Practice Test Geeks(ABFAS) American Board of Foot and Ankle Surgery Practice Test
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Pharmacology Fundamentals Flashcards

7 cards from real ABFAS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Pharmacology Fundamentals flashcards as text

  1. Which statement best describes the concept of a drug's therapeutic index (TI)?

    Answer: The ratio of the lethal dose in 50% of subjects to the effective dose in 50% of subjects

    The therapeutic index (TI = LD50/ED50) quantifies the safety margin of a drug; a narrow TI requires careful monitoring (e.g., vancomycin, warfarin).

  2. A patient on warfarin begins taking fluconazole for onychomycosis. What INR change is expected?

    Answer: INR increases due to CYP2C9 inhibition reducing warfarin metabolism

    Fluconazole is a potent CYP2C9 inhibitor that reduces warfarin (S-enantiomer) metabolism, leading to significantly elevated anticoagulation and bleeding risk.

  3. Which local anesthetic toxicity manifests as circumoral numbness, metallic taste, and tinnitus, and represents early CNS toxicity?

    Answer: Systemic local anesthetic toxicity (LAST)

    Early systemic local anesthetic toxicity (LAST) presents with CNS prodromal symptoms including perioral paresthesias, metallic taste, and tinnitus before progressing to seizures and cardiac arrest.

  4. What is the treatment of choice for systemic local anesthetic toxicity (LAST) causing cardiovascular collapse?

    Answer: Intravenous lipid emulsion (Intralipid 20%)

    Intravenous lipid emulsion therapy (Intralipid 20%) acts as a 'lipid sink,' sequestering lipophilic local anesthetics away from cardiac and CNS tissues in LAST emergencies.

  5. Which analgesic mechanism makes gabapentin useful as part of multimodal analgesia in foot and ankle surgery?

    Answer: It binds alpha-2-delta subunits of voltage-gated calcium channels, reducing neuronal excitability

    Gabapentin binds the alpha-2-delta subunit of presynaptic voltage-gated calcium channels, reducing excitatory neurotransmitter release and blunting central sensitization.

  6. In which clinical scenario is ketorolac (IV/IM NSAID) CONTRAINDICATED?

    Answer: Patients with preoperative serum creatinine 2.8 mg/dL

    Ketorolac is contraindicated in patients with pre-existing renal impairment (elevated creatinine) because COX inhibition reduces prostaglandin-dependent renal perfusion, risking acute kidney injury.

  7. A surgeon plans a below-ankle regional block using ropivacaine. What property makes ropivacaine advantageous over bupivacaine for this purpose?

    Answer: Lower cardiotoxicity with similar duration and sensory block quality

    Ropivacaine is less lipophilic than bupivacaine, resulting in lower myocardial sodium channel affinity and significantly reduced cardiotoxicity while maintaining comparable long-acting sensory block.