Chapter 30

Agents Used to Treat Parkinson’s Disease

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Parkinson’s Disease

A neurological disorder characterized by: Muscle tremors Muscle rigidity Lack of coordination Drooling Shuffling gait Postural changes

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Parkinson’s Disease

Slow onset – several months to years Approximately 1 million Americans affected Usually develops between the ages of 45-69 Women and men equally affected Family history not a factor Progressive disease, if not treated causes

death Cause is not completely understood

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Parkinson’s Disease

Imbalance of dopamine and acetylcholine levels in the brain

Levels of other neurological chemical decrease:Gamma-aminobutyric acid (GABA)SerotoninNorepinephrine

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Classes of Anti-Parkinson Agents

Dopaminergic agentsCatechol-O-methyltransferase

inhibitorsCholinesterase inhibitorsAnticholinergic agents

Classes of Anti-Parkinson Agents

Non-ergot dopamine agonists (direct-acting dopamine receptor agonists) May be classified as “dopaminergic”

Indirect-acting dopamine receptor agonists (monoamine oxidase inhibitors, or MAOIs) Also can be classified as “dopaminergic”

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Dopaminergic agents

Levodopa prototype Most effective drug treatment Acts peripherally Rapidly converts to dopamine Symptoms subside or disappear

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Levodopa

Therapeutic effects Therapeutic intensity varies Dosage dependent

Adverse effects Nausea and vomiting Orthostatic hypotension Cardiac arrhythmias

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Carbidopa/Levodopa (Sinemet)

Carbidopa prevents levodopa from being broken down in the peripheral circulation

Improves neurological-skeletal muscle activity

Combining these agents reduces the required Levodopa dose by 25% Carbidopa, 10 mg / Levodopa,100

mg dose

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Amantadine (Symmetrel)

Anticholinergic/dopaminergic in action

Treats viral disorders such as influenza

Acts as an anti-Parkinson agent; it exerts an additive effect on LevodopaIncreases CNS dopamine

concentration

Other dopaminergic anti-PD drugs

Parlodel (bromocriptine mesylate) Ergot derivative; may allow reduced

maintenance levodopa dosage Mirapex (pramipexole dihydrochloride)

Nonergot; treats tremors, shaking, slow movements

Also treats restless leg syndrome Can cause hypotension – teach slow position

transition

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Other dopaminergic anti-PD drugs

Requip and RequipXL (ropinirole) Also treats RLS Lowers B/P

Neupro (rotigotine) patch Nonergot; treats early-stage PD Sleep attacks

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Other dopaminergic anti-PD drugs

Zelapar (selegiline HCl) Indirect-acting dopamine receptor agonist

/monoamine oxidase inhibitor

Patch developed for antidepressant (Emsam)

MAOIs – high risk of interaction with other medications Check for contraindications

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Newest class of anti-Parkinson drug agents

Treats clients with history of poor response to levodopaSustains dopaminergic levels

Brain remains stimulated

Catechol-O-Methyltransferase Inhibitors

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Catechol-O-Methyltransferase Inhibitors

Adverse effects Liver failure Dyskinesia Orthostatic hypotension Dystonia Somnolence GI irritation

Note interactions with other drugs

Catechol-O-Methyltransferase Inhibitors

Adjuncts to levodopa Comtan (entacapone)

Many interactions with other drugs Tasmar (tolcapone)

Liver damage

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Cholinesterase inhibitors

Exelon (rivastigmine) – origin as Alzheimer’s drug (see Ch. 28)

Apokyn (apomorphine HCl) SQ “rescue” drug for undermedicated, “frozen”

state. Four- to eight-minute onset give with antiemetic r/t morphine; not analgesic, no dependency

risk

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Anticholinergic Agents

Reduces excessive cholinergic brain activityExample: trihexyphenidyl (Artane)

Used for clients with minimal symptoms

Adjunct with other agents Caution: narrow-angle glaucoma

Anticholinergic Agents

Inhibit acetylcholine in PNS Cogentin (benztropine mesylate) Akineton (biperiden HCl) Kemadrin (procyclidine)

Adjunct agentsUse with minimal symptomsS

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Adverse Effects of Anticholinergics

Dry mouthUrinary retentionConstipation

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Nursing Considerations

Patients on levadopa (not Sinemet) should not take vitamin B6

Educate patient on disease process, medication therapy goals, and adverse effects and what to do about them

Assure adequate fluidsCounsel patients to be careful when

doing activities that require alertness

Nursing Considerations

Assess for need for other supportive therapies such as physical, occupational, and speech

High protein food may decrease absorption of levadopa

Assess patients self care abilities on an ongoing basis

Assess fall risk on an ongoing basis

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