Nokea
A patient is taking drug A and drug B. The primary care NP notes increased effects of drug B. The NP should suspect that in this case drug A is a cytochrome P450 (CYP450) enzyme:
- A. inhibitor.
- B. substrate.
- C. inducer.
- D. metabolizer.
Correct Answer: A
Rationale: The correct answer is A because a CYP450 inhibitor (drug A) reduces metabolism of drug B, increasing its effects. Choice B is incorrect as a substrate is acted upon, not inhibiting. Choice C is wrong since an inducer increases metabolism, reducing effects. Choice D is inaccurate as 'metabolizer' isn’t a CYP450 role.
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An example of a first-dose reaction that may occur includes:
- A. Orthostatic hypotension that does not occur with repeated doses
- B. Purple glove syndrome with phenytoin use
- C. Hemolytic anemia from ceftriaxone use
- D. Contact dermatitis from neomycin use
Correct Answer: A
Rationale: Choice A is correct because orthostatic hypotension can occur with a first dose of drugs like antihypertensives, subsiding as the body adjusts, a classic first-dose reaction. Choice B is incorrect as purple glove syndrome is a rare phenytoin effect, not first-dose specific. Choice C is wrong because hemolytic anemia is a type II reaction, not first-dose. Choice D is incorrect since contact dermatitis is a delayed, not first-dose, reaction.
Off-label use of drugs is:
- A. Illegal
- B. Regulated by the FDA
- C. Permitted with scientific evidence
- D. All of the above
Correct Answer: C
Rationale: Choice C is correct because off-label use is legal and common, permitted with scientific backing or clinical judgment, not FDA-regulated post-approval. Choice A is incorrect as it's not illegal. Choice B is wrong because FDA doesn't regulate off-label practice. Choice D is incorrect since only C applies.
A woman who is pregnant tells an NP that she has been taking sertraline for depression for several years but is worried about the effects of this drug on her fetus. The NP will consult with this patient's psychiatrist and will recommend that she:
- A. stop taking the sertraline now.
- B. continue taking the antidepressant.
- C. change to a different antidepressant.
- D. taper off the sertraline gradually.
Correct Answer: B
Rationale: The correct answer is B because continuing sertraline is often safer than untreated depression, with psychiatric consultation. Choice A is incorrect (abrupt stopping risky). Choice C is wrong (changing not first step). Choice D is inaccurate (tapering not indicated without specialist input).
The point in time on the drug concentration curve that indicates the first sign of a therapeutic effect is the:
- A. Minimum adverse effect level
- B. Peak of action
- C. Onset of action
- D. Therapeutic range
Correct Answer: C
Rationale: Choice C is correct because the onset of action is when a drug first shows a therapeutic effect on the concentration curve, marking the start of its clinical impact. Choice A is incorrect as ‘minimum adverse effect level' isn't a standard term; it confuses with toxicity thresholds. Choice B is wrong because peak of action is the maximum effect, not the first sign. Choice D is incorrect since therapeutic range is the concentration window for efficacy, not a specific time point.
Clinical judgment in prescribing includes:
- A. Factoring in the cost to the patient of the medication prescribed
- B. Always prescribing the newest medication available for the disease process
- C. Handing out drug samples to poor patients
- D. Prescribing all generic medications to cut costs
Correct Answer: S
Rationale: Choice A is correct because clinical judgment involves balancing efficacy, safety, and cost to ensure patients can afford and adhere to treatment, which is critical for successful outcomes. Choice B is incorrect as always choosing the newest medication ignores evidence-based practice; newer drugs may lack long-term data or be unnecessarily expensive. Choice C is wrong because distributing samples isn't a sustainable prescribing strategy and may not meet ongoing needs. Choice D is also incorrect since mandating generics could compromise efficacy if a brand-name drug is clinically necessary.