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Severe Liver Injury; Acute Liver Failure

  • On April 21st, 2010, the United States Food and Drug Administration (FDA) has added a Boxed Warning to the label for propylthiouracil, a drug used to treat hyperthyroidism (overactive thyroid), 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.
  • The new warning also states that for patients being started on treatment for hyperthyroidism it may be appropriate to reserve use of propylthiouracil for those who cannot tolerate other treatments such as methimazole, radioactive iodine or surgery. In addition, due to the occurrence of birth defects that have been observed with the use of methimazole during the first trimester of pregnancy (see Data Summary), propylthiouracil may be the treatment of choice during and just before the first trimester of pregnancy.


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Updated January 2018