Flashcards in Dementia drugs Deck (17):
delirium vs dementia
Cognitive dysfunction that occurs over a shorter time frame with notable confusion, particularly acute onset changes that may last hours to days and even up to weeks, may represent delirium
The most common causes of dementia include:
• Alzheimer's disease
• Vascular or multi-infarct dementia
• Parkinson’s disease
• Dementia with Lewy bodies
Current FDA-approved medications for the treatment of Alzheimer’s disease
mild to moderate cases:
Donepezil, Galantamine and Rivastigmine
moderate to severe Alzheimer’s disease:
Memantine, an NMDA receptor partial antagonist
• Anticholinergic medications have long been observed to commonly cause memory impairment and confusion.
• The cholinergic hypothesis postulates that the destruction of basal forebrain cholinergic neurons and the resultant deficit in cholinergic transmission in the brain is the basis for the neurologic deficits associated with Alzheimer’s disease.
thus acetylcholinesterase (AChE) inhibitors for Alzheimer disease therapy.
(a.k.a. the anti-cholinesterases) are agents that inhibit the cholinesterase enzyme from breaking down the neurotransmitter, acetylcholine.
s enhanced cholinergic transmission is felt to be responsible for the reduction of the signs and symptoms of Alzheimer's dementia placed on drugs of this class.
antidote to anti-cholinergic poisoning
AChEIs are also used as an antidote to anti-cholinergic poisoning as can occur with organophosphate poisoning and nerve gas exposure.
potent parasympathetic effects of AChEIs
bradycardia, hypotension, increased urination, increased lacrimation, broncho-constriction, GI tract hypermotility with nausea and vomiting.
Nerve gases MOA
Nerve gases irreversibly inhibit the enzyme acetylcholinesterase; this results in a chronically high level of acetylcholine at cholinergic synapses throughout the body, thus chronically stimulating acetylcholine receptors throughout the body.
• Donepezil (Aricept) is a centrally acting reversible acetylcholinesterase inhibitor.
• Its main therapeutic use is in the treatment of Alzheimer's disease where it is used to increase cortical acetylcholine.
• Donepezil has been tested and used as an off-label treatment for other cognitive disorders including both Lewy body dementia and vascular dementia.
Donepezil/ Aricept SE
• The most commonly experienced side effects of Donepezil and the other agents in this class of drugs include bradycardia, nausea, diarrhea, anorexia, abdominal pain and vivid dreams.
• There are at least two studies that suggest that Donepezil can potentially increase and improve the vocabulary and expressive language of children affected with autism.
• Rivastigmine (Exelon) is another centrally acting, reversible acetylcholinesterase inhibitor.
• Rivastigmine is approved for treatment of mild to moderate dementia due to Alzheimer’s disease and mild to moderate dementia due to Parkinson's disease.
• The drug can be administered orally or via a transdermal patch with the patch form reducing the prevalence of side effects.
The presence of hallucinations appears to be a predictor of especially strong responses to Rivastigmine, both in Alzheimer’s and Parkinson's disease patients. ANd younger age of onset.
• Galantamine is indicated for the treatment of mild to moderate Alzheimer's disease and mild to moderate vascular dementia.
• Along with other cholinergics or acetylcholinesterase inhibitors such as Huperzine A, Galantamine has also been used as a "brain enhancer" to improve memory in brain-damaged adults
Acetylcholinesterase inhibiting drug O.D.
• Overdosage of the acetylcholinesterase inhibiting drugs may give rise to severe side effects such as nausea, vomiting, salivation, sweating, bradycardia, hypotension, convulsions and circulatory collapse.
• The anticholinergic drug atropine is indicated as an antidote for overdose.
• Abnormal function of glutamatergic neurotransmission is hypothesized as another factor contributing to the etiology of Alzheimer's disease.
• Targeting the glutamatergic system, specifically the NMDA receptors, is a new approach to the treatment of Alzheimer's.
• Memantine is the first drug in a novel class of medications which acts to block NMDA glutamate receptors.
Memantine/ Namenda MOA
• By binding to NMDA receptors, Memantine is able to inhibit the prolonged influx of Ca2+ ions which appears to play an important role in neuronal excitotoxicity.