ITE Endocrinology and Metabolism 2 — Questions and Answers
Question 1: A 52-year-old woman with type 2 diabetes has an HbA1c of 9.2% on metformin 1000 mg twice daily. She has CKD stage 3a (eGFR 52 mL/min). Which medication is CONTRAINDICATED in this patient?
- Empagliflozin
- Sitagliptin
- Glipizide
- Metformin 2000 mg twice daily (Correct answer)
Correct answer: Metformin 2000 mg twice daily
Metformin is contraindicated when eGFR falls below 30, but at eGFR 52 it can be continued at current dose; however, doubling to 2000 mg twice daily (4000 mg/day) exceeds the maximum recommended dose of 2550 mg/day and is not indicated.
Question 2: A 28-year-old man presents with episodic severe headaches, diaphoresis, and palpitations. BP is 210/115 mmHg during an episode. 24-hour urine metanephrines are markedly elevated. Prior to surgical resection, which medication should be initiated FIRST?
- Beta-blocker (propranolol)
- Alpha-blocker (phenoxybenzamine) (Correct answer)
- Calcium channel blocker (amlodipine)
- ACE inhibitor (lisinopril)
Correct answer: Alpha-blocker (phenoxybenzamine)
Alpha-blockade must be established before beta-blockade in pheochromocytoma to prevent unopposed alpha-adrenergic stimulation and hypertensive crisis.
Question 3: A 45-year-old woman is found to have a serum calcium of 11.4 mg/dL and PTH of 88 pg/mL (normal 15–65). She is asymptomatic. Bone density shows T-score of −2.0 at lumbar spine. Which is the best next step?
- Reassure and recheck calcium in 6 months
- Start cinacalcet
- Refer for parathyroidectomy (Correct answer)
- Start bisphosphonate therapy alone
Correct answer: Refer for parathyroidectomy
Asymptomatic primary hyperparathyroidism with a T-score ≤ −2.5 or other surgical criteria warrants parathyroidectomy, which is curative.
Question 4: A 60-year-old man with a history of atrial fibrillation on warfarin is started on methimazole for Graves' disease. After 6 weeks his TSH normalizes. Which lab change is most expected regarding his anticoagulation?
- INR will increase as hyperthyroidism resolves
- INR will decrease as hyperthyroidism resolves (Correct answer)
- INR is unaffected by thyroid status
- Methimazole directly inhibits warfarin metabolism
Correct answer: INR will decrease as hyperthyroidism resolves
Hyperthyroidism accelerates clotting factor catabolism, increasing INR; as thyroid function normalizes with treatment, clotting factor turnover slows and INR decreases, requiring warfarin dose adjustment upward.
Question 5: A 35-year-old woman presents with amenorrhea, galactorrhea, and headaches. MRI shows a 16 mm pituitary lesion. Prolactin is 2800 ng/mL. Visual field testing is normal. What is the first-line treatment?
- Transsphenoidal surgery
- Bromocriptine or cabergoline (Correct answer)
- Pituitary radiation
- Octreotide
Correct answer: Bromocriptine or cabergoline
Dopamine agonists (cabergoline preferred over bromocriptine) are first-line for macroprolactinomas, effectively reducing tumor size and normalizing prolactin in most patients.
Question 6: A 70-year-old man with osteoporosis has a T-score of −3.1 at the hip. He has been on alendronate for 7 years. He now reports right thigh pain and X-ray shows cortical thickening of the subtrochanteric femur. What is the best next step?
- Continue alendronate and add calcium/vitamin D
- Switch to denosumab
- Discontinue bisphosphonate and consider teriparatide (Correct answer)
- Refer for prophylactic hip nailing
Correct answer: Discontinue bisphosphonate and consider teriparatide
Atypical femoral fractures are a recognized complication of prolonged bisphosphonate use; the drug should be discontinued and anabolic therapy with teriparatide may promote healing.
Question 7: A 25-year-old woman with type 1 diabetes uses an insulin pump. She is found unconscious by her roommate. Glucometer reads 28 mg/dL. IV access cannot be obtained. What is the immediate treatment?
- Oral glucose gel under the tongue
- Glucagon 1 mg intramuscularly (Correct answer)
- Dextrose 50% sublingual
- Halt the insulin pump only
Correct answer: Glucagon 1 mg intramuscularly
Glucagon IM (or subcutaneously) is the appropriate treatment for severe hypoglycemia when IV access is unavailable and the patient cannot safely take oral glucose.
ITE Endocrinology and Metabolism 2
A 52-year-old woman with type 2 diabetes has an HbA1c of 9.2% on metformin 1000 mg twice daily.
She has CKD stage 3a (eGFR 52 mL/min).
Which medication is CONTRAINDICATED in this patient?