Nokea
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.
You may also like to solve these questions
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.
Pharmacokinetic changes in the elderly that affect drug dosing include:
- A. Decreased renal function
- B. Increased liver metabolism
- C. Decreased body fat
- D. All of the above
Correct Answer: A
Rationale: Choice A is correct because decreased renal function in the elderly slows drug excretion, requiring dose adjustments to prevent accumulation, per geriatric pharmacology. Choice B is incorrect as liver metabolism decreases, not increases. Choice C is wrong because body fat increases, not decreases. Choice D is incorrect since only A is accurate.
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.
Herbal products that may increase INR include:
- A. Ginkgo biloba
- B. St John's wort
- C. Valerian root
- D. All of the above
Correct Answer: A
Rationale: Choice A is correct because ginkgo biloba can increase INR by enhancing warfarin's effect through antiplatelet activity, risking bleeding. Choice B is incorrect as St John's wort induces CYP2C9, decreasing INR and warfarin efficacy. Choice C is wrong because valerian root doesn't significantly alter INR. Choice D is incorrect since only ginkgo biloba increases INR.
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.