CNS -Antiparkinsonian Drugs
Discuss the signs and symptoms exhibited by a
patient with Parkinson’s Disease
Describe the actions and intended effects of
medications used to treat the signs and symptoms of
Parkinson’s Disease
CNS
Antiparkinsonian Drugs
Parkinson’s Disease:
Disease of the basal ganglia & related neuronal groups +
neurotransmitter deficiencies
“shaking palsy”
Bradykinesia – slowing down in the initiation & execution of
movement
Rigidity – increased muscle tone
Tremor at rest
Impaired postural reflexes
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Antiparkinsonian Drugs
Degeneration of dopamine-producing neurons in the
substantia nigra of the midbrain
Disrupts the balance of:
dopamine (DA) – neurotransmitter for normal functioning of
the extrapyramidal motor system (control of posture, support, and
voluntary motion)
Acetylcholine (Ach)
and the basal ganglia
Symptoms do not occur until 80% of the neurons in
the substantia nigra are lost
CNS Antiparkinsonian Drugs
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Antiparkinsonian Drugs
Five Stages
Flexion of affected arm - tremor / leaning toward unaffected
side
Slow shuffling gate
Increased difficulty walking – looks for support to prevent
falls
Further progression of weakness – assistance with
ambulation
Profound disability – may be confined to wheelchair
CNS
Antiparkinsonian Drugs
Tremor
First sign
Affects handwriting – trailing off at ends of words
More prominent at rest
Aggravated by emotional stress or increased concentration
“Pill rolling” – rotary motion of thumb and forefinger
NOT essential tremor – intentional
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Antiparkinsonian Drugs
Rigidity
Increased resistance to passive motion when
limbs are moved through their range of motion
“Cogwheel rigidity” -- Jerky quality –
intermittent catches of movement
Caused by sustained muscle contraction
Muscle soreness; feeling tired & achy
Slowness of movement due to inhibition of alternating
muscle group contraction & relaxation in opposing muscle
groups
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Antiparkinsonian Drugs
Bradykinesia
Loss of automatic movements:
Blinkingof eyes, swinging of arms while walking,
swallowing of saliva, self-expression with facial and
hand movements, lack of spontaneous activity, lack of
postural adjustment
Results in: stooped posture, masked face, drooling of
saliva, shuffling gait (festination); difficulty initiating
movement
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Antiparkinsonian Drugs
Drug Therapy
Correcting the imbalance of neurotransmitters within the CNS
Dopaminergic – enhance release or supply of dopamine (DA)
Anticholinergic – antagonize or block the effects of overactive
cholinergic neurons in the striatum
Monoamine Oxidase Inhibitor
Decreases MAO (the degradative enzyme for DA)
Results: DA levels are increased
Catechol-O-Methyl Transferase (COMT) Inhibitor
Betablocker
Antihistamine
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Anticholinergic Drugs: decrease the activity of
Ach
Benztropine (Cogentin)
Antihistamines – decreases rigidity
Benadryl
Betablockers – decreases rigidity
Inderal
Monoamine oxidase inhibitor (MAOI):
Selegiline (Eldepryl )
Catechol-O-Methyl Transferase (COMT)
Inhibitor
Entacapone (Comtan)
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Antiparkinsonian Drugs
Drug Therapy
Sinemet early in disease becomes ineffective
Early: DA receptor agonist -- directly stimulate DA receptors
Parlodel, Requip, Mirapex
Moderate to severe symptoms:
Sinemet is added to therapy
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Antiparkinsonian Drugs
CNS -- Antiparkinsonian Drugs
Nursing Process
Assessment
Head-to-toe
Neuro
GI/GU
Ability to swallow
Psychological and emotional coping
Parkinson progression
Medication History
Length of time on medications
Changes in medications and effects
Safety
Ability to perform ADLs independently
CNS -- Antiparkinsonian Drugs
Nursing Process
Nursing Actions
Exact timing of medication – cannot be administered
late
Oral doses given with food
Avoid foods in Vit B6 – reverse effects of levodopa
Wheat germ, whole grain cereals, muscle & glandular
meats (particularly liver), legumes, green leafy vegetables,
bananas
Force fluids >2,000 mL/day
High roughage, high fiber diet
CNS -- Antiparkinsonian Drugs
Patient Education
“Wearing off” – “On-Off” phenomenon – gradual
worsening of symptoms as medication begins to lose
effectiveness, despite maximal doses
“Drug Holiday” when levodopa no longer working effectively (usually
10-day period of hospitalization)
Community resources to assist patient and family
Safety
Effect on blood pressure –
Hypotension
Hypertensive crisis of MAOI accidentally taken
“Sleep attacks” – newer dopamine agonists (pramipexole &
ropinirole)
GI: Constipation – high fiber, high roughage, increased fluids
GU: urine color changes – brownish-orange (entacapone)
CNS – Antiparkinsonian Drugs
Monitoring Therapeutic Effects
Therapeutic Response:
Improved sense of well being
Ability to perform ADLs
Ability to concentrate and think clearly
Less intense parkinsonian manifestations
Observe for Adverse Effects:
Confusion, anxiety, irritability, depression, paranoia,
headache, weakness, lethargy, nausea, vomiting, anorexia,
palpitations, postural hypotension, tachycardia, dry mouth,
constipation, urinary retention, blurred vision, dark urine,
difficulty swallowing, and nightmares
CNS – Antiparkinsonian Drugs
Carbidopa in Parkinson’s disease is to be
used:
a. As successful monotherapy.
b. In conjunction with levodopa to block peripheral
conversion to dopamine.
c. To decrease the incidence of gastrointestinal side
effects associated with levodopa.
d. 2 and 3
CNS – Antiparksonian Drugs
Discuss the normal course of progression of
Parkinson’s disease. Include the rationale for drug
therapy to alleviate the symptoms.