Hypocalcaemia following therapy of thyrotoxicosis in an infant.

UNLABELLED: A 2-mo-old infant born to a mother with Graves' disease and having symptoms of thyrotoxicosis was started on antithyroid drugs. Life-threatening hypocalcaemia requiring high-dose calcium infusions developed 1 mo after starting therapy. Serum alkaline phosphatase and paratharmone levels were elevated. This communication may serve to alert treating physicians about this rare complication in infants with thyrotoxicosis after initiation of antithyroid therapy. CONCLUSION: Severe hypocalcaemia may follow initiation of antithyroid therapy in infants with thyrotoxicosis.