Endocrine drugs (insulin, thyroid medications) Practice Questions

Q: A 25-year-old woman presents to the emergency department with confusion, tachycardia (HR 156), fever (39.8°C), and agitation. She has a history of Graves disease but stopped taking methimazole 3 months ago. She recently had an upper respiratory infection. TSH is <0.01 mIU/L, free T4 is 7.8 ng/dL, and free T3 is markedly elevated. Evaluate the most appropriate comprehensive acute management strategy.

Methimazole, hydrocortisone, propranolol, and iodine solution given 1 hour after antithyroid drug. ***Methimazole, hydrocortisone, propranolol, and iodine solution given 1 hour after antithyroid drug*** - This patient is in **thyroid storm**, a life-threatening emergency requiring therapeutic blockade of hormone synthesis, release, and peripheral conversion. - **Iodine solution** must be administered at least 1 hour after starting antithyroid drugs to prevent the **Wolff-Chaikoff effect** from being bypassed and providing substrate for further hormone production. *Propylthiouracil, propranolol, and supportive care* - While PTU is a valid antithyroid drug, this regimen is incomplete as it misses **corticosteroids** and **iodine**, which are critical for rapid stabilization. - Comprehensive management of thyroid storm always requires a four-pronged approach: blocking synthesis, release, peripheral effects, and peripheral conversion. *Immediate radioactive iodine ablation* - **Radioactive iodine (RAI)** is contraindicated in the acute setting because it can initially cause a release of preformed hormone, worsening the **thyroid storm**. - RAI is a definitive treatment option only after the patient has been rendered **euthyroid** with traditional medical management. *Propranolol, cooling measures, and emergent thyroidectomy* - **Surgery** is not a first-line treatment for thyroid storm and is extremely high-risk in a patient with **tachycardia** and hemodynamic instability. - Emergent thyroidectomy is reserved only for rare, refractory cases where the patient fails to respond to intensive medical therapy. *Methimazole, aspirin for fever, and sedation* - **Aspirin (salicylates)** is strictly contraindicated in thyroid storm because it displaces T4 from **thyroid-binding globulin (TBG)**, increasing free hormone levels. - This regimen lacks **beta-blockers** to control the dangerous adrenergic symptoms (tachycardia) and **iodine** to stop hormone release.

Q: A 68-year-old man with type 2 diabetes, coronary artery disease, and heart failure with reduced ejection fraction (35%) is hospitalized for acute decompensated heart failure. His home medications include metformin, glipizide, and atorvastatin. Blood glucose on admission is 320 mg/dL, creatinine is 2.1 mg/dL (baseline 1.3 mg/dL), and lactate is 3.2 mmol/L. He requires IV diuretics. Analyze the safest glycemic management strategy during hospitalization.

Discontinue all oral agents and initiate basal-bolus insulin regimen. ***Discontinue all oral agents and initiate basal-bolus insulin regimen*** - Hospitalized patients with acute illness require **flexible glycemic control**; basal-bolus insulin is the preferred strategy as it mimics physiological insulin secretion. - Oral agents are generally discontinued in the inpatient setting due to **variable oral intake** and the risk of adverse effects during acute decompensation. *Continue metformin only and add basal insulin* - Metformin is contraindicated in this patient due to **acute kidney injury** (creatinine 2.1 mg/dL) and elevated **lactate levels**, increasing the risk of **lactic acidosis**. - Continuing it during **acute heart failure** decompensation is dangerous because tissue hypoperfusion further exacerbates the risk of metabolic acidosis. *Initiate continuous insulin infusion protocol* - Continuous insulin infusion is typically reserved for **critically ill patients** in the ICU, those with **DKA/HHS**, or specific perioperative scenarios. - This patient is hemodynamically stable enough for subcutaneous management; intravenous protocols require **intensive monitoring** that is unnecessary here. *Discontinue oral agents and use sliding scale regular insulin only* - **Sliding scale insulin (SSI)** alone is discouraged because it is reactive rather than proactive, often leading to poor glycemic control and **glycemic variability**. - SSI fails to provide the **basal insulin** requirements needed to suppress hepatic glucose production, frequently resulting in "rollercoaster" glucose levels. *Continue metformin and glipizide with dose adjustment* - **Glipizide** (a sulfonylurea) carries a significant risk of **hypoglycemia** in the hospital setting where caloric intake may be unpredictable. - As with metformin, sulfonylureas have limited utility in acute illness compared to the **safety and titratability** of subcutaneous insulin.

Q: A 42-year-old woman with hypothyroidism on levothyroxine 125 mcg daily for 5 years presents with symptoms of hypothyroidism despite good compliance. TSH is 12.4 mIU/L. Review of her medications reveals she recently started taking ferrous sulfate for iron deficiency anemia and calcium carbonate for osteopenia prevention, both taken with breakfast along with her levothyroxine. What is the most appropriate management recommendation?

