ATI RN
Chapter 2 pharmacologic principles Questions
Question 1 of 5
A hospitalized patient with systemic candidiasis is receiving intravenous antifungal medications. He also has hepatic and renal insufficiency. Which of the following drug administration schemes would allow for the most steady state amount of drug in the body over a 2-week hospitalization period where medication administration will be necessary?
Correct Answer: A
Rationale: Continuous IV infusion (A) provides the most steady-state drug levels over 2 weeks in a patient with systemic candidiasis and hepatic/renal insufficiency. It delivers a constant rate, compensating for impaired clearance (e.g., antifungals like amphotericin), avoiding peaks/troughs of intermittent dosing (B, C, D, E original). Weekly (B) or twice-weekly (E) injections risk subtherapeutic gaps; daily (C) or twice-daily (D) cause fluctuations. Steady-state maintenance is critical in severe infections with compromised metabolism/excretion, ensuring consistent therapeutic levels, reducing toxicity, and optimizing outcomes in critical care.
Question 2 of 5
A 61-year-old man is taking over-the-counter pseudoephedrine for cold and flulike symptoms. Over the course of the next few days, he experiences improvement in his rhinitis but should be concerned about the possibility of which of the following problems?
Correct Answer: D
Rationale: Urinary retention (D) is a concern with pseudoephedrine, an $\alpha_1$-agonist causing urethral sphincter contraction, impairing bladder emptying, especially in older men (e.g., with BPH). Iris contraction (A) is muscarinic, not adrenergic. Bronchoconstriction (B) contradicts its $\beta_2$-mediated dilation. Erectile improvement (C) isn't typical; $\alpha$-effects may worsen it. Thinning secretions (original E) occurs but isn't problematic. This $\alpha$-adrenergic side effect, critical in the elderly, requires caution, balancing rhinitis relief with urinary risks.
Question 3 of 5
A 34-year-old female insists on drinking a cup of grapefruit juice every morning for 'body cleansing.' Grapefruit juice is known to interfere with the cytochrome P450 system, disrupting levels of certain drugs. The cytochrome P450 system includes dozens of enzymes. Which is the most abundant CYP enzyme in human livers?
Correct Answer: E
Rationale: CYP3A4 (E, original) is the most abundant CYP enzyme in human livers (~30-40\% of total), metabolizing many drugs (e.g., statins). Grapefruit juice inhibits it, raising drug levels (e.g., felodipine). CYP1A2 (A) handles caffeine, CYP2A6 (B) nicotine, CYP2D6 (C) antidepressants, and CYP2E1 (D) ethanol:all less abundant. CYP3A4's dominance and intestinal presence amplify juice interactions, critical in pharmacokinetics, necessitating caution with co-administered substrates.
Question 4 of 5
An 18-year-old college student is hanging shelves in his dorm room. He accidently hits his thumb with the hammer, which subsequently becomes swollen and red. He takes some acetaminophen for the pain. Many proteins are activated in response to injury leading to inflammation. Which of the following proteins is a transcription factor?
Correct Answer: D
Rationale: NF-κB (D) is a transcription factor, activated in inflammation (e.g., thumb injury), translocating to the nucleus to upregulate genes (e.g., cytokines) driving swelling/redness. COX-2 (A) is an enzyme (prostaglandin synthesis). HAT (B) is a histone acetyltransferase, not a direct factor. IκB (C) inhibits NF-κB. iNOS (original E) produces nitric oxide. NF-κB's role amplifies inflammation, indirectly reduced by acetaminophen's COX inhibition, a key molecular link in pain/inflammatory pathways.
Question 5 of 5
A 59-year-old man with decreased urinary stream and hypertension is prescribed doxazosin in hopes that both problems will be treated. He begins dose escalation with $1 \mathrm{mg}$ given for one week, $2 \mathrm{mg}$ given for 2 weeks, and $4 \mathrm{mg}$ given for maintenance. He returns to his primary care physician saying that this medication is not helping. To determine whether or not the patient is taking the medication, it would be useful to look at the excreted concentration of medication in which of the following areas?
Correct Answer: D
Rationale: Urine (D) is useful to measure doxazosin's excreted concentration, as this $\alpha_1$-blocker is renally cleared, reflecting compliance (e.g., via metabolites). Blood (A) shows active levels, not excretion. Feces (B) is minor for doxazosin. Liver extract (C) is invasive, impractical. Skin (original E) is irrelevant. Urine testing confirms intake, critical in assessing BPH/hypertension treatment failure, distinguishing non-compliance from resistance, a practical pharmacokinetic approach.