What is the initial treatment approach for a patient presenting with thyroiditis?

Initial Treatment Approach for Thyroiditis

The initial treatment of thyroiditis depends on the phase of disease and symptom severity: use beta-blockers for symptomatic thyrotoxicosis, initiate levothyroxine for TSH >10 mIU/L or symptomatic hypothyroidism, and reserve NSAIDs or corticosteroids for painful thyroiditis. 1, 2

Immediate Assessment and Symptom Management

Thyrotoxic Phase (Hyperthyroidism)

• Beta-blockers are the first-line treatment for symptomatic relief of adrenergic symptoms including palpitations, tremors, tachycardia, and anxiety during the initial hyperthyroid phase 1, 2, 3
• Propranolol 60-80 mg orally every 4-6 hours or atenolol are preferred agents for rate control and symptom management 2
• Antithyroid medications (methimazole, propylthiouracil) are NOT indicated for thyroiditis-induced thyrotoxicosis, as this results from hormone release rather than overproduction 3, 4
• Monitor thyroid function every 2-3 weeks during this phase to detect transition to hypothyroidism 2

Painful Thyroiditis (Subacute Granulomatous)

• NSAIDs are first-line therapy for mild to moderate thyroid pain and tenderness 2, 3, 4
• Systemic glucocorticoids are indicated for severe symptoms, high fever, or pain unresponsive to NSAIDs 2
• Continuation of NSAID monotherapy beyond 1 month is inappropriate if fever persists 2
• Consider hospitalization for patients with severe symptoms affecting daily activities 2

Hypothyroid Phase Treatment

Indications for Levothyroxine Initiation

• Start levothyroxine for symptomatic patients with any TSH elevation 1
• Start levothyroxine for asymptomatic patients with TSH >10 mIU/L 1
• For asymptomatic patients with TSH 4.5-10 mIU/L, monitor TSH every 4-6 weeks without immediate treatment 1
• Women with TSH 4-10 mIU/L who are symptomatic or desire fertility should be considered for treatment 4

Levothyroxine Dosing Strategy

• For patients <70 years without cardiovascular disease: start 1.6 mcg/kg/day based on ideal body weight 1
• For patients >70 years or with cardiac disease: start low at 25-50 mcg/day and titrate gradually 1
• Take as a single dose on an empty stomach, 30-60 minutes before breakfast with a full glass of water 5
• Separate levothyroxine from calcium, iron supplements, and antacids by at least 4 hours to avoid binding and reduced absorption 5

Special Clinical Scenarios

Hashimoto's (Chronic Lymphocytic) Thyroiditis

• Confirm diagnosis with elevated thyroid peroxidase (TPO) antibodies 1, 3
• Lifelong levothyroxine therapy is generally required for overt hypothyroidism 3, 4
• Treatment may reduce goiter size in addition to correcting hypothyroidism 4

Postpartum Thyroiditis

• Occurs within one year of delivery, miscarriage, or medical abortion 3, 4
• Monitor thyroid function regularly as disease may be transient or progress to permanent hypothyroidism 4
• Beta-blockers for initial hyperthyroid phase; levothyroxine for subsequent hypothyroid phase based on TSH criteria above 4

Drug-Induced Thyroiditis (Immune Checkpoint Inhibitors)

• ICI therapy can be continued in most cases of thyroiditis, unlike other immune-related adverse events 6
• High-dose corticosteroids are rarely required for thyroid dysfunction 6
• Monitor thyroid function every 4-6 weeks initially 1

Thyroid Storm (Life-Threatening Emergency)

• Immediate treatment required: propranolol (or alternative beta-blocker), propylthiouracil or methimazole, potassium iodide, dexamethasone, and aggressive IV hydration (at least 2L normal saline initially) 2
• Target heart rate <100 bpm with continuous cardiac monitoring 2
• If beta-blockers contraindicated, use diltiazem or verapamil for rate control 2

Monitoring and Follow-Up

• Reduce or discontinue levothyroxine if TSH becomes suppressed, suggesting overtreatment or recovery of thyroid function 1
• Most subacute thyroiditis cases are self-limited, with spontaneous resolution in several months 3, 4
• If thyrotoxic phase persists beyond 6 weeks, obtain endocrinology consultation 2
• Endocrinology referral also indicated for unusual presentations, difficulty titrating therapy, or concern for central hypothyroidism 1

Critical Pitfalls to Avoid

• Do not use antithyroid drugs for thyroiditis-induced thyrotoxicosis—this is destructive thyroiditis with hormone release, not Graves' disease 3, 4
• Do not assume all thyroid dysfunction is permanent; many patients recover normal function after the triphasic course 3, 4
• Monitor for drug interactions that reduce levothyroxine absorption (calcium, iron, PPIs, bile acid sequestrants) 5
• In elderly or cardiac patients, avoid starting full replacement doses of levothyroxine due to risk of precipitating arrhythmias or angina 1