Why is levodopa, rather than dopamine itself, given to replace dopamine in Parkinson's disease?
Dopamine cannot cross the blood-brain barrier
✓
Dopamine binds only to muscarinic receptors
Dopamine is a Schedule II controlled substance
Dopamine causes severe bronchospasm
Correct Answer
Dopamine cannot cross the blood-brain barrier
Dopamine given by mouth or IV stays outside the brain because it cannot cross the blood-brain barrier, while its precursor levodopa can and is converted to dopamine inside the brain. Dopamine binds only to muscarinic receptors is wrong because dopamine acts on dopamine receptors. Dopamine is a Schedule II controlled substance is false; it is not scheduled. Dopamine causes severe bronchospasm is not true and is not the reason it is avoided.
Category: Levodopa Therapy
Question 2
How does carbidopa make levodopa more effective?
It stimulates dopamine receptors in the striatum
It blocks peripheral conversion of levodopa to dopamine
✓
It slows breakdown of dopamine by MAO-B in the brain
It blocks muscarinic receptors in the basal ganglia
Correct Answer
It blocks peripheral conversion of levodopa to dopamine
Carbidopa inhibits the decarboxylase enzyme outside the brain, so more levodopa reaches the brain and peripheral effects such as nausea decrease; carbidopa itself does not cross the blood-brain barrier. It stimulates dopamine receptors in the striatum describes a dopamine agonist. It slows breakdown of dopamine by MAO-B in the brain describes selegiline or rasagiline. It blocks muscarinic receptors in the basal ganglia describes anticholinergics such as benztropine.
Category: Levodopa Therapy
Question 3
A patient taking carbidopa/levodopa is worried because their urine and sweat have turned dark brown. What should the nurse tell the patient?
Stop the drug at once and go to the emergency department
A urine culture is needed to rule out infection
This harmless color change is an expected drug effect
✓
The color change means the dose is too high
Correct Answer
This harmless color change is an expected drug effect
Levodopa metabolites can darken urine and sweat to a brownish color; it is harmless, and the patient should keep taking the drug. Stop the drug at once and go to the emergency department is wrong, and abrupt stopping can itself be dangerous. A urine culture is needed to rule out infection is unnecessary for this known effect. The color change means the dose is too high is false; it does not reflect dose.
Category: Levodopa Therapy
Question 4
Giving levodopa to a patient who is taking a nonselective MAO inhibitor such as phenelzine creates a risk of which reaction?
Severe hypoglycemia
Agranulocytosis
Hyperkalemia
Hypertensive crisis
✓
Correct Answer
Hypertensive crisis
A nonselective MAO inhibitor prevents breakdown of the dopamine and norepinephrine made from levodopa, which can cause a hypertensive crisis; the MAO inhibitor is stopped at least 2 weeks before levodopa is started. Severe hypoglycemia is not a recognized result of this combination. Agranulocytosis is a blood disorder not tied to this interaction. Hyperkalemia is not caused by either drug.
Category: Levodopa Therapy
Question 5
A patient on long-term levodopa describes sudden, unpredictable swings from moving well to being almost unable to move, unrelated to when the dose was taken. What is this called?
On-off phenomenon
✓
Wearing-off effect
Tardive dyskinesia
Akathisia
Correct Answer
On-off phenomenon
The on-off phenomenon is an abrupt, unpredictable loss of drug effect that develops with long-term levodopa therapy. Wearing-off effect is a gradual, predictable return of symptoms near the end of a dosing interval. Tardive dyskinesia is a movement disorder caused mainly by long-term antipsychotic use. Akathisia is a feeling of inner restlessness, not sudden immobility.
Category: Levodopa Therapy
Question 6
The spouse of a patient who recently started pramipexole reports that the patient has begun gambling heavily and spending large sums online. How should the nurse interpret this?
An expected sign that the disease is progressing
A drug adverse effect that should be reported
✓
A sign of tolerance to the drug's effects
A withdrawal reaction from a missed dose
Correct Answer
A drug adverse effect that should be reported
Dopamine agonists such as pramipexole can cause impulse control problems such as compulsive gambling, shopping and hypersexuality; the effect is dose related and usually reverses when the drug is reduced or stopped, so it must be reported. An expected sign that the disease is progressing is wrong because the behavior comes from the drug. A sign of tolerance to the drug's effects does not explain new compulsive behavior. A withdrawal reaction from a missed dose does not cause gambling.
Category: Dopamine Agonists
Question 7
For what purpose is apomorphine used in advanced Parkinson's disease?