Take levothyroxine 4 hours apart from iron and calcium. ***Take levothyroxine 4 hours apart from iron and calcium*** - Levothyroxine absorption is significantly impaired by **polyvalent cations** such as **iron (ferrous sulfate)** and **calcium carbonate**, which bind the hormone in the GI tract. - To ensure therapeutic efficacy, patients should separate the administration of levothyroxine from these supplements by at least **4 hours**. *Switch from levothyroxine to liothyronine* - **Liothyronine (T3)** is generally not the first-line treatment for primary hypothyroidism and does not address the underlying **malabsorption** issue caused by co-administered supplements. - Switching does not resolve the **drug-drug interaction** that is currently causing the elevated TSH levels. *Switch to intravenous levothyroxine* - **Intravenous levothyroxine** is reserved for severe cases like **myxedema coma** or patients who cannot physically tolerate oral intake. - It is not indicated for manageable **absorption interference** that can be resolved through timing adjustments. *Add liothyronine 5 mcg to current regimen* - Adding **liothyronine (T3)** to a levothyroxine regimen is controversial and doesn't correct the **impaired absorption** of the primary medication. - The goal is to optimize the absorption of the current dose before complicating the regimen with **combination therapy**. *Increase levothyroxine dose to 150 mcg daily* - Increasing the dose while the patient continues taking it with **interfering supplements** is ineffective and may lead to **thyrotoxicity** if the patient later stops the supplements. - The primary clinical problem is **bioavailability**, not an insufficient original dose, making dose escalation inappropriate at this stage.

Question 1

A 25-year-old woman presents to the emergency department with confusion, tachycardia (HR 156), fever (39.8°C), and agitation. She has a history of Graves disease but stopped taking methimazole 3 months ago. She recently had an upper respiratory infection. TSH is <0.01 mIU/L, free T4 is 7.8 ng/dL, and free T3 is markedly elevated. Evaluate the most appropriate comprehensive acute management strategy.

Accepted Answer

Methimazole, hydrocortisone, propranolol, and iodine solution given 1 hour after antithyroid drug

Answer

Propylthiouracil, propranolol, and supportive care

Answer

Immediate radioactive iodine ablation

Answer

Propranolol, cooling measures, and emergent thyroidectomy

Answer

Methimazole, aspirin for fever, and sedation

Question 2

A 34-year-old woman with type 1 diabetes for 20 years is planning pregnancy. She uses an insulin pump with insulin aspart. Her current HbA1c is 7.8%, and she has background diabetic retinopathy and microalbuminuria. She takes lisinopril for blood pressure control. Synthesize the optimal preconception medication management plan considering her complications and pregnancy goals.

Accepted Answer

Continue insulin pump, switch lisinopril to labetalol, target HbA1c <6%, ophthalmology evaluation

Answer

Continue current insulin regimen, continue lisinopril, target HbA1c <7%

Answer

Switch to basal-bolus injection therapy, discontinue lisinopril, target HbA1c <6.5%

Answer

Continue insulin pump, discontinue lisinopril, target HbA1c <6.5%, nephrology consultation

Answer

Switch to NPH/regular insulin, add methyldopa, target HbA1c <7%, increase pump training

Question 3

A 52-year-old woman post-total thyroidectomy for papillary thyroid cancer is being initiated on levothyroxine suppression therapy. Her goal is TSH suppression to <0.1 mIU/L. She has atrial fibrillation controlled on metoprolol and a history of osteoporosis with T-score of -2.8. Evaluate the most significant long-term risk of TSH suppression therapy in this patient and the appropriate monitoring strategy.

Accepted Answer

Accelerated bone loss requiring DEXA monitoring and bisphosphonate therapy

Answer

Increased risk of thyroid storm requiring prophylactic beta-blockade

Answer

Tachycardia-induced cardiomyopathy requiring echocardiography

Answer

Hepatotoxicity requiring liver function monitoring

Answer

Nephrotoxicity requiring serial creatinine monitoring

Question 4

A 68-year-old man with type 2 diabetes, coronary artery disease, and heart failure with reduced ejection fraction (35%) is hospitalized for acute decompensated heart failure. His home medications include metformin, glipizide, and atorvastatin. Blood glucose on admission is 320 mg/dL, creatinine is 2.1 mg/dL (baseline 1.3 mg/dL), and lactate is 3.2 mmol/L. He requires IV diuretics. Analyze the safest glycemic management strategy during hospitalization.

Accepted Answer

Discontinue all oral agents and initiate basal-bolus insulin regimen

Answer

Continue metformin only and add basal insulin

Answer

Initiate continuous insulin infusion protocol

Answer

Discontinue oral agents and use sliding scale regular insulin only

Answer

Continue metformin and glipizide with dose adjustment

Question 5

A 42-year-old woman with hypothyroidism on levothyroxine 125 mcg daily for 5 years presents with symptoms of hypothyroidism despite good compliance. TSH is 12.4 mIU/L. Review of her medications reveals she recently started taking ferrous sulfate for iron deficiency anemia and calcium carbonate for osteopenia prevention, both taken with breakfast along with her levothyroxine. What is the most appropriate management recommendation?

Accepted Answer

Take levothyroxine 4 hours apart from iron and calcium

Answer

Switch from levothyroxine to liothyronine

Answer

Switch to intravenous levothyroxine

Answer

Add liothyronine 5 mcg to current regimen

Answer

Increase levothyroxine dose to 150 mcg daily

Endocrine drugs (insulin, thyroid medications) — MCQs

Endocrine drugs (insulin, thyroid medications) — MCQs

On this page

Practice by Chapter

Want unlimited practice?