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.
- Drug treatments for Alzheimer's disease
- How do drugs for Alzheimer's disease work?
- Effects of Alzheimer's disease drugs
- Prescribing Alzheimer's disease drugs
- Are Alzheimer's disease drugs effective for other types of dementia?
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- Starting and stopping treatment
- Research into new treatments
- Drug treatments for Alzheimer's disease - other resources
Drug treatments for Alzheimer's disease
Taking drugs as prescribed
NICE guidelines say the healthcare professional should ask the carer for their views 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 if possible.
The person should take the drugs in the amounts and way prescribed by the doctor (for example, at bedtime or with food). The person may find it helpful to use 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 like this.
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 extra tablets, but should just 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.
How much is a normal dose?
The dose prescribed varies from person to person. Usually someone will start on a low dose, which will be gradually increased to make the treatment work better. 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 is available in 5mg or 10mg solid and orodispersible tablets. It also comes as a solution.
- Donepezil 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 comes in capsules from 1.5mg to 6mg and as a solution. 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 rivastigmine taken by mouth is 12mg.
- Rivastigmine skin patches are also available. These deliver daily doses of 4.6mg, 9.5mg or 13.3mg, with fewer side effects than the capsules. Patches may be better for people who find it hard to take medication by mouth. Only one patch should be used at any one time and a new patch should be put on a different area of the skin, to avoid the person getting a rash.
- The recommended starting dose for galantamine is 8mg each day for four weeks, increasing to 16mg a day for another four weeks, and then kept at a dose of between 16 and 24mg daily.
- Galantamine comes in different forms including a twice-daily solution, and tablets of 8mg and 12mg. Slowrelease capsules (that have XL after the drug name) are available in doses of 8mg, 16mg and 24mg and only need to be taken once a day.
- The maximum licensed total daily dose for galantamine is 24mg.
- Memantine comes in various forms: as solid and soluble tablets ranging from 5mg to 20mg, and as a solution.
- 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.