ABFAS Pharmacology Fundamentals 3 — Questions and Answers
Question 1: A patient with a penicillin allergy (mild rash) requires antibiotic coverage for a gram-positive foot wound infection. Which is the safest alternative?
- Imipenem
- Cefazolin
- Clindamycin (Correct answer)
- Aztreonam
Correct answer: Clindamycin
Clindamycin is a lincosamide with no cross-reactivity with beta-lactams and provides excellent gram-positive coverage for skin and soft tissue infections.
Question 2: Which pharmacokinetic parameter describes the fraction of an administered drug that reaches systemic circulation unchanged?
- Volume of distribution
- Half-life
- Bioavailability (Correct answer)
- Clearance
Correct answer: Bioavailability
Bioavailability (F) quantifies the proportion of an administered dose that reaches systemic circulation and is influenced by absorption and first-pass metabolism.
Question 3: Which antifungal agent is used topically for onychomycosis prophylaxis and works by inhibiting ergosterol synthesis?
- Nystatin
- Ciclopirox
- Terbinafine (Correct answer)
- Griseofulvin
Correct answer: Terbinafine
Terbinafine inhibits squalene epoxidase, blocking ergosterol biosynthesis and is the topical/oral agent of choice for dermatophyte-caused onychomycosis.
Question 4: A patient taking metformin undergoes a procedure requiring IV contrast. Why should metformin be held perioperatively?
- Metformin inhibits renal excretion of contrast dye
- Contrast nephropathy can reduce metformin clearance, increasing lactic acidosis risk (Correct answer)
- Metformin sensitizes the kidney to contrast-induced free radical damage
- Contrast activates metformin hepatic metabolism leading to toxicity
Correct answer: Contrast nephropathy can reduce metformin clearance, increasing lactic acidosis risk
Contrast-induced nephropathy reduces renal clearance of metformin, causing accumulation and increasing the risk of potentially fatal lactic acidosis.
Question 5: Which corticosteroid preparation has the longest duration of action and is preferred for intra-articular injections in foot joints?
- Methylprednisolone acetate
- Triamcinolone acetonide (Correct answer)
- Hydrocortisone acetate
- Dexamethasone sodium phosphate
Correct answer: Triamcinolone acetonide
Triamcinolone acetonide is an insoluble depot corticosteroid providing 4-6 weeks of intra-articular effect, making it the preferred agent for joint injections.
Question 6: What is the maximum safe dose of lidocaine WITHOUT epinephrine for infiltration anesthesia in a 70 kg adult?
- 200 mg
- 300 mg (Correct answer)
- 500 mg
- 700 mg
Correct answer: 300 mg
The maximum dose of plain lidocaine is 4.5 mg/kg, equating to approximately 300 mg for a 70 kg adult, to minimize systemic toxicity risk.
Question 7: Which drug class reduces postoperative opioid consumption through a multimodal analgesia approach by inhibiting central and peripheral COX enzymes?
- Gabapentinoids
- NSAIDs (Correct answer)
- Alpha-2 agonists
- NMDA antagonists
Correct answer: NSAIDs
NSAIDs reduce prostaglandin synthesis centrally and peripherally, demonstrating a significant opioid-sparing effect as part of multimodal postoperative analgesia.
ABFAS Pharmacology Fundamentals 3
A patient with a penicillin allergy (mild rash) requires antibiotic coverage for a gram-positive foot wound infection.
Which is the safest alternative?