Seminar Three: Myasthenia Gravis Flashcards
A patient with myasthenia gravis is being educated about the disease. Which symptom should the nurse expect the patient to report?
A) Constipation
B) Drooping eyelids
C) Diarrhea
D) High blood pressure
Correct Answer:
B) Drooping eyelids
Rationale:
A common symptom of myasthenia gravis is ptosis (drooping eyelids) due to weakness of skeletal muscles. Other symptoms include difficulty swallowing and generalized muscle weakness.
A patient with myasthenia gravis is most likely to exhibit which of the following symptoms?
A) Hyperreflexia and tremors
B) Muscle weakness and ptosis
C) Sudden severe pain and muscle spasms
D) Sensory loss and numbness in extremities
Correct Answer:
B) Muscle weakness and ptosis
Rationale:
Myasthenia gravis is an autoimmune neuromuscular disorder characterized by muscle weakness and ptosis (drooping eyelids), especially after repeated use of muscles. It primarily affects voluntary muscles.
Which of the following best describes the mechanism of action of pyridostigmine in treating myasthenia gravis?
A) It inhibits acetylcholine release at the neuromuscular junction.
B) It blocks the action of acetylcholine at nicotinic receptors.
C) It enhances the breakdown of acetylcholine, reducing neurotransmitter levels.
D) It inhibits acetylcholinesterase, increasing acetylcholine availability at the neuromuscular junction.
Correct Answer:
D) It inhibits acetylcholinesterase, increasing acetylcholine availability at the neuromuscular junction.
Rationale:
Pyridostigmine works by inhibiting acetylcholinesterase, which breaks down acetylcholine. This increases acetylcholine availability, improving the communication between nerves and muscles, and thus improving muscle strength.
Which of the following adverse effects may occur due to the use of pyridostigmine?
A) Tachycardia, dry mouth, constipation
B) Excessive salivation, bradycardia, miosis
C) Hypertension, tachycardia, diarrhea
D) Muscle spasms, insomnia, tachypnea
Correct Answer:
B) Excessive salivation, bradycardia, miosis
Rationale:
Pyridostigmine increases the availability of acetylcholine, leading to excessive muscarinic activity such as excessive salivation, bradycardia, and miosis (pupil constriction).
Which medication can be administered to counteract the adverse effects of pyridostigmine?
A) Epinephrine
B) Atropine
C) Propranolol
D) Acetylcysteine
Correct Answer:
B) Atropine
Rationale:
Atropine is an anticholinergic drug that can be used to reverse the muscarinic effects of pyridostigmine, such as excessive salivation and bradycardia.
What is the difference between reversible and irreversible cholinergic inhibitors?
A) Reversible inhibitors bind permanently, while irreversible inhibitors are temporary.
B) Irreversible inhibitors are primarily used therapeutically for hypertension.
C) Reversible inhibitors bind temporarily and are safer for therapeutic use, while irreversible inhibitors are highly toxic and are used in insecticides.
D) Reversible inhibitors are lipid-soluble and highly toxic, while irreversible inhibitors are water-soluble.
Correct Answer:
C) Reversible inhibitors bind temporarily and are safer for therapeutic use, while irreversible inhibitors are highly toxic and are used in insecticides.
Rationale:
Reversible cholinergic inhibitors are used in therapeutic settings as their effects are temporary. Irreversible inhibitors are highly toxic and used as insecticides due to their long-lasting effects and ease of absorption.
When Jane asks why her dose of pyridostigmine is low, which of the following would be the nurse’s best response?
A) “The low dose is used because higher doses can cause severe respiratory depression.”
B) “The low dose is intended to minimize potential side effects, and it may be gradually increased depending on your response and side effects.”
C) “This dose is low because you are newly diagnosed, and patients with new diagnoses cannot tolerate higher doses.”
D) “The neurologist prescribed a low dose because it will prevent the need for follow-up visits.”
Correct Answer:
B) “The low dose is intended to minimize potential side effects, and it may be gradually increased depending on your response and side effects.”
Rationale:
Dosing of pyridostigmine is often started low to minimize side effects and is adjusted based on the patient’s response to treatment and tolerance to side effects.
Jane asks how she will know if her pyridostigmine is working. The nurse should respond by stating which of the following?
A) “You will notice a significant decrease in blood pressure and heart rate.”
B) “Your muscles will feel stronger, and symptoms like fatigue and eye drooping should improve.”
C) “You may notice an increase in saliva production and sweating.”
D) “Your appetite will improve, and you may gain weight.”
Correct Answer:
B) “Your muscles will feel stronger, and symptoms like fatigue and eye drooping should improve.”
Rationale:
Pyridostigmine improves muscle strength in patients with myasthenia gravis, leading to a reduction in symptoms such as fatigue and ptosis (drooping eyelids).
What should the nurse instruct Jane to do if she misses a dose of pyridostigmine?
A) Take two doses together at the next scheduled time.
B) Skip the missed dose and resume her regular schedule.
C) Take the missed dose as soon as she remembers unless it’s close to the next dose.
D) Stop taking the medication until she can speak to her doctor.
Correct Answer:
C) Take the missed dose as soon as she remembers unless it’s close to the next dose.
Rationale:
Patients should be instructed to take the missed dose as soon as possible unless it is close to the time of the next dose. Doubling up on doses is not advised.
The nurse is teaching Jane about cholinergic crisis. Which of the following symptoms should the nurse include as signs of cholinergic crisis?
A) Tachycardia, dry skin, blurred vision
B) Sweating, bradycardia, excessive salivation
C) Hypertension, muscle twitching, dry mouth
D) Nausea, tremors, high blood pressure
Correct Answer:
B) Sweating, bradycardia, excessive salivation
Rationale:
A cholinergic crisis involves excessive muscarinic stimulation, leading to symptoms such as sweating, bradycardia, and excessive salivation. These symptoms can be remembered with mnemonics like SLUDGE and DUMBELS.
How does pyridostigmine help treat myasthenia gravis?
A) By breaking down acetylcholine at the neuromuscular junction.
B) By inhibiting acetylcholinesterase, increasing acetylcholine levels.
C) By decreasing the amount of acetylcholine available in the body.
D) By blocking nicotinic receptors at the neuromuscular junction.
Correct Answer:
B) By inhibiting acetylcholinesterase, increasing acetylcholine levels.
Rationale:
Pyridostigmine inhibits acetylcholinesterase, the enzyme responsible for breaking down acetylcholine. This leads to increased acetylcholine availability at the neuromuscular junction, improving muscle strength.
What is a common adverse effect of pyridostigmine?
A) Constipation
B) Increased heart rate
C) Excessive salivation
D) Dry skin
Correct Answer:
C) Excessive salivation
Rationale:
Pyridostigmine can cause adverse effects due to increased muscarinic stimulation, including excessive salivation, urinary urgency, and bradycardia.
What medication can help manage the adverse effects of pyridostigmine?
A) Atropine
B) Epinephrine
C) Acetaminophen
D) Metoprolol
Correct Answer:
A) Atropine
Rationale:
Atropine is an anticholinergic drug that can be used to manage adverse effects such as excessive salivation and bradycardia caused by pyridostigmine.
