Endocrinology — USMLE Step 3 Practice
Endocrinology on USMLE Step 3 spans diabetes management, thyroid disorders, adrenal emergencies, and pituitary diseases. Pharmacological management and recognizing endocrine crises are recurring exam themes.
Frequently Asked Questions
What is the first-line treatment for type 2 diabetes on USMLE Step 3?
Metformin is first-line for type 2 diabetes in the absence of contraindications (eGFR <30, contrast dye procedures). For patients with established cardiovascular disease, GLP-1 agonists (liraglutide, semaglutide) or SGLT-2 inhibitors (empagliflozin, dapagliflozin) have proven mortality benefit and should be added regardless of HbA1c.
How do you manage diabetic ketoacidosis (DKA)?
DKA management: IV normal saline resuscitation → insulin infusion (0.1 units/kg/hr) → add dextrose when glucose <250 mg/dL to continue insulin until anion gap closes. Aggressively replace potassium (do not start insulin if K+ <3.5 mEq/L). Identify and treat precipitating cause (infection most common).
What is the difference between primary and secondary hypothyroidism on Step 3?
Primary hypothyroidism (Hashimoto thyroiditis most common in US): elevated TSH, low free T4. Secondary (pituitary): low TSH, low free T4. Treatment: levothyroxine; monitor TSH every 6-8 weeks until stable. In pregnancy, thyroid hormone requirements increase — adjust dose in first trimester.
How do you recognize and manage adrenal crisis?
Adrenal crisis presents with hypotension, hyponatremia, hyperkalemia, and hypoglycemia, often triggered by illness or surgery in a patient on chronic steroids. Treatment: IV hydrocortisone 100 mg immediately, then 50-100 mg every 6-8 hours + IV normal saline. Do not wait for cortisol results in an unstable patient.
What is the Step 3 management of hyperthyroidism?
Graves disease is the most common cause. Treat with methimazole (propylthiouracil in first trimester/thyroid storm). Beta-blockers (propranolol) control symptoms acutely. Radioactive iodine ablation or thyroidectomy are definitive. Thyroid storm requires high-dose methimazole, potassium iodide (1 hour after PTU/methimazole), beta-blockers, corticosteroids, and cooling.
Related Articles
- High-Yield Endocrinology for USMLE Step 3: Diabetes, Thyroid, and Adrenal Emergencies
Master endocrinology for USMLE Step 3 — DKA management, diabetes pharmacology, thyroid disorders, adrenal crisis, and pituitary disease.
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