Neonatal thyrotoxicosis presents a difficult management problem. Recent reports have proposed that neonatal thyrotoxicosis may be effectively and safely treated with propranolol hydrochloride alone.1,2 Smith and Howard's report emphasized that their patient did not show clinical improvement while receiving iodides, thioamides, and phenobarbital until the addition of propranolol.3 A recent article has suggested that "beta blockade should be the treatment of choice for neonatal thyrotoxicosis."4 However, we would like to report a case in which propranolol used alone for this purpose caused episodic bradycardia without otherwise improving the patient's clinical status.
Report of a Case.—The patient was a 2,170-g female infant born at 37 weeks' gestation to a 22-year-old multigravida referred to the St Paul (Minn) Ramsey Perinatal Center. One year prior to delivery, the infant's mother had been treated with radioactive iodine for hyperthyroidism. She received 50 μg daily of levothyroxine sodium (Synthroid Tabs) during