cns -antiparkinsonian drugs discuss the signs and symptoms exhibited by a patient with parkinson’s...

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


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


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


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


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


Bradykinesia

Loss of automatic movements: Blinking of 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


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


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)


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

CNS -- Antiparkinsonian DrugsNursing 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 DrugsNursing 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 familySafetyEffect 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 DrugsMonitoring 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.

cns -antiparkinsonian drugs discuss the signs and symptoms exhibited by a patient with parkinson’s...

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