SPEX Exam Family Medicine 6

Question 1

A 58-year-old woman with type 2 diabetes, hypertension, and CKD stage 3b (eGFR 32 mL/min/1.73m²) presents for medication review. Her HbA1c is 8.9%. Which antidiabetic agent adjustment is most appropriate?

Accepted Answer

Reduce metformin dose to 500 mg twice daily and add a GLP-1 receptor agonist

Answer

Metformin can be continued with dose reduction at eGFR 30–45 mL/min/1.73m² (reduce to maximum 1000 mg/day); it is contraindicated below eGFR 30. SGLT-2 inhibitors (empagliflozin) lose glycemic efficacy and are generally not recommended below eGFR 45. Sitagliptin requires dose adjustment to 50 mg daily at eGFR 30–50. GLP-1 receptor agonists require no renal dose adjustment and provide cardiovascular and renoprotective benefits, making the combination appropriate here.

Question 2

A 72-year-old man on warfarin for atrial fibrillation presents with a new prescription for fluconazole for oral candidiasis. His INR is currently 2.4 (target 2.0–3.0). What is the most appropriate management?

Accepted Answer

Reduce warfarin dose empirically by 25–50% and recheck INR in 3–5 days

Answer

Fluconazole is a potent CYP2C9 inhibitor and significantly increases warfarin levels, raising bleeding risk. The correct approach is a preemptive warfarin dose reduction of 25–50% with close INR monitoring in 3–5 days. Discontinuing warfarin risks thromboembolic events. The interaction is clinically significant and cannot be ignored. Switching to a DOAC is not warranted for a short-course azole therapy and introduces unnecessary complexity.

Question 3

A previously healthy 34-year-old woman presents with 3 weeks of progressively worsening fatigue, weight gain of 6 lbs, constipation, and cold intolerance. TSH is 12.4 mIU/L and free T4 is 0.6 ng/dL. She is 10 weeks pregnant. What is the most appropriate initial levothyroxine dose?

Accepted Answer

2.0–2.4 mcg/kg/day to account for increased thyroid demand in pregnancy

Answer

Pregnant women with overt hypothyroidism require higher levothyroxine doses than non-pregnant adults — approximately 2.0–2.4 mcg/kg/day — because pregnancy increases thyroid hormone demand (due to increased TBG, hCG stimulation, and increased volume of distribution). Standard non-pregnant replacement (1.6 mcg/kg/day) is insufficient. Slow titration risks prolonged fetal exposure to hypothyroidism, which impairs neurodevelopment. Deferring treatment in overt hypothyroidism during pregnancy is contraindicated.

Question 4

A 45-year-old male firefighter presents with a 2-month history of exertional dyspnea and a nonproductive cough. He is a never-smoker with no significant PMH. PFTs reveal FVC 68% predicted, FEV1 75% predicted, FEV1/FVC ratio 0.88, and DLCO 52% predicted. Chest HRCT shows bilateral basilar honeycombing with traction bronchiectasis. What is the most likely diagnosis?

Accepted Answer

Idiopathic pulmonary fibrosis

Answer

The pattern of bilateral basilar honeycombing with traction bronchiectasis on HRCT is the hallmark of usual interstitial pneumonia (UIP), which corresponds to idiopathic pulmonary fibrosis (IPF). The restrictive PFT pattern with markedly reduced DLCO is consistent. IPF typically presents in men over 50, though it can occur in the mid-40s. Hypersensitivity pneumonitis classically shows upper/mid-lung predominance and air trapping. RB-ILD is seen in smokers. NSIP typically shows ground-glass opacities without honeycombing.

Question 5

A 62-year-old woman with a 10-year history of well-controlled rheumatoid arthritis on methotrexate 20 mg weekly and folic acid presents with an MCV of 108 fL, macrocytic anemia, and oral ulcers. B12 and folate levels are normal. Which mechanism best explains her presentation?

Accepted Answer

Methotrexate-induced folate pathway inhibition despite normal serum folate

Answer

Methotrexate inhibits dihydrofolate reductase (DHFR), blocking the conversion of dietary and supplemental folate into its active form (tetrahydrofolate). This causes functional folate deficiency even when serum folate levels appear normal, because the enzyme needed to activate folate is inhibited. Macrocytosis, anemia, and oral mucositis are classic methotrexate toxicity manifestations. Folic acid supplementation reduces but does not eliminate this risk. Normal serum folate does not rule out methotrexate-induced folate pathway dysfunction.

SPEX Exam Practice Test

SPEX Exam Practice Test

SPEX Exam Family Medicine 6