Endocrine pharmacotherapy Practice Questions
20 free Endocrine pharmacotherapy practice questions for the USMLE Step 1. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
A patient with type 2 diabetes is started on metformin. Which mechanism best explains how this drug lowers blood glucose?
- A Stimulates insulin secretion by pancreatic β-cells
- B Decreases hepatic gluconeogenesis
- C Slows carbohydrate absorption from the intestine
- D Increases renal glucose excretion
Correct answer: Decreases hepatic gluconeogenesis
Metformin primarily decreases hepatic gluconeogenesis and improves insulin sensitivity without causing hypoglycemia.
A patient on methimazole for Graves disease develops fever and sore throat. Which test should be obtained immediately?
- A TSH level
- B Thyroid uptake scan
- C Complete blood count
- D T3/T4 levels
Correct answer: Complete blood count
Methimazole can cause agranulocytosis; a CBC is needed to evaluate neutrophil count urgently.
A woman with hypothyroidism is switched from levothyroxine to liothyronine. Which major pharmacologic difference should the physician consider?
- A Shorter half-life of liothyronine
- B Lower potency of liothyronine
- C Slower onset of action
- D Reduced risk of tachycardia
Correct answer: Shorter half-life of liothyronine
Liothyronine (T3) has a shorter half-life and greater potency, increasing the risk of adverse cardiovascular effects.
A diabetic patient begins therapy with a sulfonylurea. Which adverse effect is the patient most at risk for?
- A Hypoglycemia
- B Lactic acidosis
- C Hyperkalemia
- D Weight loss
Correct answer: Hypoglycemia
Sulfonylureas increase insulin release and can cause significant hypoglycemia, especially in older adults.
A patient with type 2 diabetes is started on a GLP-1 analog such as liraglutide. Which additional benefit is expected?
- A Weight gain
- B Decreased gastric emptying
- C Increased glucagon secretion
- D Increased appetite
Correct answer: Decreased gastric emptying
GLP-1 analogs slow gastric emptying, aid weight loss, and improve insulin release in a glucose-dependent manner.
A patient with Cushing syndrome undergoes medical therapy before surgery. Which drug inhibits 11β-hydroxylase?
- A Metyrapone
- B Octreotide
- C Ketoconazole
- D Fludrocortisone
Correct answer: Metyrapone
Metyrapone blocks cortisol synthesis by inhibiting 11β-hydroxylase, used diagnostically and therapeutically.
A patient with osteoporosis is started on alendronate. Which adverse effect should be emphasized?
- A Hypoglycemia
- B Esophagitis
- C Pancreatitis
- D Hirsutism
Correct answer: Esophagitis
Bisphosphonates can cause esophagitis; patients should remain upright after taking the medication.
A woman with acromegaly is prescribed octreotide. Which hormone does this drug primarily inhibit?
- A Prolactin
- B Growth hormone
- C TSH
- D ACTH
Correct answer: Growth hormone
Octreotide, a somatostatin analog, suppresses growth hormone secretion and treats acromegaly.
A patient on an SGLT2 inhibitor such as canagliflozin should be monitored for which adverse effect?
- A Urinary tract infections
- B Hypothyroidism
- C Hyperkalemia
- D Symptomatic gallstone disease
Correct answer: Urinary tract infections
SGLT2 inhibitors increase urinary glucose excretion, predisposing patients to UTIs and genital infections.
A patient with hyperprolactinemia is treated with bromocriptine. What is the mechanism of action?
- A Dopamine antagonist
- B Dopamine agonist
- C Estrogen receptor antagonist
- D TRH inhibitor
Correct answer: Dopamine agonist
Bromocriptine is a dopamine agonist that inhibits prolactin secretion from the anterior pituitary.
A patient taking long-term prednisone suddenly stops the medication. Which complication is most likely?
- A Thyroid storm
- B Adrenal crisis
- C Hyperglycemia
- D Hypocalcemia
Correct answer: Adrenal crisis
Chronic steroid therapy suppresses endogenous cortisol production; abrupt withdrawal can precipitate adrenal crisis.
A patient is prescribed propylthiouracil (PTU). Which mechanism distinguishes PTU from methimazole?
- A Inhibition of thyroid peroxidase
- B Inhibition of peripheral T4-to-T3 conversion
- C Blocking iodine uptake
- D Destruction of thyroid tissue
Correct answer: Inhibition of peripheral T4-to-T3 conversion
PTU inhibits both thyroid peroxidase and peripheral T4-to-T3 conversion; methimazole inhibits only the former.
A patient with type 1 diabetes begins insulin glargine. What is a major benefit of this formulation?
- A Rapid onset
- B Long, steady basal coverage
- C Lower risk of hypoglycemia
- D Ability to correct acute hyperkalemia
Correct answer: Long, steady basal coverage
Insulin glargine provides extended, peakless basal insulin coverage for 24 hours.
Which diabetes medication should be avoided in patients with heart failure due to fluid retention?
- A Metformin
- B Pioglitazone
- C Acarbose
- D Sitagliptin
Correct answer: Pioglitazone
Thiazolidinediones like pioglitazone can cause edema and worsen heart failure.
A woman with PCOS is prescribed spironolactone. What symptom is this medication intended to treat?
- A Irregular menstruation
- B Hirsutism
- C Obesity
- D Infertility
Correct answer: Hirsutism
Spironolactone is an androgen receptor antagonist used to reduce hirsutism in PCOS.
A patient receiving insulin therapy experiences hypoglycemia with confusion and sweating. Which is the fastest treatment option?
- A IV dextrose
- B Glucagon injection
- C Oral complex carbohydrates
- D Oral protein supplementation
Correct answer: IV dextrose
IV dextrose rapidly restores blood glucose and is the treatment of choice for severe hypoglycemia with altered consciousness.
A patient with hyperthyroidism is treated with radioactive iodine. Which side effect is most likely?
- A Hypothyroidism
- B Hyperparathyroidism
- C Thyroid storm
- D Addison disease
Correct answer: Hypothyroidism
Radioactive iodine destroys thyroid tissue, often resulting in permanent hypothyroidism.
A diabetic patient is taking acarbose. What is the drug’s primary mechanism?
- A Delays carbohydrate absorption
- B Enhances insulin release
- C Reduces hepatic glucose output
- D Increases insulin sensitivity
Correct answer: Delays carbohydrate absorption
Acarbose inhibits α-glucosidase in the intestine, slowing carbohydrate digestion and glucose absorption.
A patient with adrenal insufficiency requires lifelong replacement therapy. Which medication provides mineralocorticoid activity?
- A Prednisone
- B Hydrocortisone
- C Fludrocortisone
- D Dexamethasone
Correct answer: Fludrocortisone
Fludrocortisone has strong mineralocorticoid activity and is used in Addison disease.
A patient on exenatide reports nausea and early satiety. What explains these symptoms?
- A Rapid gastric emptying
- B Delayed gastric emptying
- C Excess glucagon secretion
- D Increased sympathetic tone
Correct answer: Delayed gastric emptying
GLP-1 agonists delay gastric emptying, contributing to nausea and appetite suppression.