What medications are used to manage thyroid storm?

Management of Thyroid Storm

Thyroid storm requires immediate treatment with a standard series of medications including thionamides (propylthiouracil or methimazole), beta-blockers, iodine solutions, corticosteroids, and supportive care to reduce mortality. 1

First-Line Medications for Thyroid Storm

1. Thionamide Therapy

• Propylthiouracil (PTU) or Methimazole
  • Both inhibit thyroid hormone synthesis
  • PTU has the additional benefit of inhibiting peripheral conversion of T4 to T3 2
  • Recent evidence shows no significant difference in mortality between PTU and methimazole for thyroid storm management 3
  • Treatment should not be delayed while waiting for laboratory confirmation 1

2. Beta-Blockers

• First choice: Propranolol

  • Particularly important in thyroid storm 1
  • Controls tachycardia and other adrenergic symptoms
  • Can be given intravenously in severe cases
  • Blocks peripheral conversion of T4 to T3 4
  • Use with caution in patients with heart failure

• Alternative beta-blockers:

  • Selective beta-1 antagonists may be preferable to non-selective beta-blockers (associated with lower mortality) 5
  • Short-acting beta-blockers (e.g., esmolol) are useful when hemodynamic instability is a concern

3. Iodine Solutions (start 1 hour after thionamides)

• Options include:
  • Saturated solution of potassium iodide (SSKI)
  • Sodium iodide
  • Lugol's solution
  • Lithium (alternative when iodine solutions unavailable) 1
  • Blocks release of preformed thyroid hormone

4. Corticosteroids

• Dexamethasone
  • Suppresses thyroid hormone release
  • Treats potential relative adrenal insufficiency
  • Inhibits peripheral conversion of T4 to T3
  • Note: Higher mortality has been observed in patients requiring corticosteroids, likely reflecting greater disease severity 5

5. Additional Medications

• Cholestyramine - binds thyroid hormones in intestine 6
• Phenobarbital - for severe agitation or seizures 1
• In cases of severe bronchospasm history: consider reserpine, guanethidine, or diltiazem 1

Management Algorithm

1. Immediate Assessment and Stabilization

   • Identify and treat precipitating factors (infection, surgery, trauma, etc.)
   • Provide oxygen, antipyretics, and appropriate monitoring
   • Consider ICU admission

2. Medication Administration Sequence

   • Start thionamide (PTU or methimazole) immediately
   • Administer beta-blocker (propranolol preferred) concurrently
   • Wait 1 hour, then administer iodine solution
   • Add corticosteroids, especially in severe cases
   • Consider cholestyramine for additional binding of thyroid hormones

3. Special Considerations

   • If oral administration is not possible (e.g., GI issues), consider:
     • Nasogastric tube placement distal to any GI pathology 7
     • Therapeutic plasma exchange in extreme cases 7
   • In pregnancy: PTU is traditionally preferred over methimazole in the first trimester

4. Alternative Rate Control Options

   • When beta-blockers are contraindicated:
     • Non-dihydropyridine calcium channel antagonists (diltiazem or verapamil) 1

Monitoring and Follow-up

• Frequent vital sign monitoring
• Serial thyroid function tests
• Assessment of end-organ function
• Evaluate for complications (heart failure, hepatic dysfunction)
• If pregnant, monitor fetal status with ultrasound, nonstress testing, or biophysical profile 1

Pitfalls to Avoid

• Do not administer iodine before thionamides (can worsen thyrotoxicosis)
• Do not use non-selective beta-blockers in patients with severe heart failure
• Do not delay treatment while waiting for laboratory confirmation
• Do not use radioactive iodine (I-131) in acute thyroid storm or pregnancy 1
• Avoid calcium channel blockers as first-line therapy when beta-blockers can be used
• Do not perform cardioversion during thyroid storm unless absolutely necessary

Thyroid storm is a medical emergency with mortality rates up to 30% 7. Early recognition and aggressive multimodal therapy are essential for improving outcomes.