Prescribing for Alzheimer's disease

See here for clinical referral guidelines for the initial assessment and diagnosis of Alzheimer’s disease: South Devon and Torbay and South Hams and West Devon

Only specialists in the care of patients with dementia should make the diagnosis of Alzheimer's disease, assess whether the individual is suitable for treatment and initiate treatment where appropriate.

Assessing the severity of Alzheimer's disease and the need for treatment should not rely solely on cognition scores in circumstances in which it would be inappropriate, for example with patients with learning disabilities or language differences.

The specialist should seek the carer’s views on the patient’s condition at baseline and at any follow-up.

The Mini Mental State Examination (MMSE) which has been used to define dementia severity is no longer freely available for inclusion in the formulary. NICE guidance NG97 and TA217 do not recommend specific tools for measuring the severity of Alzheimer’s disease. It is recognised that clinicians are more likely to consider global functioning, quality of life, and the impacts on people’s daily activities in the review of patients with an established diagnosis.

The Neuropsychiatric Inventory has been suggested as a means of assessing a patient’s dementia and the impact on others through a questionnaire administered to a caregiver who knows the patient well. The Inventory is not freely available for inclusion in the formulary.

NICE guidance NG97 includes the current treatment recommendations for acetylcholinesterase inhibitors and memantine (see below). This guidance includes a partial update to NICE TA217 Donepezil, rivastigmine, galantamine and memantine for the treatment of Alzheimer’s disease.

See section 4.11 Drugs for dementia

• The three acetylcholinesterase (AChE) inhibitors donepezil, galantamine and rivastigmine as monotherapies are recommended as options for mild to moderate Alzheimer's disease
• Memantine monotherapy is recommended as an option for patients with:
  • moderate Alzheimer's disease who are intolerant of or have a contraindication to AChE inhibitors or
  • severe Alzheimer's disease
• For patients with an established diagnosis of Alzheimer’s disease who are already taking an AChE inhibitor:
  • consider memantine in addition to an AChE inhibitor if they have moderate disease
  • offer memantine in addition to an AChE inhibitor if they have severe disease
• If prescribing an AChE inhibitor (donepezil, galantamine or rivastigmine), start treatment with the drug with the lowest acquisition cost. However, if this is not suitable, an alternative AChE inhibitor can be prescribed

Do not offer the following specifically to slow the progression of Alzheimer’s disease except as part of a randomised controlled trial: diabetes medicines, hypertension medicines, statins, NSAIDs including aspirin.

The specialist should discuss with the patient and their carer(s) the benefits, side effects, frequency of dosing and monitoring requirements of their treatment.

There should be a suitable person identified to ensure concordance with treatment (e.g. relative or other carer), either by the specialist or GP. They should also make the carer aware of the nature of the effect of treatment and that it can be stopped if there are overly burdensome side effects.

Initial treatment

AChE inhibitors are recommended for patients with mild or moderate Alzheimer’s disease unless there is a contraindication to their use. Memantine may be an appropriate initial treatment for some patients (see Indications above).

The specialist should choose the most appropriate drug, initiate treatment, prescribe and monitor the patient until the dose is stabilised. Treatment should be prescribed by the GP after communication with the specialist and once the maintenance dose has been established.

Initiation of memantine in combination with an AChE inhibitor in patients with established Alzheimer’s disease

Primary care prescribers will be asked to initiate treatment with memantine in patients receiving AChE inhibitors. The specialist will provide advice on when to initiate treatment.

Patients diagnosed with mild Alzheimer’s disease by specialist and AChE inhibitor prescribed:

• There is no current recommendation for initiation of memantine in combination with an AChE inhibitor for mild Alzheimer’s disease
• In line with NICE guidance NG97, the GP will be asked to consider the addition of memantine in the future should the dementia progress to the point where the clinical picture is felt to present as moderate Alzheimer's disease and further pharmacological intervention is felt to be necessary
• Dose titration is required for memantine. The dose should be adjusted according to renal function and increased weekly as tolerated. For more information, see 4.11 Drugs for dementia

Patients diagnosed with moderate Alzheimer’s disease by specialist and AChE inhibitor prescribed:

• In line with NICE guidance NG97 memantine should be considered in addition to AChE inhibitor in patients with moderate Alzheimer’s disease, the GP will be asked to start memantine at an appropriate time point (for example three months after the first prescription for an AChE inhibitor).
• Dose titration is required for memantine. The dose should be adjusted according to renal function and increased weekly as tolerated. For more information, see 4.11 Drugs for dementia

Specialist advice and review

The specialist should specify any necessary monitoring and review dates at clinically relevant time intervals for both the GP and specialist team and any other patient specific information.

Specialist services will provide advice and, if appropriate, undertake a treatment review in response to the following situations:

• The GP considers the patient is experiencing side effects from the currently prescribed AChE inhibitor and would like advice on alternatives or discontinuation
• Additional neuropsychiatric symptoms or challenging behaviours have arisen and the GP feels that further assessment by secondary care older people's mental health services is warranted

Whilst the three AChE inhibitors (donepezil, galantamnine and rivastigmine) are only licensed in the UK for the treatment of mild or moderate dementia, research evidence has shown that they can also have a beneficial effect in patients with a severe dementia as well (see NICE guidance NG97). Therefore, they are usually not stopped until either:

1. Unacceptable side-effects occur. Though patients often tolerate the gastro-intestinal effect of these drugs better in the later stages of dementia, clinical experience has shown that sometimes if agitation is a problem, stopping these drugs can alleviate this. Review may also be required if bradycardia is a concern. OR
2. The patient's dementia deteriorates to such an extent, or other co-morbidities occur such as terminal illness, that continuing the drug is no longer clinically useful. Treatment should be continued only when it is considered to have a worthwhile effect on cognitive, global, functional or behavioural symptoms.

These decisions should be discussed with the family / carers and it is good practice to wean the medication off, e.g. reducing the dose by 50% for a month and then stopping. The patient then can be monitored over the next couple of weeks for signs of deterioration and the drug restarted if needed, although return to the previous level of functioning may not be achieved.

Contact details for the Specialist Teams

Devon Partnerships Trust

Contact details for the Older People’s Community Mental Health Teams and the Devon Memory Service can be found here

Livewell Southwest

Mental Health Specialist Pharmacists 01752 434723 or 01752 439006