parkinsons and alzheimers Flashcards
parkinson’s disease
Affects dopamine-producing neurons in the brain
Caused by an imbalance of two neurotransmitters
Dopamine
Acetylcholine (ACh)
theories about the cause of PD
Viral Infection Blows to the Head Brain Infection Atherosclerosis Exposure to Certain Drugs Environmental Factors Genetic component
physiology of PD
Dopamine inhibits neurons in the striatum
Ach (acetylcholine) excites neurons in the striatum
As a result, excitatory effects of Ach go unopposed and dyskinesias (disturbed movement) results
hallmark signs of PD
Tremors Rigidity Postural instability Drooling Bradykinesia (slowed movement) Staggering gait
aim of PD drug therapy
Increase stimulation to dopamine receptors
Dopaminergic Agents
Block receptors for Ach
Anticholinergic Agents
dopaminergic drugs PD
Increase effects of dopamine at receptor sites
Effects of drugs diminish over time- dose dependent
Treatment of choice for advanced disease, elderly
Given orally
levodopa
Levodopa is converted to dopamine in the brain by an enzyme (decarboxylase) since dopamine cannot cross the blood-brain barrier
NOT DOPAMINE
only ~2% reaches the brain
levodopa/carbidopa
To increase the % of Levodopa that reaches the brain, Levodopa is combined with Carbidopa
Carbidopa inhibits decarboxylation of levodopa peripherally, making more of levodopa (10%) available to the CNS
nursing considerations PD drugs
Therapeutic effects may take months to develop
Effects of drug may diminish over time
Levodopa may darken sweat and urine
anticholinergics
Oppose effects of Ach at receptor sites; help restore chemical balance
Better tolerated but less effective than levodopa
Used in combination with other agents
PD safety
falls
aspiration
postural hypertension
alzheimers
Is a form of dementia that results from degeneration of (cholinergic) neurons in the brain
Characterized by the formation of neuritic plaques and neurofibrillary tangles
aim of drug therapy Alzheimer’s
slow disease progression and preserve independent function for as long as possible
cholinesterase inhibitors
NMDA Receptor Antagonist
cholinesterase inhibitors
Mechanism of action is to prevent breakdown of Ach
Not all patients respond to therapy
cholinesterase inhibitors SE
GI most common: nausea, vomiting, dyspepsia, diarrhea Weight loss Dizziness and headache also common Bradycardia and/or hypotension Pupil constriction
