Nokea
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.
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A patient who has HIV has been receiving a two-drug combination therapy for 6 months. At an annual physical examination, the primary care NP notes that the patient has a viral load of 60 copies/mL and a CD4 cell count of 350 cells/mm. The NP should contact the patient's infectious disease specialist to discuss:
- A. changing one of the medications.
- B. increasing the dose of both medications.
- C. discontinuing the medications for a short period.
- D. adding a third medication.
Correct Answer: B
Rationale: The correct answer is B because a high viral load and low CD4 suggest poor control, often needing dose adjustment. Choice A is incorrect (both should change if switching). Choice C is wrong (discontinuing risky). Choice D is inaccurate (text-based, not an option).
Drugs that are affected by genetic polymorphisms of UGT1A1 include:
- A. Warfarin
- B. Irinotecan
- C. Acetaminophen
- D. All of the above
Correct Answer: B
Rationale: Choice B is correct because irinotecan's active metabolite is glucuronidated by UGT1A1; poor function increases toxicity, requiring genetic consideration. Choice A is incorrect as warfarin's metabolism is via CYP2C9, not UGT1A1. Choice C is wrong because acetaminophen uses other UGT enzymes, not specifically UGT1A1 critically. Choice D is incorrect since only irinotecan is notably affected by UGT1A1 polymorphisms.
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).
A 4-month-old infant has a viral illness with high fever and cough. The infant's parent asks the NP about what to give the infant to help with symptoms. The NP should prescribe which of the following?
- A. Aspirin to treat the fever
- B. Acetaminophen as needed
- C. Dextromethorphan for coughing
- D. An antibiotic to prevent increased infection
Correct Answer: B
Rationale: The correct answer is B because acetaminophen is safe for infants to reduce fever. Choice A is incorrect (aspirin risks Reye’s syndrome). Choice C is wrong (dextromethorphan risks respiratory depression). Choice D is inaccurate (antibiotics don’t treat viral illness).
Risks associated with polypharmacy include:
- A. Increased adverse drug reactions
- B. Drug-drug interactions
- C. Nonadherence
- D. All of the above
Correct Answer: D
Rationale: Choice D is correct because polypharmacy raises ADR risk (more drugs, more side effects), interactions (competing metabolism), and nonadherence (complex regimens), per geriatric studies. Choice A is incorrect alone as it's one risk. Choice B is wrong by itself because interactions are just part. Choice C is incorrect solo since nonadherence is only one issue.