ABFAS Pharmacology Fundamentals 2 — Questions and Answers
Question 1: Which opioid analgesic has the highest oral bioavailability and is commonly used for moderate postoperative foot pain?
- Morphine
- Oxycodone (Correct answer)
- Hydromorphone
- Codeine
Correct answer: Oxycodone
Oxycodone has approximately 60-87% oral bioavailability, making it more reliably absorbed than morphine when given orally.
Question 2: A patient on warfarin requires a short course of NSAIDs for postoperative pain. Which NSAID poses the least interaction risk?
- Ibuprofen
- Naproxen
- Celecoxib (Correct answer)
- Ketorolac
Correct answer: Celecoxib
Celecoxib (a selective COX-2 inhibitor) minimally affects platelet aggregation and has a lower risk of clinically significant INR elevation compared to non-selective NSAIDs.
Question 3: What is the primary mechanism by which aminoglycosides cause nephrotoxicity?
- Inhibition of prostaglandin synthesis
- Accumulation in proximal tubular cells causing oxidative damage (Correct answer)
- Direct glomerular basement membrane injury
- Inhibition of renal tubular secretion transporters
Correct answer: Accumulation in proximal tubular cells causing oxidative damage
Aminoglycosides accumulate in proximal tubular cells via megalin-mediated endocytosis, generating reactive oxygen species that cause tubular cell necrosis.
Question 4: Which local anesthetic has the longest duration of action and is most appropriate for postoperative nerve blocks in foot surgery?
- Lidocaine
- Mepivacaine
- Bupivacaine (Correct answer)
- Prilocaine
Correct answer: Bupivacaine
Bupivacaine provides 8-12+ hours of analgesia due to its high lipid solubility and protein binding, making it ideal for postoperative nerve blocks.
Question 5: A diabetic patient develops a foot infection with Staphylococcus aureus resistant to methicillin (MRSA). Which antibiotic is the first-line oral option?
- Amoxicillin-clavulanate
- Trimethoprim-sulfamethoxazole (Correct answer)
- Ciprofloxacin
- Azithromycin
Correct answer: Trimethoprim-sulfamethoxazole
TMP-SMX (Bactrim) is a first-line oral agent for community-acquired MRSA soft tissue infections when susceptibility is confirmed.
Question 6: Which property of vancomycin requires trough-level monitoring to balance efficacy and nephrotoxicity?
- It undergoes extensive hepatic first-pass metabolism
- It has a narrow therapeutic index with concentration-dependent renal clearance (Correct answer)
- It is heavily protein-bound and requires free-drug monitoring
- It induces CYP3A4 and alters its own clearance
Correct answer: It has a narrow therapeutic index with concentration-dependent renal clearance
Vancomycin has a narrow therapeutic window; subtherapeutic troughs lead to treatment failure while supratherapeutic levels increase nephrotoxicity risk.
Question 7: What is the clinical significance of adding epinephrine to a local anesthetic solution for digital nerve blocks in the toes?
- It increases the speed of onset
- It is safe and prolongs duration by reducing systemic absorption
- It is contraindicated due to risk of digital ischemia (Correct answer)
- It prevents systemic toxicity in all patients
Correct answer: It is contraindicated due to risk of digital ischemia
Epinephrine-containing local anesthetics are contraindicated for digital blocks in the toes due to vasoconstriction risk causing ischemia and potential necrosis of end-arterial structures.
ABFAS Pharmacology Fundamentals 2
Which opioid analgesic has the highest oral bioavailability and is commonly used for moderate postoperative foot pain?