Acetylcholinesterase inhibitors Flashcards
what are ACH inhibitors indicated for? (2)
1) Mild to moderate Alzheimer’s disease
2) Mild to moderate dementia in Parkinson’s disease (rivastigmine)
Outline the MoA of ACH inhibitors
1) ACH is essential to many brain functions including learning and memory. A decrease in activity of the brain’s cholinergic system is seen in Alzheimer’s disease and in the dementia associated with Parkinson’s disease.
2) These drugs inhibit the cholinesterase enzymes that break down acetylcholine in the CNS
3) This increases the availability of acetylcholine for neurotransmission, improve cognitive function and reduce the rate of cognitive decline
summarise the Important adverse effects with regards to ACH inhibitors
1) Common: Nausea, diarrhoea and vomiting- these adverse effects may resolve over time.
2) Patients with asthma or COPD may experience an exacerbation of symptoms.
3) Less common, but serious, peripheral effects include peptic ulcers and bleeding, bradycardia and heart block.
4) Central cholinergic effects may induce hallucinations and altered/aggressive behaviour
5) small risk of extrapyramidal symptoms and neuroleptic malignant syndrome.
Central cholinergic effects of ACH inhibitors may induce hallucinations and altered/aggressive behaviour. How can this be managed?
reduction of dose or discontinuation of therapy
Who should ACH inhibitors be used in caution with?
1) Asthma and COPD
2) Those at risk of developing peptic ulcers.
3) Avoided in patients with heart block or sick sinus syndrome.
4) Rivastigmine may worsen tremor in those with Parkinson’s disease
list some of the Important interactions that may occur with regards to ACH inhibitors
1) Concomitant therapy NSAIDs and corticosteroids may increase the risk of peptic ulceration
2) Use alongside antipsychotics may increase the risk of neuroleptic malignant syndrome
3) Bradycardia and/or heart block may occur when prescribed alongside other rate-limiting medications (e.g. β-blockers)
Who should ACH inhibitors be initiated by and why is a low dose initially prescribed?
1) prescribed by clinicians with experience in managing dementia or Parkinson’s disease.
2) low dose should be used to reduce the risk of adverse effects.
what are the Initial doses for the following drugs:
1) Donepezil
2) Rivastgmine
1) Donepezil 5 mg daily
2) Rivastigmine 1.5 mg 12- hrly
↳ ( Dose may be titrated up after 2–4 weeks)
what time of the day should donepezil be taken?
At night, before bed
Vivid dreams have been reported with the use of donepezil, how should this be managed?
Where this is problematic for patients, advise them to take the drug in the morning, rather than before bed
Outline the monitoring requirements for ACH inhibitors
1) Patients should be reviewed for adverse effects 2–4 weeks after initiation of treatment or dose adjustments.
2) At 3 months, repeat cognitive assessment should occur to assess treatment efficacy. Treatment should continue only where there is a worthwhile improvement in the patient’s symptoms
what serious side effect can glantamine cause and when should treatment be discontinued?
1) Serious skin reactions (including Stevens-Johnson syndrome and acute generalized exanthematous pustulosis)
2) discontinue at the first appearance of skin rash
what patient and carer advice should be provided to those prescribed glantamine?
patients are warned of the signs of serious skin reactions;advised to stop taking galantamine immediately and seek medical advice
Explain how rivastigmine patches should be applied
1) Apply patches to clean, dry, non-hairy, non-irritated skin on back, upper arm, or chest
2) Remove after 24 hours and place a new patch on a different area
3) Avoid using the same area for 14 days
Rivastigmine treatment should be interrupted if what side effect occurs?
if dehydration resulting from prolonged vomiting or diarrhoea occurs withhold until resolved—retitrate dose if necessary
