose, which will be increased later to make the treatment more effective.

Some people may not be able to take the highest dose because of side effects. The doctor will prescribe the best dose for each individual.

Donepezil

  • Donepezil is available in 5mg or 10mg tablets. It is taken once a day, usually at bedtime.
  • Treatment is started at 5mg a day and then increased to 10mg a day after one month, if necessary.
  • The maximum licensed total daily dose is 10mg.

Rivastigmine

  • Rivastigmine comes in capsules or a solution to drink. It is taken twice a day, with morning and evening meals.
  • People start with 3mg a day in two divided doses, which will usually increase (at intervals of at least two weeks) to between 6mg and 12mg a day.
  • The maximum licensed total daily dose for oral rivastigmine is 12mg.

Rivastigmine patches are also available. These deliver daily doses of 4.6mg, 9.5mg or 13mg, with fewer side effects than the capsules.

Patches are suited to people who struggle with taking medication by mouth; they are popular with carers.

Only one patch should be applied at any one time and it should be put on different parts of the skin each time, to avoid the person getting a rash.

Galantamine

  • The recommended starting dose for galantamine is 8mg each day for four weeks. It is then increased to 16mg a day for another four weeks, then kept at a dose of between 16 and 24mg daily.
  • Galantamine is made in a variety of forms including a 4mg/ml (twice-daily) oral solution, and tablets of 8mg and 12mg.
  • Slow-release (XL) capsules are available in doses of 8mg, 16mg and 24mg. These are popular because they only need to be taken once a day.
  • The maximum licensed total daily dose for galantamine is 24mg.

Memantine

  • Memantine comes in two forms: as 10mg and 20mg tablets, and as 10mg oral drops.
  • The 10mg tablets can be broken in half (into 5mg doses) and taken with or without food.
  • The recommended starting dose is 5mg a day, increasing every week by 5mg, up to 20mg a day after four weeks.
  • The maximum licensed total daily dose for memantine is 20mg.

According to NICE guidelines (2011),  it states the specialist should seek the views of the carer on the condition of the person with dementia, before treatment and during follow-up appointments. They should also seek the views of the person with dementia.

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