Antiparkinsonism Agents Flashcards
What is parkinsonism?
- General syndrome of muscle tremors, bradykinesia, altered gait, etc. regardless of cause
- Could be related to medications
What is Parkinson’s Disease?
- Progressive chronic neurological disorder
- Related to damaged neurons in basal ganglia cells
- May develop in people of any age
- Usually affects those past midlife - entering their 60s
- Cause is unknown - thought to be a combo of genetic and environmental factors
- No cure
- Therapy manages signs and symptoms
What is the management of care of patients with Parkinson’s Disease?
- Drug therapy is aimed at restoring balance between dopamine and cholinergic neurons
- Encourage patients to:
Be as active as possible
Perform exercises
Maintain independence with ADLs as long as possible
Follow drug protocols - Patient and family need education on drug therapy and psychological support
Lifespan Considerations for Antiparkinsonism Agents
In Children
- Safety and effectiveness not established
- Incidence in children is very small
- They DO experience parkinsonism symptoms from drug effects
- Diphenydramine is the drug of choice
Lifespan Considerations for Antiparkinsonism Agents
In Adults
- Devastating progression
- Inform provider of ANY herbal/alternate therapies
- Use contraception in childbearing age
- Use alternate method to feed infant
Lifespan Considerations for Antiparkinsonism Agents
In Older Adults
- Increases with age
- Increased adverse effects
- Drugs aggravate glaucoma, BPH, constipation, cardiac problems, and COPD that often are seen in this population
- May need frequent dose adjustments
- May need other drugs to counteract effects of these drugs
Dopaminergic Agents
Drug Names
🔴 Amantadine
🟠 Carbidopa-levodopa
🟡 Levodopa
🟢 Rasagiline
🔵 Ropinirole
Dopaminergic Agents
Mechanism of Action
- Promote dopamine synthesis
- Activate dopamine receptors
- Prevent dopamine breakdown
- Decrease degradation of levodopa (carbidopa)
- Help to restore balance between inhibitory (dopamine) and stimulating (acetylcholine) neurotransmitters
Dopaminergic Agents
Indications
Relief of the signs and symptoms of idiopathic Parkinson’s disease
Levodopa
- Naturally created by the body
- Precursor to dopamine
- Mainstay of treatment for parkinsonism
- Crosses the blood brain barrier where it is converted to dopamine
- Almost always given as combo drug with carbidopa
- Carbidopa decreases the amount of levodopa needed to reach a therapeutic level in the brain
- The dosage of levodopa can be decreased with the added carbidopa, reducing adverse effects
Dopaminergic Agents
Contraindications
Absolute:
* Allergy
* Lactation
* Angle closure glaucoma (inc. in eye pressure - exacerbates this)
Cautions:
* CV disease: orthostatic hypotension, arrhythmias
* Bronchial asthma: could trigger bronchospasm
* History of Peptic Ulcer
* Urinary Tract Obstruction
* Psychiatric disorders
* Pregnancy
Dopaminergic Agents
Adverse Effects
- CNS: anxiety, nervousness
- Peripheral effects: anorexia, nausea, dysphagia, urinary retention
- Cardiac: arrhythmias, orthostatic hypotension
Dopaminergic Agents
Drug Interactions
- MAOIs: STOP 2 WEEKS before taking dopaminergics - ⬆️risk of hypertensive crisis
- Vitamin B6
Carbidopa-Levodopa: Iron Salts
Rasagiline: tyramine containing foods (inc. risk of hypertensive crisis); St. John’s Wort (inc. risk of serotonin syndrome); Meperidine; Acetaminophen (inc. risk of liver toxicity)
Dopaminergic Agents
Assessment
History:
* Check for all contraindications and cautions
Physical:
* Skin
* CNS: Level of orientation, affect, reflexes, bilateral grip strength, gait, tremors, spasticity
* Lung sounds
* Vitals
* Bowel sounds
* Urine output
* Palpate bladder
Labs:
* Liver and Renal function tests
