Is Propranolol Alone Really Beneficial in Neonatal Thyrotoxicosis?Bradycardia and Hypoglycemia Evoke the Doctrine of Primum non Nocere

In the July issue of the Journal (134:707-708, 1980), Newman et al¹ described an infant with neonatal thyrotoxicosis treated solely with propranolol hydrochloride, which resulted in episodic bradycardia but no improvement in the patient's clinical status. Since this regimen has been recently described as the "treatment of choice" for neonatal thyrotoxicosis, it seems appropriate to call attention to the limitations and possible complications of using only propranolol in this condition.

Smith and Howard² seem to have been the first to report the use of propranolol in neonatal thyrotoxicosis, in conjunction with propylthiouracil, Lugol's solution, digitalization, and sedation. These authors recommended that in addition to thyroid blockade, propranolol in a dose of 2 mg/kg be used as standard therapy for the management of neonatal thyrotoxicosis. In the following year, Pemberton et al³ described an infant with this condition in whom only propranolol was used as therapy; results were apparently satisfactory. Subsequently