Treatment of Degenerative Diseases of the CNS Flashcards
Parkinson’s Disease
S/S: (dyskinesias, or extrapyramidal symptoms)
depression
tremors
muscle rigidity (difficult to smile) (stiffness all over)
drooling
bradykinesia
chewing/swallowing difficulties
shuffling gait (wider stance)
postural instability
insufficient dopamine in CNS
dopamine slows impulses
acetylcholine (Ach) has excitatory effects
meds help restore balance between dopamine and acetylcholine (ACH) in brain
Prototype antiparkinson’s drug & adverse effects
Levodopa
a dopaminergic drug
dopamine cannot cross blood-brain barrier
levodopa can cross blood-brain barrier (a little, 1%)
levodopa is often combined with carbidopa-freely crosses
carbidopa prevents breakdown of levodopa in GI system and helps it enter brain
combined form is amantadine (Symmetryl) decrease freely floating dopamine outside brain
orthostatic hypotension
NVD, anorexia, dysphagia
involuntary movements
headache, anxiety, nightmares
anticholinergic effects (dry mouth, skin, unrinary retention)
psychosis (20% of patients)
leukopenia, hemolytic anemia
hemolytic anemia
on-off effects (migh take more frequent does to prevent)
Prototype antiparkinsons contraindications/interventions
glaucoma-closed angle
psychosis
heart, lung, renal, liver diseases
peptic ulcers (gastric ulcers)
severe HTN
drug interactions:
MAOIs, tricyclic antidepressants
high-protein foods-decrease absorbstion)-they should be on low protein diet with this med
interventions: monitor kidney, liver functions
safety measures
narrow-angle glaucoma/psychiatric status
watch for orthostatic hypotension
monitor for toxicity
teach to D/C slowly
maintain low-protein diet
takes several months to work
dopamine agonists
directly activate dopamine receptors
less effective
used early in disease
more adverse effects than levodopa/carbidopa
Prototype: (Mirapex)
Adverse effects:
common:
hallucinations
dizziness, drowsiness, sleep attacks
nausea
orthostatic hypotension
blood dyscrasias
dopamin agonist cautions/interventions
use with caution if patient has:
renal or liver disease
cardiac disease
CNS depressants
psychosis
dyskinesias
Nursing Interventions:
monitor BP – safety (Tilts-check sitting & standing)
monitor for tardive dyskinesia (smacking or sticking tounge out)
assess for psychosis or depression
avoid CNS depressants
teach it takes months for improvements
report hallucinations or dyskinesias (toxicity)
Dopamine Receptor Agonists
Prototype: (Symmetrel)- starts working quickly compared to others
increases release and blocks reuptake of dopamine (so stays there longer)
only works for several months
Adverse effects:(most are CNS related)
dizziness, drowsiness, confusion
irritability, headache
can exacerbate psychosis(suicical thoughts)
Contraindications:
closed-angle glaucoma, CHF
Catecholamine O-methyltransferase (COMT) inhibitors
COMT is an enzyme that degrades catecholamines
2 COMT inhibitors:
entacapone (Comtan)
tolcapone (Tasmar)
prevents destruction of levodopa in peripheral tissues to increase availability to brain
not used alone
Adverse effects: drowsiness, dizziness, hepatotoxicity, liver toxicity?
Monoamine Oxidase Inhibitors (MAOIs)
MAO is enzyme that metabolizes catecholamines to inactive compounds
MAO-A acts on norepinephrine and serotonin (acts on depression)
MAO-B inactivates dopamine in brain
Prototype MAO-B Inhibitor: selegiline (Eldepryl)
same adverse effects as levodopa
must avoid foods containing tyramine: aged of fermented, like cheeses, beer, meats, caffine, chocolate)
Anticholinergics
Cholinergic = parasympathomimetic (not reccomended for older patients-problems with confusion, dillusion)
help restore balance between Ach and dopamine by blocking Ach receptors in brain
Prototype: (Cogentin)- allows dopamine to work better adverse effects: dry mouth, constipation, urinary retention, confusion, sedation paralytic ileus (listen to bowel sounds)
Anticolinergic prototype contraindications/interventions
Cogentin
contraindications:
closed-angle glaucoma
myasthenia gravis
tardive dyskinesia
GI or urinary obstruction
peptic ulcers
tachycardia
age < 3 years
patients with psychosis
drug interactions:
other anticholinergics (added toxicity)
sedatives (more tired)
antidiarrheals (slow motility & decrease absorbstion)
nursing interventions:
monitor for paralytic ileus
monitor for improvement of symptoms
teach to not expect improvements in bradykinesia
Alzheimer’s Dementia (5-10 yr expectincy)
Cholinesterase inhibitors
indirect-acting parasympathomimetics
when cholinesterase is inhibited, acetylcholine elevates-excititory
Prototype: (Aricept)-given early in dementia
works by raising acetylcholine (Ach) concentrations in the brain
adverse effects:
NVD or constipation (main reason ppl stop taking it)
anorexia with weight loss
muscle cramping and arthralgia
syncope
fatigue
atrial fibrillation
severe bradycardia
seizures
Alzheimers prototype contraindications/interventions
contraindications
bradycardia, sick sinus syndrome
asthma, COPD
GI bleeding
hypotension
history of seizures
drug interactions
any meds metabolized by CYP 450 enzymes
NSAIDs
nursing interventions:
overdose can cause cholinergic crisis
monitor liver and renal function
monitor for co-morbidities
depression, anxiety, psychosis
do not abruptly D/C med
oral hygiene for dry mouth, fluids and fiber for constipation
Namenda
also a cholinesterase inhibitor
affects abnormally high levels of glutamate
prevents glutamate from causing excitatory actions
Multiple Sclerosis (usually have a while before diagnosed)
neurodegenerative disease
removes myelin sheath by inflammation
creates plaques in white matter
probably an autoimmune problem- thought to stim from a virus, thats why hard to tell who gets it)
drugs manage symptoms, no cure. start to have bladder and control problems.
immunomodulators
they work in different ways to treat MS
some stimulate immune response
some suppress immune function
some prevent WBCs from migrating to CNS
reduces inflammation
slows demyelination
decreases plaque formation
adverse effects:
flu-like symptoms
liver impairment
leukopenia
depression
thyroid dysfunction
heart failure
another treatment: high dose corticosteroids, not longer than 3 weeks, no more than 3 times a year.
