Audience: endocrine health care professionals, pharmacists, pediatricians
Updated April 21, 2010 — The FDA has added a boxed warning to the label for propylthiouracil to include information about reports of severe liver injury and acute liver failure in adult and pediatric patients using this medication. The reports have included fatalities.
Posted June 6, 2009 — The FDA notified health care 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 that there is an increased risk of hepatotoxicity with propylthiouracil when compared to methimazole. FDA has identified 32 AERS cases (22 adult and 10 pediatric) of serious liver injury associated with propylthiouracil use. Although both propylthiouracil and methimazole are indicated for the treatment of hyperthyroidism due to Graves' disease, health care professionals should carefully consider which drug to use in patients recently diagnosed with Graves' disease.
Physicians should closely monitor patients on propylthiouracil therapy for symptoms of liver injury, especially during the first six months of therapy. Propylthiouracil should not be used in pediatric patients unless the patient is allergic to or intolerant of methimazole, and there are no other treatment options available.
April 21, 2010 — Drug safety communication
June 6, 2009 — Health care professional sheet
