Wednesday, June 3, 2009

PTU dangerous?

June 3, 2009 — The US Food and Drug Administration (FDA) issued a safety alert today about the risk for serious liver damage, including liver failure, or death with propylthiouracil (PTU) compared with methimazole. Both agents are approved for the treatment of hyperthyroidism associated with Graves' disease.

“Health care professionals should carefully consider which drug to initiate in a patient recently diagnosed with Graves’ disease," Amy Egan, MD, deputy director for safety, Division of Metabolism and Endocrinology Products, in the FDA’s Center for Drug Evaluation and Research, said in a news release. "If PTU therapy is chosen, the patient should be closely monitored for symptoms and signs of liver injury, especially during the first six months after initiating therapy.”


  1. Ah, then methimazole for pregnancy?

    Who said there's nothing new in thyroidology?

  2. There's a really good review out by David Cooper that looks at cases of fulminant liver failure in both adults and children treated with PTU. More than half of these patients needed liver transplantation, and the mortality was pretty high. He also discusses the paucity of information regarding methimazole embryopathy. The ATA is now going to advocate the use of PTU during the first trimester of pregnancy, followed by MMI in the second and third trimesters. I'm writing a review with Dr. Mestman on "Hyperthyroidism & Pregnancy" that will be out in Endocrine Practice later this year that will reiterate that. I'll post the reference for Dr. Cooper's paper soon.

  3. So in the first trimester it is preferable to use PTU and risk "serious liver damage, including liver failure, or death" for the mother rather than methimazole for which there is a "paucity of information regarding methimazole embryopathy"?

    As Dr. Spock might have said: "That is most illogical Captain."

    How about this: PTU in the first trimester, methimazole in the second, iopanoic acid in the third, and lithium for the post-partum phase to also help with potential post-partum depression. Makes about as much sense.

  4. Yikes, don't kill the messenger. The paucity of info on MMI embryopathy is just that - a small number of cases reported. There is no such data with PTU. Just reporting what's in the literature in what's an open forum for discussion. Here's the link to Cooper's paper:

    Cooper DS, Rivkees SA. Putting propylthiouracil in perspective. J Clin Endocrinol Metab. 2009 Jun;94(6):1881-2. Epub 2009 Apr 28.

    PMID: 19401361

    Happy reading...

  5. My apologies, the sarcasm and Star Trekisms were not directed at you, but rather those who create "guidelines". The guidelines appear to be geared more toward CYA then any sound medicine. The problem now is that if anyone veers from the "guidelines", it is always suspected to be improper medicine, regardless of how and why the guidelines were derived.


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