Propylthiouracil poses risk of serious liver injury
Propylthiouracil (PTU) treats hyperthyroidism (including Graves disease) by decreasing the amount of thyroid hormone produced by the thyroid gland. Its notable side effects include a risk of agranulocytosis.Agranulocytosis is a rare, drug-induced blood disorder that is characterized by a severe reduction in the number of white blood cells in the circulating blood.
Propylthiouracil is only available in the United States as a generic medication.Some manufacturers include Actavis Elizabeth, LLC of New Jersey and West-Ward Pharmaceutical Corp, also, of New Jersey.
Recently on June 3, 2009, the FDA alerted healthcare professionals of the seriousness of hepatic reactions related to PTU.It poses a risk of serious liver injury, including liver failure and death in adult and pediatric patients.
Reports to FDA’s Adverse Event Reporting System suggest there is an increased risk of hepatotoxicity with PTU when compared to methimazole.Metimazole is another treatment option for thyroid disorders.FDA has identified 32 cases (22 adult and 10 pediatric) of serious liver injury associated with PTU use. Although both PTU and Metimazole are treatments of hyperthyroidism due to Graves’ disease, healthcare professionals should carefully consider which drug to initiate in a patient recently diagnosed with Graves’ disease.
Physicians should closely monitor patients on PTU therapy for symptoms and signs of liver injury, especially during the first six months of treatment.
PTU should not be used in pediatric patients as a last resort.The FDA suggests that PTU only be used in pediatric patients who are allergic to or intolerant of Metimazole, and there are no other treatment options available.
West-Ward’s label from September 2007 does warn of agranulocytosis and of severe hepatic reactions.It is generally perceived the treatment of hyperthyroidism and not the disease itself causes these serious side effects.
Reports of adverse events associated with Propylthiouracil, including liver failure, should be reported to the FDA.
The FDA can be contacted via:
Online at www.fda.gov/medwatch/report.htm
Phone at 1-800-FDA-1088
Fax at 1-800-FDA-0178, using the MedWatch Form 3500
(available at www.fda.gov/medwatch/ getforms.htm)
Mail, using the postage-paid MedWatch Form 3500 (see above), to MedWatch, 5600
Fishers Lane, Rockville, MD 20852-9787
For more information please see: http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm164162.htm