NAPLEX Question of the Day
Test your knowledge with a hand-picked multiple-choice question.
A 78-year-old man with a new diagnosis of left-leg DVT is started on warfarin 5 mg daily with enoxaparin bridging. Past medical history includes hypertension and osteoarthritis. Baseline labs: INR 1.0, hemoglobin 12.5 g/dL, platelets 220,000/mm3, serum creatinine 1.1 mg/dL, AST 22 U/L, ALT 20 U/L. He drinks one glass of wine nightly and eats a variable diet that includes salads several times a week. He denies active bleeding, has no history of liver disease, and uses acetaminophen for pain. He will follow up in clinic in 3 days. The pharmacist is counseling him on monitoring and dose adjustments for warfarin therapy.
Which of the following parameters should be monitored most closely in this patient?