Sir.—In the July and September issues of the Journal (1980;134:707-708 and 1980;134:819-820), there was some discussion regarding the use of propranolol hydrochloride in the treatment of neonatal thyrotoxicosis by Newman et al and by Gardner. We would like to bring to your attention a case of ours that further illustrates the need for caution concerning this treatment. The case was presented at the 14th annual Research Symposium at Mercy Hospital of Buffalo, NY, on June 5, 1980, by one of the authors (B.G.).
Report of a Case.—The patient was a 2,920-g female infant, born after 36 weeks of gestation to a 29-year-old mother who was under treatment with propylthiouracil for hyperthyroidism during the last trimester of pregnancy. The baby had bilobate goiter on examination and was hypothyroid, as ascertained by in vitro thyroid studies (serum thyroid-stimulating hormone [TSH] level, 60.5 μU/mL; serum free thyroxine [T4] level, 0.1