What are the treatments for thyroid storm?

Treatment of Thyroid Storm

The treatment of thyroid storm requires immediate administration of a standard series of drugs including propylthiouracil or methimazole, potassium iodide or sodium iodide solutions, dexamethasone, and beta-blockers, along with supportive care to prevent mortality. 1

Diagnosis and Clinical Features

Thyroid storm is an extreme hypermetabolic state with high mortality (up to 30%) characterized by:

• Fever
• Tachycardia out of proportion to fever
• Altered mental status (nervousness, restlessness, confusion, seizures)
• Gastrointestinal symptoms (vomiting, diarrhea)
• Cardiac arrhythmias
• Signs of heart failure
• Hepatic dysfunction

An inciting event (surgery, infection, labor, delivery) is often identifiable. Laboratory confirmation includes serum FT3, FT4, and TSH levels, but treatment should not be delayed for test results 1, 2.

Treatment Algorithm

1. First-Line Pharmacological Therapy

• Thionamides - Block new thyroid hormone synthesis:

  • Propylthiouracil (PTU): Preferred historically due to additional benefit of blocking peripheral T4 to T3 conversion 3
  • Methimazole: Equally effective alternative (recent evidence shows no significant difference in mortality or adverse events between PTU and methimazole) 4

• Beta-blockers - Control cardiovascular manifestations:

  • Propranolol: Particularly important in thyroid storm, may require high doses 1, 5
  • Avoid in severe heart failure or bronchospastic disease 5

• Iodine solutions - Block thyroid hormone release:

  • Saturated solution of potassium iodide (SSKI) or sodium iodide
  • Alternatives: Lugol's solution, lithium
  • Important: Administer 1 hour AFTER thionamides to prevent increased hormone synthesis 1

• Corticosteroids - Reduce T4 to T3 conversion and treat potential adrenal insufficiency:

  • Dexamethasone is recommended 1

• Bile acid sequestrants:

  • Cholestyramine to reduce enterohepatic recycling of thyroid hormones 2

2. Supportive Care

• Oxygen therapy
• Antipyretics for fever management
• Appropriate cardiac monitoring
• Treatment of the underlying trigger (infection, etc.)
• Fluid and electrolyte management 1

3. Second-Line Therapies

For patients who fail to respond to standard therapy:

• Therapeutic plasma exchange (TPE): Effective for removing thyroid hormones bound to albumin, autoantibodies, and cytokines 6
• Plasmapheresis: For extreme cases not responding to medication 7, 2
• Thyroidectomy: In cases refractory to medical management 8

Special Considerations

Alternative Administration Routes

When oral administration is not possible:

• Rectal administration of thionamides (as enema or suppository) can be considered 7
• IV methimazole is available in some countries (Europe and Japan) but not in the US 7

Pregnancy

In pregnant women with thyroid storm:

• Propylthiouracil is preferred in the first trimester
• Fetal status should be evaluated with ultrasound, nonstress testing, or biophysical profile
• Delivery during thyroid storm should be avoided unless necessary 1

Monitoring and Follow-up

• Close monitoring of vital signs and mental status
• Serial thyroid function tests
• Monitor for complications of treatment (hepatotoxicity with PTU)
• Transition to definitive management of underlying hyperthyroidism once stabilized

Pitfalls to Avoid

1. Delaying treatment while waiting for laboratory confirmation
2. Administering iodine before thionamides, which can worsen hyperthyroidism
3. Using calcium channel blockers as first-line for rate control instead of beta-blockers
4. Overlooking the precipitating cause of thyroid storm
5. Failing to involve critical care and endocrinology specialists early in management 2

Thyroid storm is a medical emergency requiring prompt recognition and aggressive treatment to reduce the high associated mortality rate.