Prevention of nausea caused by levodopa
Slowing the loss of dopamine neurons
Rescue treatment of sudden off episodes
✓
Treatment of drug-induced dystonia
Correct Answer
Rescue treatment of sudden off episodes
Apomorphine is a short-acting dopamine agonist given by subcutaneous injection or under the tongue to quickly reverse off episodes. Prevention of nausea caused by levodopa is wrong; apomorphine itself is strongly emetogenic. Slowing the loss of dopamine neurons is not something apomorphine does. Treatment of drug-induced dystonia is a use of anticholinergics such as benztropine.
Category: Dopamine Agonists
Question 8
Which dopamine agonist is an ergot derivative?
Pramipexole
Ropinirole
Rotigotine
Bromocriptine
✓
Correct Answer
Bromocriptine
Bromocriptine is an ergot derivative that also acts on serotonin and alpha-adrenergic receptors, which adds cardiovascular effects. Pramipexole is a nonergot dopamine agonist. Ropinirole is also nonergot. Rotigotine is a nonergot agonist given as a transdermal patch.
Category: Dopamine Agonists
Question 9
A patient taking rasagiline is prescribed meperidine for pain. The nurse questions the order because the combination can cause which reaction?
Serotonin syndrome
✓
Malignant hyperthermia
Lactic acidosis
Aplastic anemia
Correct Answer
Serotonin syndrome
MAO-B inhibitors such as rasagiline and selegiline combined with meperidine, tramadol or SSRIs can cause serotonin syndrome, with agitation, fever, tremor and autonomic instability. Malignant hyperthermia is triggered by certain anesthetics and succinylcholine. Lactic acidosis is a concern with metformin. Aplastic anemia is not an effect of this combination.
Category: MAO-B and COMT Inhibitors
Question 10
Entacapone is added to carbidopa/levodopa mainly to achieve which goal?
Relieve levodopa-induced nausea
Reduce end-of-dose wearing-off
✓
Treat drug-induced psychosis
Replace levodopa in early disease
Correct Answer
Reduce end-of-dose wearing-off
Entacapone blocks COMT, which breaks down levodopa outside the brain, so each levodopa dose lasts longer and wearing-off is reduced. Relieve levodopa-induced nausea is the role of carbidopa. Treat drug-induced psychosis is wrong; COMT inhibitors can actually cause hallucinations. Replace levodopa in early disease is impossible because entacapone has no effect without levodopa.
Category: MAO-B and COMT Inhibitors
Question 11
A patient taking carbidopa/levodopa also takes ferrous sulfate for anemia. How does the iron affect levodopa therapy?
It raises the blood level of levodopa
It blocks the action of carbidopa
It reduces the absorption of levodopa
✓
It causes severe hypokalemia
Correct Answer
It reduces the absorption of levodopa
Iron salts bind levodopa in the gut and reduce its absorption, so the two are separated and patients avoid taking iron-containing supplements with their dose. It raises the blood level of levodopa is the opposite of the real effect. It blocks the action of carbidopa is not the mechanism. It causes severe hypokalemia is not an effect of iron or levodopa.
Category: Levodopa Therapy
Question 12
A patient taking trihexyphenidyl is also prescribed amitriptyline. The nurse monitors for which problem?
Additive bleeding risk
Loss of the antidepressant effect
Severe hypoglycemia
Additive anticholinergic effects
✓
Correct Answer
Additive anticholinergic effects
Tricyclic antidepressants such as amitriptyline have strong anticholinergic effects that add to those of trihexyphenidyl, raising the risk of confusion, urinary retention, constipation, dry mouth and blurred vision. Additive bleeding risk is not a feature of either drug. Loss of the antidepressant effect does not occur from this combination. Severe hypoglycemia is not a recognized interaction here.
Category: Anticholinergics
Question 13
In Parkinson's disease, loss of dopamine leaves which neurotransmitter relatively in excess in the basal ganglia?
Acetylcholine
✓
Serotonin
Histamine
Norepinephrine
Correct Answer
Acetylcholine
Dopamine normally restrains the excitatory effects of acetylcholine in the basal ganglia, so when dopamine falls, acetylcholine dominates; this is why anticholinergic drugs help some symptoms. Serotonin is not the neurotransmitter left in excess. Histamine is not the basis of this imbalance. Norepinephrine is not left in excess; noradrenergic neurons of the locus coeruleus also degenerate in Parkinson's disease.
Category: Parkinson's Basics
Question 14
A patient starting interferon beta-1a asks how to lessen the flu-like symptoms that often follow each injection. What should the nurse suggest?
