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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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.
An agonist activates a receptor and stimulates a response. When given frequently over time, the body may:
- A. Upregulate the total number of receptors
- B. Block the receptor with a partial agonist
- C. Alter the drug's metabolism
- D. Downregulate the numbers of that specific receptor
Correct Answer: D
Rationale: Choice D is correct because frequent agonist use can cause the body to downregulate receptors, reducing sensitivity to overstimulation as a compensatory mechanism. Choice A is incorrect as upregulation occurs with antagonists, not agonists. Choice B is wrong because partial agonists compete, not result from frequent use. Choice C is incorrect since metabolism changes aren't the primary receptor response.
An 80-year-old patient who has COPD takes TMP/SMX for acute exacerbations, which occur three or four times each year. To monitor this patient for adverse drug reactions, the primary care NP should order:
- A. liver function tests.
- B. blood urea nitrogen and creatinine.
- C. serum bilirubin levels.
- D. a complete blood count (CBC) with differential.
Correct Answer: D
Rationale: The correct answer is D because elderly patients on TMP/SMX risk bone marrow suppression, monitored via CBC. Choice A is incorrect (liver tests pre-treatment). Choice B is wrong (renal pre-treatment). Choice C is inaccurate (bilirubin not primary).
Upregulation or hypersensitization may lead to:
- A. Increased response to a drug
- B. Decreased response to a drug
- C. An exaggerated response if the drug is withdrawn
- D. Refractoriness or complete lack of response
Correct Answer: C
Rationale: Choice C is correct because upregulation (more receptors) or hypersensitization from chronic antagonist use can cause an exaggerated rebound response if withdrawn, as seen with beta blockers. Choice A is incorrect as increased response occurs during use, not withdrawal. Choice B is wrong because decreased response isn't typical of upregulation. Choice D is incorrect since refractoriness relates to agonists, not this scenario.
Passive monitoring of drug effectiveness includes:
- A. Therapeutic drug levels
- B. Adding or subtracting medications from the treatment regimen
- C. Ongoing provider visits
- D. Instructing the patient to report if the drug is not effective
Correct Answer: D
Rationale: Choice D is correct because passive monitoring relies on patient feedback, like reporting ineffectiveness, rather than active measures like lab tests. Choice A is incorrect as therapeutic levels are active monitoring. Choice B is wrong because adjusting medications is an intervention, not monitoring. Choice C is incorrect since provider visits are active engagement, not passive.