The FDA has issued a black box warning for a drug used to treat overactive thyroid or hyperthyroid disease. The FDA has received 34 cases of severe liver injury associated with the drug propylthiouracil. Of those cases of reported liver injury, 13 deaths and 5 liver transplants have been reported. The boxed warning includes a notice to physicians that propylthiouracil is not to be used to treat pediatric patients, except in the extreme instance where no other therapy is appropriate.
Propylthiouracil is a thioamide drug used to treat thyroid issues including Graves disease. The FDA first approved its use in 1947.