Propranolol as Treatment for Thyrotoxicosis-Reply

In Reply.—  Dr Biran questions the justification of using propranolol alone in the management of thyrotoxicosis, arguing that ample evidence proves that propranolol does not interfere with thyroid function, and, thus, this drug could not be effective in treating thyrotoxicosis. However, I would emphasize that a thyroid blocking effect of this drug was not the hypothesis on which our study was based. Rather, we questioned the efficacy of β-adrenergic blockade in controlling the clinical manifestations of mild thyrotoxicosis until a natural remission of the disease might intervene. Two of our patients experienced a remission of thyrotoxicosis during long-term propranolol therapy, emphasizing that this disorder is marked by spontaneous exacerbations and remissions¹ and that propranolol can control the symptoms of the disease long enough for a natural remission to occur. Symptomatic improvement, while admittedly incomplete, occurred in all of our patients, and no serious adverse reactions occurred.Dr Biran implies that