American Board of Internal Medicine (ABIM) Certification Practice Exam

Which of the following conditions does NOT contribute to the need for adjusting apixaban dosage?

1. Age over 80

2. Weight under 60kg

3. Creatinine level of 1.2

4. Recent major surgery

The correct answer is: Creatinine level of 1.2

The rationale for identifying creatinine levels of 1.2 mg/dL as a condition that does not contribute to the need for adjusting apixaban dosage lies in the assessment of renal function and the specific guidelines regarding anticoagulant dosing. Apixaban dosing recommendations are influenced by various factors, including renal function, age, weight, and certain clinical scenarios. Specifically, renal function is evaluated through the creatinine clearance or estimated glomerular filtration rate (eGFR), and a creatinine level of 1.2 mg/dL alone does not inherently indicate that a dosage adjustment is required. The threshold for dosage adjustments usually occurs when renal function is significantly impaired, typically when the eGFR is less than 15-30 mL/min, depending on the clinical guidelines applied. Since a creatinine level of 1.2 may be within an acceptable range for many individuals, especially those with normal body mass and renal function, it does not automatically necessitate a dosage change for apixaban. In contrast, factors like age over 80, weight under 60 kg, and recent major surgery are well-recognized considerations that might require dosage modifications due to their associations with increased risk of bleeding and altered drug metabolism or clearance,