Drugs for Parkinsonism and Alzheimer Disease Flashcards
a chronic, progressive, neuro disorder that affects the extrapyramidal motor tract, which controls posture, balance, and locomotion (low dopamine)
parkinson disease (PD)
major features of PD
rigidity, bradykinesia, gait disturbances, and tremors
chest and head thrust forward with knees and hips flexed, shuffling gait, and absence of arm swing, and masked facial expressions
pill rolling tremors
1mill americans, 2% chance, men/women equal
frequently occurs as an adverse reaction to certain drugs
pseudoparkinsonism
parkinsonism symptoms can also result from what
poisons (carbon monoxide and manganese) or from disorders (encephalitis, infections, stroke, trauma)
inhibitory neurotransmitter
dopamine (DA)
excitatory neurotransmitter
acetylcholine (ACh)
what are the 5 categories of drugs to treat PD
1) anticholinergics
2) dopaminergic replacement
3) dopamine agonists
4) MAO-B inhibitors
5) COMT inhibitors
increase the effects of DA in the brain by reducing the effects of ACh. This reduces the rigidity and some of the tremors characteristic of PD but has minimal effect on bradykinesia.
parasympatholytics that inhibit the release of ACh
anticholinergics
e.g. trihexyphenidyl and benztropine
anticholinergics are contraindicated in ___
glaucoma
what can be given for mild PD symptoms
diphenhydramine
effective in diminishing symptoms of PD and increasing mobility; short half-life
large doses are needed to achieve a response
levodopa
enzyme dopa decarboxylase converts levodopa to DA in the brain, but also converts 99% of levodopa to be converted to DA before it reaches the brain.
an alternative drug used in combo because so much levodopa is metabolized before it reaches the brain
inhibits the enzyme dopa decarboxylase (more levodopa reaches the brain)
carbidopa
by combining levodopa with carbidopa, more DA reaches the basal ganglia and ___ doses of levodopa are required to achieve the desired effect.
smaller
**advantage
disadvantage of combining carbidopa/levodopa
more side effects (N/V, dystonic movement, and psychotic behavior)
angioedema, palpitations, and orthostatic hypotension may occur
stimulate DA receptor activation and provide relief from PD symptoms such as tremor and rigidity
dopaminergics
DA agonists
e.g. bromocriptine and apomorphine hydrochloride
how to relieve dry mouth from anticholinergic agents
hard candy, ice chips, or sugarless chewing gum
the enzyme MAO-B causes catabolism (breakdown) of DA.
inhibit MAO-B and thus prolongs the action of levodopa
Monoamine Oxidase B Inhibitors (MAO-B inhibitors)
**selegiline hydrochloride
large doses of selegiline may also inhibit MAO-A, an enzyme that promotes metabolism of tyramine.
What foods contain tyramine?
what can ingestion of these foods cause, if not metabolized by MAO-A?
aged cheese, red wine, and bananas
hypertensive crisis
the enzyme Catechol-O-Methyltransferase (COMT) inactivates DA.
When taken with levodopa they increase the amount of levodopa concentration in the brain
COMT Inhibitors
**tolcapone
Check LFTs
an incurable dementia illness characterized by chronic, progressive neurodegenerative conditions with marked cognitive dysfunction
Alzheimer Disease
patho of alzheimer disease
degeneration of cholinergic neuron and deficiency in ACh
neuritic plaques that form mainly outside of the neurons and in the cerebral cortex
protein accumulation in high levels that may contribute to neuronal injury
the etiology of alzheimer disease is ____
unknown
how long from diagnosis of alzheimer disease does death usually occur?
4-8 years
symptoms of alzheimer disease
memory lapses, irritable, moody, personality and behavioral changes
what age does alzheimer disease usually get diagnosed
45-65
how many americans have alzheimers
5.4mill
alzheimers is the ___ leading cause of death
6th
this drug class treats alzheimers by allowing for more ACh and inhibits an enzyme that breaks down ACh
AChE inhibitors
** donepezil, memantine, galantamine, rivastigmine (LFTs)
