Propranolol-Induced Circulatory Collapse in a Patient With Thyroid Crisis and Underlying Thyrocardiac Disease: A Word of Caution.

Thyrotoxic crisis or thyroid storm is a severe form of hyperthyroidism and a rare endocrinological emergency. The cornerstones of medical therapy in thyroid storm include decreasing the levels of circulating T3 in the blood as well as inhibiting the hormone's peripheral effects through β-adrenergic blockade. Propranolol is the preferred agent for β-blockade in hyperthyroidism and thyroid storm due to its additional effect of blocking the peripheral conversion of inactive T4 to active form T3. We report a typical clinical scenario where propranolol was administered in treatment of thyroid storm but an uncommon adverse outcome: circulatory failure from cardiogenic shock warranting vasopressor and inotropic support. Caution with regard to the use long-acting β-blocking agents in patients with underling thyrocardiac disease may prevent this life-threatening adverse effect. Ultra-short-acting β-blockers that are easy to titrate maybe a suitable alternative in this subset of patients.