Mild to moderate Alzheimer's disease may be treated using one of the cholinesterase inhibitors (donepezil, rivastigmine, galantamine), and the glutamate antagonist memantine is licensed for use in moderate to severe cases.

Dosage regimen

* Donepezil: 5mg once daily at bedtime, increased if necessary after one month to 10mg daily; max. 10mg daily.

* Rivastigmine: initially 1.5mg twice daily, increased in steps of 1.5mg twice daily at intervals of at least 2 weeks according to response and tolerance; usual range 3-6mg twice daily; max. 6mg twice daily.

* Galantamine: initially 4mg twice daily for 4 weeks increased to 8mg twice daily for 4 weeks; maintenance 8-12mg twice daily. Modified release preparation; initially 8mg once daily for 4 weeks increased to 16mg once daily for 4 weeks; maintenance 16-24mg daily.

* Memantine: initially 5mg in the morning, increased in steps of 5mg at intervals of 1 week up to max. 10mg twice daily.

Patient's knowledge of the medicine's use

* Drug treatment aims to increase patients' alertness, improve mood, restore confidence and slow disease progression.

* Ensure carers are educated on each medicines use.

* Remind carers to check whether any OTC medicines the patient uses are safe.

* Galantamine and rivastigmine need to be taken with or after food.

Is the medicine working?

* Behavioural and functional assessments are undertaken.

* The Mini Mental State Examination (MMSE) assesses cognitive outcomes.

* Treatment should be evaluated three months after starting, to assess whether there is a beneficial response. If there appears to be no benefit, the drug should be stopped but a re-evaluation carried out six to eight weeks later to ensure there is no deterioration in symptoms.

* Responsive patients should be assessed every six months and treatment should be discontinued when assessment shows no further benefit or MMSE scores fall below 10.

* Check any compliance problems. Rivastigmine is available as an oral solution and memantine is available as oral drops for those with problems swallowing solid dosage forms.

Side effects

* Donepezil: nausea, vomiting, anorexia, diarrhoea, fatigue, insomnia, headache, dizziness, psychiatric disturbances, urinary incontinence, gastric and duodenal ulcers, pruritis and rashes.

* Rivastigmine: nausea, vomiting, diarrhoea, dyspepsia, anorexia, dizziness, headache and confusion.

* Galantamine: nausea, vomiting, diarrhoea, abdominal pain, dyspepsia, rhinitis, sleep disturbances, dizziness, headache, anorexia, weight loss and confusion.

* Memantine: constipation, headache and dizziness.

Monitoring

* Body weight should be monitored for all patients on rivastigmine.

* All the anticholinesterases have a potential to cause gastric ulcers. Monitor for any signs of bleeding and ensure OTC NSAIDs are not being taken.

Lifestyle

* NICE recommends that for less severe distress or agitation, non-drug interventions should be tried first.

* Aromatherapy with lemon balm (melissa) or lavender have shown benefits.

* Multisensory stimulation, massage and therapeutic use of music have shown beneficial effects.

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