Chapter 24 Antiparkinsonism Agents

Chapter 24  Antiparkinsonism Agents

Complete Chapter Questions And Answers
 

Sample Questions

1.
Degeneration in neurons that release a neurotransmitter leads to Parkinson’s disease. What neurotransmitter is involved?
A)
Gamma-aminobutyric acid (GABA)
B)
Acetylcholine
C)
Dopamine
D)
Serotonin
Ans:
C

Feedback:

Degeneration of dopamine-releasing neurons in the substantia nigra leads to Parkinson’s disease. When dopamine is decreased in the area of the corpus striatum, a chemical imbalance allows the cholinergic or excitatory cells to dominate. This affects the functioning of the basal ganglia and cortical and cerebellar components of the extrapyramidal motor system. This system provides coordination for unconscious muscle movements, including those that control position, posture, and movement. The result of the imbalance produces the signs and symptoms of Parkinson’s disease. The corpus striatum in the brain is connected to the substantia nigra by a series of neurons that use the inhibitory neurotransmitter GABA. Higher neurons from the cerebral cortex secrete acetylcholine in the area of the corpus striatum as an excitatory neurotransmitter to coordinate movements of the body. Serotonin is not involved in these functions.

2.
A 10-year-old boy has been prescribed an antiparkinsonian drug. Which drug would the nurse expect as the first choice for this child?
A)
Benztropine (Cogentin)
B)
Diphenhydramine (Benadryl)
C)
Trihexyphenidyl (Artane)
D)
Procyclidine (Kemadrin)
Ans:
B

Feedback:

Parkinson’s disease is rare in children. However, if a child needs an antiparkinsonian drug, diphenhydramine is the drug of choice. Benztropine, trihexyphenidyl, and procyclidine are not recommended for use in children.

3.
A patient is newly diagnosed with Parkinson’s disease. An anticholinergic drug is ordered for the patient. When reviewing the patient’s medical history, the nurse realizes an anticholinergic drug is contraindicated for this patient because of what secondary diagnosis? (Select all that apply.)
A)
Benign prostatic hypertrophy
B)
Narrow-angle glaucoma
C)
Myasthenia gravis
D)
Dysrhythmias
E)
Hepatic dysfunction
Ans:
A, B, C

Feedback:

Anticholinergics are contraindicated in the presence of narrow-angle glaucoma, GI obstruction, genitourinary (GU) obstruction, and prostatic hypertrophy, all of which could be exacerbated by the peripheral anticholinergic effects of these drugs, and in myasthenia gravis, which could be exacerbated by the blocking of acetylcholine-receptor sites at the neuromuscular synapses. These agents should be administered cautiously, but they are not contraindicated in therapy for the following conditions: tachycardia and other dysrhythmias and hypertension or hypotension because the blocking of the parasympathetic system may cause a dominance of sympathetic stimulatory activity, and in hepatic dysfunction, which could interfere with the metabolism of the drugs and lead to toxic levels.

4.
A patient is newly diagnosed with Parkinson’s disease and levodopa (Dopar) has been prescribed. What patient teaching information should be considered a high priority for this patient?
A)
Avoid vitamin B6 intake.
B)
Avoid hot environments.
C)
Many adverse effects will subside when the body adjusts to the drug.
D)
Allow rest periods.
Ans:
A

Feedback:

The priority information would be to avoid vitamin B6 intake, which would include grains and bran. Vitamin B6 speeds the conversion of levodopa to dopamine before it can cross the blood–brain barrier. This leads to Parkinson’s symptoms. The other options are all important and should be discussed with the patient. However, sweating, headaches, difficulty sleeping, fatigue, weakness, and dizziness are expected adverse effects, which will eventually subside or decrease.

5.
A patient with Parkinsonism has been told that the levodopa prescribed is no longer controlling the disease. What drug would the nurse question if ordered as adjunctive therapy?
A)
Diphenhydramine (Benadryl)
B)
Pramipexole (Mirapex)
C)
Trihexyphenidyl (Artane)
D)
Vitamin B6
Ans:
D

Feedback:

Vitamin B6 would further decrease the therapeutic effects of levodopa and is contraindicated with levodopa, so the nurse would question this order. Pramipexole, diphenhydramine, and trihexyphenidyl are all useful adjunctive drugs when Parkinson’s disease is no longer controlled with levodopa therapy alone.