* CBC
Dopaminergic Agents
Nursing Diagnoses/Conclusions
- Altered thought processes (r/t CNS effects)
- Urinary retention (r/t dopaminergic effects)
- Constipation risk (r/t dopaminergic effects)
- Injury risk (r/t CNS effects and orthostatic hypotension)
- Knowledge Deficit
Dopaminergic Agents
Implementation/Patient Teaching
- Arrange to decrease dose of the drug if therapy has been interrupted for any reason
- Evaluate disease progression, record for reference
- Give the drug with meals to reduce GI effects
- Bowel program if constipation is severe
- Void before administration if urinary retention is an issue
- Safety precautions for CNS or vision issues
- Involve support system
- Report: worsening symptoms, severe constipation or N/V, urinary retention, abdominal pain, severe dizziness, hallucinations, confusion, depression, agitation
- Avoid tyramine containing foods
- Do not miss doses or stop abruptly
- Encourage follow up appointments
- Avoid driving until CNS effects are known
Anticholinergic Agents
Drug Names
To treat parkinsonism
Bentropine
Diphenhydramine
Anticholinergic Agents
Mechanism of Action
Synthetic drugs with greater affinity for cholinergic receptor sites in the CNS rather than the peripheral nervous system
Anticholinergic Agents
Indications
- Treatment of parkinsonism
- Relief of symptoms of extrapyramidal disorders associated with use of some drugs
Anticholinergic Agents
Contraindications
Absolute:
* Allergy
* Any condition exacerbated by blocking the PNS: Glaucoma, GI obstruction, GU obstruction, myasthenia gravis, and prostatic hypertrophy
Cautions:
* Tachycardia, hypertension
* Pregnancy and lactation
* Individuals at risk for heat exhaustion
Anticholinergic Agents
Adverse Effects
- CNS effects and periperal anticholinergic effects
- Works mostly in the CNS: dizziness, confusion, etc.
Anticholinergic Agents
Drug Interactions
- Other anticholinergics
- Antipsychotics: TCAs, phenothiazines
Anticholinergic Agents
Assessment
History:
* Check for all cautions and contraindications
Physical:
* Level of orientation and affect, reflexes, bilateral grip strength, gait, tremors, and spasticity
* Monitor pulse, blood pressure, and cardiac output
* Auscultate bowel sounds
* Urinary output, palpate bladder
Labs:
* Renal and Liver function tests
Anticholinergic Agents
Nursing Diagnoses/Conclusions
- Dry oral mucous membranes (r/t anticholinergic effects)
- Risk for impaired thermoregulation (r/t anticholinergic effects)
- Impaired urinary elimination (r/t genitourinary effects)
- Constipation risk (r/t GI effects)
- Altered thought processes (r/t CNS effects)
- Injury risk (r/t CNS effects)
- Knowledge Deficits
Anticholinergic Agents
Implementation
- Arrange to decrease or discontinue if dry mouth becomes so severe that swallowing becomes difficult
- Give drug with caution and arrange for decrease in dose in hot weather or exposure to hot environments
- Give drug with meals if GI upset is an issue, before meals if dry mouth is a problem, and after meals if drooling occurs and causes nausea
- Bowel program if constipation is severe
- Void before taking drug
- Safety precautions for CNS effects
- Stay hydrated
- Avoid other CNS depressants
- Encourage follow up appointments
Adjunctive Agents
Drug names
Entacapone: used with carbidopa-levodopa to increase plasma concentration and duration of action of levodopa; use barrier contraceptives
Safinamide (MAOI): with with carbidopa-levodopa in patients with Parkinson’s having “off” episodes
Selegiline (MAOI): used with carbidopa-levodopa after patient has shown signs of deteriorating response to treatment:
Tolcapone: works with carbidopa-levodopa to increase plasma levels of levodopa: use barrier contraceptives, avoid in hepatic dysfunction
