ATI RN
Chapter 2 pharmacologic principles Questions
Question 1 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 2 of 5
The following drugs undergo significant enterohepatic circulation:
Correct Answer: A
Rationale: Oestrogens (A) undergo significant enterohepatic circulation, with hepatic conjugates excreted in bile, reabsorbed after gut hydrolysis (e.g., ethinylestradiol), prolonging effects. Atenolol (B) and gentamicin (D) are renally cleared. Rifampicin (C) is biliary but less recycled. Levofloxacin (original E) is renal. This recycling, critical in estrogen pharmacokinetics, extends half-life, impacts oral contraceptive efficacy, and increases drug exposure, a unique elimination pathway.
Question 3 of 5
The following drugs are effectively administered via the sublingual route:
Correct Answer: D
Rationale: Buprenorphine (D) is effective sublingually, bypassing first-pass metabolism for analgesia (e.g., in addiction). Simvastatin (A), carbamazepine (B), and ramipril (C) are oral, not sublingual. Glyceryl trinitrate (original E) is also correct but D is chosen. Sublingual delivery, rapid and hepatic-avoidant, suits buprenorphine's pharmacokinetics, critical for pain or opioid management, enhancing onset.
Question 4 of 5
The following drugs undergo phase II metabolism by hepatic acetylation enzymes (N-acetyltransferases):
Correct Answer: D
Rationale: Isoniazid (D) undergoes phase II acetylation by NAT enzymes, forming acetyl-isoniazid, influenced by acetylator status (fast/slow). Dapsone (A) is correct too but D is chosen. Ciclosporin (B) uses CYP3A. Gentamicin (C) is renally excreted. Hydralazine (original E) is acetylated too. Acetylation, critical in TB therapy, alters isoniazid's toxicity (e.g., neuropathy), a key pharmacogenetic factor, distinguishing phase II from phase I metabolism.
Question 5 of 5
The following statements concerning renal drug handling are correct:
Correct Answer: A
Rationale: Kidneys receive ~20\% of cardiac output (A), ~1 L/min, driving filtration. Option B is true (GFR ~120-130 mL/min). Option C is correct (free drug filters). Option D is valid (active secretion). Option E (original) is false (low lipid solubility reduces reabsorption). High renal blood flow, critical in pharmacokinetics, ensures drug delivery for excretion, a foundational renal handling principle.