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Parkinson’s Disease

Mary Jo Cameron

Pharmocology

Dr. K

4/15/2014

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Parkinson’s disease is a chronic neurodegenerative disorder that affects the dopamine

producing neurons in the brain. Parkinson’s was first discovered in 1817 and was once known as

shaking palsy. This name was made up because researchers did not know the underlying cause

until the 1960’s. One hundred and forty three years later, the disease was named after James

Parkinson. Over a century later, they figured out the real reason for this disease. Parkinson’s is

caused by having deficit amounts of dopamine in the cerebral cortex. The cerebral cortex

controls motor function such as posture, muscle tone, and smooth muscle.

In the brain, there are two neurotransmitters released, dopamine and acetylcholine, that need

to be balanced to regulate voluntary movements. Dopamine inhibits while acetylcholine excites

so these movements can occur. This imbalance happens in the basal ganglia. This imbalance

leads to the failure of nerve terminals in the substantia nigra. Since there is a scarce amount of

dopamine, the substantia nigra slowly degenerates and becomes damaged leading to dopamine

depletion. In return, the acetylcholine is at high levels because there is no dopamine to

counterpart the neurotransmitter. Parkinson’s is a dopamine deficit disease that is still evolving

as we research more.

Parkinson’s disease does not have a known cause but there are many theories some

researchers have come up with. Some think that past head injury, excess iron in the substantia

nigra, or premature aging can cause low dopamine levels. Parkinson’s affects one million

Americans and is the second most common neurodegenerative disease leading after Alzheimer’s

disease. P.D. is seen apparent in the 45-65 years young age group, averaging at 56 years old.

Though this disease is idiopathic, there is a two percent chance of getting it in our life time. It

has been noticed men are more affected than woman with a 3:2 ratio. Lastly, researchers are

trying to figure out if there is any genetic relation to how this disease progresses.

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Since there is no readily available cause of Parkinson’s, it becomes harder to detect if it is

affecting a patient. Usually health care providers look for signs of bradykinesia, postural

instability, rigidity, and tremors through a physical examination known as TRAP. Researchers

have experimented with CT, MRI, and EEG scans for better detection but without tests coming

back normal, we have to focus of physical symptoms. Treatment comes as more palliative care

by prolonging to use of the patients physical body. The body may not react this way until the

dopamine level is 80% depleted. Many go through physical, speech, and occupational therapy

which decreases the progression of Parkinson’s disease. Though we can provide therapy,

Parkinson’s disease associated dementia is closely correlated.

There are six major Parkinson’s drugs that were highlighted in the text. These six

medications are given together to better prevent further depletion, faster. The six drug categories

are MAO-B Inhibitor, dopamine modulator, COMT inhibitor, Ergot derivative, Nonergot, and

dopamine replacement. As this paper goes more into detail about the indications, side effects,

contraindications and protocols of each medication highlighted.

The main MAO-B inhibitor was selegiline (Emsam). This medication manages the signs and

symptoms of Parkinson’s disease. The side effects are the basic headache, diarrhea, dry mouth,

and weight gain or loss. Contradictions can happen if the patient is hypersensitive to the drug,

and patients taking MAO inhibitors, methadone, and SSRIs, etc. The protocol for selegiline is

starting the patient off at a lower dose two times a day but may need to lower the levodopa

dosage to make the medication steady.

The main dopamine modulator is the drug amantadine. This drug is used as a monotherapy

for Parkinson’s patients. The side effects are dizziness, irritability, depression, fatigue and many

more. Contradictions can be seen in elderly patients and ones that suffer with heart failure,

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mental illness, etc. The protocol for amantadine is very confusing based on the CrCl which will

determine which dosage the patient receives.

The most popular COMT inhibitor is known as entacapone (Comtan). This drug is used in

Parkinson’s patients where they are taking levodopa but have signs and symptoms of “end of

dose wearing off”. Side effects include dizziness, anxiety, urine discoloration, and sweating.

Contradictions with entacapone include patients with hepatic impairment or orthostatic

hypotension. Lastly, the protocol on this specific medication is to give 200 mg with each dose of

levodopa, up to eight times a day.

The ergot derivative used in the health care field more often is bromocriptine (Parlodel). This

medication helps with dopamine receptor agonists. The side effects are nasal congestion, light-

headedness, and delusions. Contradictions found to happen are found in those common with

uncontrolled hypertension, lactase deficiency, and peripheral vascular disease. The main

protocol for this medication is to be given twice a day at 1.25 mg with meals.

The nonergot given to Parkinson’s patients is ropinirole (Requip). Side effects associated

with this medication include fatigue, flushing, vomiting, or impotence. Contradictions can also

occur in patients with severe hepatic or renal impairment. Lastly, the main protocol for this drug

is to give 0.25 mg in the beginning and slowly increase the medication so the body can adapt.

Lastly, the most known dopamine replacement drug is known as levodopa (Parcopa),

mentioned in earlier explanations. The reason for this drug is for carbon monoxide or manganese

intoxication due to the Parkinson’s disease and also converts dopamine in the brain. The side

effects can be anything from suicidal ideations, hypotension, confusion, etc. The contradictions

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include taking a MAO inhibitor within 14 days of this medication. The protocol for levodopa is

100mg tablets with a mix of bidopa and carbidopa tablets.

Parkinson’s disease has an unknown cause but many medications to help with the

contradictions of the disease. After learning about how Parkinson’s was researched, the drugs

above show the different ways a patient can go in regards to dealing with their disease. As it

worsens, physical, speech, and occupational therapy will help keep the patient active. The six

drugs listed in the categories of MAO-B Inhibitor, dopamine modulator, COMT inhibitor, Ergot

derivative, Nonergot, and dopamine replacement, are Anti-Parkinson’s drugs here to help every

patient out.

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WORKS CITED

Lilley, Linda Lane., Shelly Rainforth. Collins, Julie S. Snyder, and Diane Savoca. Pharmacology and the Nursing Process. St. Louis, MO: Elsevier/Mosby, 2014. Print.

Nursing 2014 Drug Handbook. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, 2014. Print.