What medication is given for a hyperthyroid emergency (thyroid storm)?

Thyroid Storm Medication Management

For thyroid storm, immediately initiate propylthiouracil (PTU) 500-1000 mg loading dose followed by 250 mg every 4 hours, then administer iodine therapy 1-2 hours later, and start propranolol 60-80 mg orally every 4-6 hours (or esmolol IV if hemodynamically unstable), along with dexamethasone 2 mg IV every 6 hours and aggressive supportive care. 1, 2, 3

Immediate Multi-Drug Treatment Protocol

Treatment must begin immediately based on clinical suspicion without waiting for laboratory confirmation, as mortality rises from 10-20% to 75% with treatment delays. 1, 2

Step 1: Thionamide Therapy (Start First)

• Propylthiouracil (PTU) is the preferred first-line agent because it uniquely blocks both thyroid hormone synthesis AND peripheral conversion of T4 to T3. 1, 2, 3
• Dosing: 500-1000 mg loading dose, then 250 mg every 4 hours. 2
• Methimazole 20 mg every 4-6 hours is an alternative if PTU is unavailable, though it lacks the peripheral conversion blocking effect. 1

Step 2: Iodine Therapy (Administer 1-2 Hours AFTER Thionamides)

Critical timing: Never give iodine before thionamides, as this can paradoxically worsen thyroid storm. 1, 2

• Saturated solution of potassium iodide (SSKI): 5 drops every 6 hours. 1, 2
• Alternative: Sodium iodide 500-1000 mg IV every 8 hours. 1
• Alternative: Lugol's solution or lithium if iodine is contraindicated. 1

Step 3: Beta-Blockade

Propranolol is the preferred beta-blocker because it also blocks peripheral T4 to T3 conversion beyond just controlling heart rate. 4, 1, 2, 5

• For stable patients: Propranolol 60-80 mg orally every 4-6 hours. 1, 2
• For hemodynamically unstable patients: Esmolol is preferred due to its rapid onset and short half-life allowing careful titration—loading dose 500 mcg/kg IV over 1 minute, then maintenance infusion starting at 50 mcg/kg/min, titrating up to maximum 300 mcg/kg/min. 1, 2
• If beta-blockers are contraindicated (severe heart failure, bronchospasm): Use diltiazem 15-20 mg (0.25 mg/kg) IV over 2 minutes, then 5-15 mg/h maintenance infusion. 4, 1

Important caveat: One case report documented propranolol-induced circulatory collapse in a patient with underlying thyrocardiac disease, suggesting ultra-short-acting beta-blockers like esmolol may be safer in patients with compromised cardiac function. 6

Step 4: Corticosteroids

• Dexamethasone 2 mg IV every 6 hours to reduce peripheral T4 to T3 conversion and address potential adrenal insufficiency. 1, 2

Essential Supportive Care

• Aggressive IV fluid resuscitation with large-bore IV access. 1
• Antipyretics for fever control (avoid aspirin as it increases free thyroid hormone). 1
• Oxygen therapy as needed. 1, 2
• Identify and treat precipitating factors: infection, surgery, trauma, labor/delivery, medication non-adherence. 1, 2

Hospitalization Requirements

• All patients require hospitalization; severe cases need ICU admission. 1
• Obtain immediate endocrinology consultation. 1
• Monitor for cardiac complications including heart failure and arrhythmias. 1, 2
• Monitor for agranulocytosis with thionamide use (presents with sore throat and fever). 4, 1

Special Considerations for Pregnancy

• Treatment protocol is identical to non-pregnant patients. 1, 2
• PTU is the preferred thionamide in pregnancy. 2
• Monitor fetal status with ultrasound, nonstress testing, or biophysical profile based on gestational age. 1, 2
• Avoid delivery during thyroid storm unless absolutely necessary due to extremely high maternal and fetal mortality risk. 1, 2

Common Pitfalls to Avoid

• Never delay treatment waiting for laboratory confirmation—diagnosis is entirely clinical. 1, 2
• Never give iodine before thionamides—this can worsen the storm by providing substrate for more hormone synthesis. 1, 2
• Exercise caution with propranolol in patients with underlying heart disease—consider esmolol instead for easier titration. 6
• Avoid aspirin for fever control—it displaces thyroid hormone from binding proteins, increasing free hormone levels. 1
• Be aware that beta-blockers may mask clinical signs of hyperthyroidism, and abrupt withdrawal can precipitate exacerbation including thyroid storm. 5