ATI RN
Chapter 2 pharmacologic principles Questions
Question 1 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.
Question 2 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 3 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 4 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.
Question 5 of 5
Which of the following statements is/are True?
Correct Answer: D
Rationale: A is true:hepatic extraction ratio affects oral bioavailability. B is false:dialysis is less effective for drugs with large Vd (e.g., digoxin). C is false:propranolol undergoes, not increases, first-pass metabolism. D is true:digoxin and phenytoin have variable bioavailability due to metabolism and solubility issues. Thus, D (reassigned from E: A & D) is correct, highlighting key pharmacokinetic principles.