Liver Failure with Propylthiouracil

FDA is notifying healthcare professionals about the risk of serious and possibly fatal liver injury associated with propylthiouracil, an anti-thyroid drug used to treat Graves' disease. Propylthiouracil is generally considered second-line therapy in Graves' disease. The drug of choice in most cases is methimazole, because it has been associated with fewer cases of serious liver damage than propylthiouracil. Children are especially vulnerable to liver damage with propylthiouracil. FDA has identified 10 pediatric cases of serious liver injury from propylthiouracil, and none from methimazole. The risk profile is different for patients in the first trimester of pregnancy, however, since methimazole has been associated with embryopathy and propylthiouracil has not. FDA is working to change the propylthiouracil prescribing information to reflect the risk of hepatotoxicity, and the American Thyroid Association plans to update its treatment guidelines for Graves' disease. In the meantime, FDA is recommending that clinicians reserve the use of propylthiouracil for patients who cannot take methimazole because of allergy or intolerance, or for patients in the first trimester of pregnancy. Propylthiouracil should not be used in children unless they cannot take methimazole and there are no other treatment options available. If propylthiouracil is prescribed, patients should be closely monitored for liver injury, especially during the first six months of treatment. Advise patients to promptly report symptoms such as fatigue, weakness, vague abdominal pain, loss of appetite, itching, easy bruising, or yellowing of the eyes or skin. If liver injury is suspected, the drug should be discontinued and the patient evaluated. FDA Patient Safety News: August 2009 For more information, please see our website: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/psn/transcript.cfm?show=89#1