Take each dose with a high-fat meal
Take an analgesic-antipyretic before each injection
✓
Skip a dose whenever symptoms occur
Lie flat for an hour after each injection
Correct Answer
Take an analgesic-antipyretic before each injection
Flu-like symptoms are the most familiar effect of interferon beta, and taking acetaminophen or an NSAID before the injection, often with bedtime dosing, reduces them. Take each dose with a high-fat meal has no effect on an injected drug. Skip a dose whenever symptoms occur undermines disease control. Lie flat for an hour after each injection does nothing to prevent the flu-like reaction.
Category: MS Disease-Modifying Drugs
Question 15
Natalizumab carries a boxed warning for which serious adverse effect?
Severe hemorrhagic cystitis
Progressive pulmonary fibrosis
Progressive multifocal leukoencephalopathy
✓
Irreversible ototoxicity
Correct Answer
Progressive multifocal leukoencephalopathy
Natalizumab blocks immune cells from entering the central nervous system, which raises the risk of progressive multifocal leukoencephalopathy, a potentially fatal brain infection by the JC virus; it is given only through a restricted program. Severe hemorrhagic cystitis is linked to cyclophosphamide and ifosfamide. Progressive pulmonary fibrosis is linked to drugs such as bleomycin and amiodarone. Irreversible ototoxicity is linked to drugs such as aminoglycosides.
Category: MS Disease-Modifying Drugs
Question 16
Because monomethyl fumarate can lower the lymphocyte count, which test does the nurse expect before therapy and periodically during it?
Serum uric acid level
Pulmonary function testing
Serum amylase level
Complete blood count with differential
✓
Correct Answer
Complete blood count with differential
Fumarate drugs for multiple sclerosis can cause lymphopenia, which raises the risk of serious infections such as progressive multifocal leukoencephalopathy, so a complete blood count with differential is drawn at baseline and repeated during therapy. Serum uric acid level is not affected by this drug. Pulmonary function testing is not part of fumarate monitoring. Serum amylase level does not track the lymphocyte effect.
Category: MS Disease-Modifying Drugs
Question 17
A few minutes after injecting glatiramer, a patient has flushing, chest tightness and palpitations that resolve on their own within 15 minutes. How should the nurse interpret this?
A known postinjection reaction that is usually brief
✓
A sign of an acute myocardial infarction
Evidence that the drug was injected into a vein
A sign that the dose was too high
Correct Answer
A known postinjection reaction that is usually brief
Glatiramer can cause a postinjection reaction of flushing, chest tightness, palpitations and dyspnea that usually resolves within minutes; a longer or more intense reaction needs prompt reporting. A sign of an acute myocardial infarction would not resolve completely in minutes. Evidence that the drug was injected into a vein is not the explanation for this known reaction. A sign that the dose was too high is wrong because it occurs at standard doses.
Category: MS Disease-Modifying Drugs
Question 18
After the first dose of the S1P receptor modulator siponimod, the nurse monitors the patient closely for which effect?
Tachycardia
Bradycardia
✓
Hyperglycemia
Hypokalemia
Correct Answer
Bradycardia
S1P receptor modulators can slow the heart rate and cause AV block when therapy starts, so a baseline ECG is obtained, the dose is increased gradually, and patients with certain heart conditions are monitored closely after the first dose. Tachycardia is the opposite of the expected first-dose effect. Hyperglycemia is not a first-dose concern. Hypokalemia is not caused by siponimod.
Category: MS Disease-Modifying Drugs
Question 19
A patient with an intrathecal baclofen pump misses a scheduled refill and develops high fever, confusion and severe rebound muscle stiffness. What does the nurse suspect?
Baclofen overdose
Autonomic dysreflexia
Baclofen withdrawal
✓
Bacterial meningitis
Correct Answer
Baclofen withdrawal
Abrupt interruption of baclofen, especially intrathecal delivery, can cause high fever, altered mental status, rebound spasticity and rigidity that can progress to rhabdomyolysis and death; it carries a boxed warning. Baclofen overdose causes drowsiness, weakness and respiratory depression instead. Autonomic dysreflexia is a spinal cord injury emergency marked by severe hypertension and bradycardia, not fever and rigidity. Bacterial meningitis can cause fever and confusion but does not explain the timing with a missed refill and rebound spasticity.
Category: MS Symptom Drugs
Question 20
Ocrelizumab, a monoclonal antibody used for multiple sclerosis, works by depleting which cells?
Natural killer cells
Mast cells
Eosinophils
B lymphocytes
✓
Correct Answer
B lymphocytes
Ocrelizumab binds CD20 on B lymphocytes and depletes them, reducing the immune attack on myelin. Natural killer cells are not its target. Mast cells are not depleted by ocrelizumab. Eosinophils are not its target either.
Category: MS Disease-Modifying Drugs