Beta Blockers USMLE Step 1 Practice Question
A 25-year-old man is brought to the emergency department by his partner approximately 2 hours after intentionally ingesting an unknown quantity of aspirin tablets. His partner reports he consumed most of a large bottle during a heated argument. On arrival, his temperature is 38.2°C, blood pressure is 118/74 mmHg, heart rate is 108 bpm, and respiratory rate is 28 breaths per minute. He complains of ringing in his ears and appears diaphoretic and agitated. Arterial blood gas reveals a primary respiratory alkalosis with a concurrent metabolic acidosis. Serial serum salicylate levels are obtained every hour and demonstrate that the drug concentration falls by the same absolute amount each hour rather than by the same percentage. Which of the following best describes this elimination pattern?
Answer choices
- ADistribution phase metabolism
- BFirst order kinetics
- CSaturable zero order kineticsCorrect answer
- DEnterohepatic recirculation
- ECompetitive antagonism
- FNonlinear pharmacokinetics due to protein binding saturation
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