Dementia Pathways. For Primary Care in ireland
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  • Advise patients to use a medicine dispenser or to ask the pharmacist to blister pack the medications.
  • It is likely that the patient will have been commenced on a Cholinesterase Inhibitor e.g. Donepezil (Aricept), Rivastigmine (Exelon), Glanatamine (Reminyl)
    • It is important to manage the patients and their families’ expectations of these medications. They are unlikely to see a significant improvement in memory or function on the treatment but they will hopefully see stabilisation of the person’s condition for 6-9 months.

 

Cholinesterase Inhibitors

 

Licenced for use in mild to moderately severe Alzheimer’s Disease.

 

Drug

Starting Dose

Titration Period

Dose Increase Per Titration

Usual Max Dose

Donepezil (Aricept)

5mg OD

4-6 weeks

5mg

10mg OD

Rivastigmine

Tablet

(Exelon)

1.5mg BD

2-4 weeks

1.5mg BD

3- 6mg BD

Rivastigmine Patch

(Exelon)

4.6 mg/24 hr

4-6 weeks

 

9.5 mg/24 h

Galantamine (Reminyl)

*oral solution available

4mg BD

4-6 weeks

8mg daily

16-24mg daily

 

Side effects:

The most common side effects are nausea and GI upset which are often dose related and improves over time or with dose reduction. The GI symptoms can occasionally be overcome by use of a topical rivastigmine patch. Less common side effects include heart arrhythmias, increased dreaming and nightmares.

Due to the potential to cause arrthymias, prior to commencing a cholinesterase inhibitor a baseline ECG is recommended – sometimes patients are on a beta-blocker and the addition of a cholinesterase inhibitor in individuals with conduction block could precipitate heart block or lead to syncope.

 

Memantine

Memantine is NMDA receptor antagonist, not an acetylcholinesterase inhibitor. Memantine is licensed in moderate to severe Alzheimer ’s disease. Memantine may occcasionally be prescribed in addition to an acetylcholinesterase inhibitor.

Although memantine is occasionally used to manage aggression and agitation in PwD, trials to date have not found evidence to support its use to manage these symptoms.

The maximum daily dose is 20 mg per day. In order to reduce the risk of undesirable effects, the maintenance dose is achieved by upward titration of 5 mg per week over the first 3 weeks as follows:

 

Example of a memantine titration schedule

  • Week 1 (day 1-7): 5mg OD  (1/2 a 10mg tablet)
  • Week 2 (day 8-14): 10mg daily
  • Week 3 (day 15-21): 15mg daily
  • Week 4 on: 20mg daily

 

The recommended maintenance dose is 20 mg per day.

 

Side Effects include:

Headaches dizziness, constipation, confusion, decreased renal function.

Although memantine is generally well-tolerated, some persons with dementia, particularly those with Lewy body pathology, may be susceptible to developing adverse effects which include increased aggression, new delusions, hallucinations or agitation.

 

Note: In patients with moderate renal impairment (creatinine clearance 30 - 49 ml/min) daily dose should be 10 mg per day. If tolerated well after at least 7 days of treatment, the dose could be increased up to 20 mg/day according to standard titration scheme. In patients with severe renal impairment (creatinine clearance 5 – 29 ml/min) daily dose should be 10 mg per day.