Esmolol Use in Thyroid Storm – Evidence‑Based Recommendations

Epidemiology & Rationale

Thyroid storm carries a mortality of 5–25 % and beta‑adrenergic blockade is a cornerstone of its multimodal treatment, as recommended by the American College of Endocrinology and the American Association of Clinical Endocrinologists. 1

A regimen of repeated 5 mg IV boluses every 5 minutes (maximum 15 mg total) may be employed for severe refractory tachycardia, followed by a continuous infusion started 15 minutes after the final bolus. (Praxis Medical Insights, 2026) – expert consensus. 2
The target heart rate in thyroid storm is 80–100 bpm (more permissive than the 50–60 bpm goal for routine thyrotoxicosis). (Praxis Medical Insights, 2026) – expert consensus. 2

Continuous ECG monitoring is mandatory throughout esmolol infusion to promptly detect bradycardia, heart block, or arrhythmias. (Praxis Medical Insights, 2026) – expert consensus. 2
Regular auscultation of the lung fields is required to identify bronchospasm, especially at higher infusion rates where β1‑selectivity may wane. (Praxis Medical Insights, 2026) – expert consensus. 3

Beta‑blockade must be combined with antithyroid drugs (propylthiouracil or methimazole), inorganic iodide (administered ≥1 hour after the antithyroid agent), and corticosteroids, as stipulated by the American College of Endocrinology and the American Association of Clinical Endocrinologists. 1
Esmolol provides rapid symptomatic control of adrenergic hyperactivity but does not treat the underlying excess thyroid hormone; definitive hyperthyroidism therapy must proceed concurrently. (Praxis Medical Insights, 2026) – expert consensus. 3
Aggressive supportive measures—including antipyretics, external cooling, volume resuscitation, and ICU‑level monitoring—are essential components of guideline‑based care. (American College of Endocrinology & AACE) 1

After hemodynamic stability and oral tolerance are achieved, patients should be switched to oral propranolol (40–80 mg every 6–8 hours) or metoprolol (25–50 mg every 6 hours). (Praxis Medical Insights, 2026) – expert consensus. 3
Oral beta‑blocker therapy should be continued until definitive treatment of hyperthyroidism (radioactive iodine or thyroidectomy) results in euthyroidism. (American College of Endocrinology & AACE) 1

Prior to and during esmolol infusion, ensure adequate volume resuscitation because thyroid‑storm patients are often volume‑depleted from fever, diaphoresis, and gastrointestinal losses. (American College of Endocrinology & AACE) 1
In patients with mild‑to‑moderate asthma or COPD, esmolol’s β1‑selectivity makes it preferable to non‑selective agents such as propranolol, though bronchospasm remains a risk. (Praxis Medical Insights, 2026) – expert consensus. 3
Active bronchospastic asthma is a relative contraindication; esmolol should be used only when benefits outweigh risks and no alternative exists. (Praxis Medical Insights, 2026) – expert consensus. 3
Initiate therapy in reactive airway disease at a lower infusion rate (≈ 25 µg/kg/min) with slow titration and continuous pulmonary monitoring. (Praxis Medical Insights, 2026) – expert consensus. 3