Reports of Liver Injury Prompt FDA Boxed Warning for Propylthiouracil

Washington, DCThe Food and Drug Administration (FDA) announced today that it has added a Boxed Warning to the label for propylthiouracil, to include information about reports of severe liver injury and acute liver failure, some of which have been fatal, in adult and pediatric patients using this medication. Propylthiouracil has been shown to be effective in reducing thyroid hormone levels and decreasing symptoms associated with hyperthyroidism.

FDA notified healthcare professionals of the risk of serious liver injury, including liver failure and death, with the use of propylthiouracil in adult and pediatric patients.

Reports to FDA's Adverse Event Reporting System (AERS) suggest there is an increased risk of hepatotoxicity with proplythiouracil when compared to methimazole. FDA has identified 32 (AERS) cases (22 adult and 10 pediatric) of serious liver injury associated with propylthiouracil use.