ATI RN
Chapter 2 pharmacologic principles Questions
Question 1 of 5
A 59-year-old female with diabetes presents to her primary care physician for routine follow-up. Her current medications include insulin. Her fasting blood sugars are in the range of 80 to $120 \mathrm{mg} / \mathrm{dL}$. The intracellular effects of this medication are likely caused by which of the following mechanisms of action?
Correct Answer: C
Rationale: Insulin's intracellular effects occur via protein phosphorylation (C). Binding its tyrosine kinase receptor, insulin triggers autophosphorylation, activating cascades (e.g., PI3K-Akt) that phosphorylate proteins, promoting glucose uptake (GLUT4 translocation). Ionic changes (A) and membrane potential (B) are ion channel effects. Protein and receptor phosphorylation (D) overcomplicates; receptor phosphorylation initiates, but cellular effects are downstream. Receptor destruction (original E) is false. This mechanism ensures glycemic control (80-120 mg/dL), critical in diabetes management, distinguishing insulin from ionotropic drugs.
Question 2 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 3 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 4 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.
Question 5 of 5
The pharmacokinetic 'elimination half-life' of the following drugs mirrors their pharmacodynamic duration and intensity of action:
Correct Answer: C
Rationale: Dobutamine (C) has a half-life (~2 min) mirroring its short-lived inotropic effect, used in acute heart failure. Salbutamol (A) has a longer duration (~4-6 h) than its half-life (~4 h). Phenelzine (B) is an irreversible MAOI, with effects outlasting its half-life. Omeprazole (D) inhibits pumps long-term despite a short half-life. Cyclophosphamide (original E) has prolonged effects via metabolites. Dobutamine's tight pharmacokinetic-pharmacodynamic link ensures rapid titration, critical in ICU settings, unlike drugs with dissociated durations.