A 71-year-old man is diagnosed with early Alzheomer’s disease and staned on donepezil, and over the past few months his wife has noticed a gradual fall off in his appetite. Apart from that there has been an improvement in his mental state score.
Whoch of the foffowing represents the mode of action of donepezil?
Acetylcholinesterase inhibitor
B Dopamine agonist
c Nicotinic receptor agonist
D NMDA antagonist
E Noradrenaline reuptake inhibitor
Explanation
Th a ·wer os ftcerylcholinesterase mh1blto•
Donepezil is a specific reversible acetylcholinesterase inhibitor used in the treatment of Alzheimer’s. Prominent side effects .nclude those associated with choline<goc activation. including Gl upset, (diarrhoea, nausea and vomitong), and urinary oncontinence.
Dopamine agonist, (Option B). is incorrect. Dopamine agonists such as ropinirole are commonly used in the treatment of Parkinson’s disease, and may result in increased risk of hallucinations I agitation in patients with dementia.
Nicotinic receptor agonist, (Option C), is incorrect Galantamine, another reversible inhibitor of acetylcholinesterase also enhances the acuon of acetylcholine on nicotinic receptors, probably through allosteric receptor binding.
NMOA antagonist, (Option D), is incorrect. Memanune is an NMOA antagonost. which is known to reduce glutamate toxicoty and actovation.
Noradrenaline reuptake inhibitor, {Option E). is incorrect. Noradrenaline reuptake inhibitors such as reboxetine are used as antidepressants and for the treatment of attention deficit hyperactivity disorder.