Why is PTU preferred over methimazole in pregnancy?
The American Thyroid Association and the Endocrine Society guidelines recommend using PTU in the 1st half of pregnancy if drug treatment is needed due to a greater frequency of birth defects with MMI.
Why methimazole is not used in pregnancy?
As this drug crosses the placenta, it can induce goiter and cretinism in the developing fetus; therefore, the lowest possible dose should be used. There are no controlled data in human pregnancy.
Is PTU or methimazole teratogenic?
Methimazole (MMI) and propylthiouracil (PTU) are the standard anti-thyroid drugs used in the treatment of hyperthyroidism in pregnancy. Traditionally, MMI has been considered to have clearer evidence of teratogenicity than PTU.
Can you use PTU during pregnancy?
Both methimazole (MMI) and propylthiouracil (PTU) may be used during pregnancy; however, PTU is preferred in the first trimester and should be replaced by MMI after this trimester. Choanal and esophageal atresia of fetus in MMI-treated and maternal hepatotoxicity in PTU-treated pregnancies are of utmost concern.
What pregnancy category is PTU?
US FDA pregnancy category D: There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
Is PTU safe for pregnancy?
Both methimazole (MMI) and propylthiouracil (PTU) may be used during pregnancy; however, PTU is preferred in the first trimester and should be replaced by MMI after this trimester.
Is methimazole more potent than PTU?
MMI also has superior effect on reducing serum TRAb levels than PTU after 8 weeks and at the end of the study. Conclusion: During the 12-week treatment of Graves’ hyperthyroidism, a single daily dose of 15 mg MMI was much more effective in the induction of euthyroidism than a single daily dose of 150 mg PTU.
Is PTU safe during pregnancy?
Is methimazole pregnancy safe?
This study confirms that methimazole use during the first trimester of pregnancy should be avoided if possible. PTU use is preferred, especially during the 1st trimester. Pregnant mothers with Graves’ disease should consult with their physician to discuss the best treatment recommended for both mother and baby.
Does PTU cause birth defects?
There has not been a confirmed pattern of birth defects to more strongly suggest cause from PTU exposure alone. Additionally, other studies show no increased chance for birth defects. The FDA and ACOG have noted that PTU may be the preferred treatment for hyperthyroidism during the first trimester of pregnancy.
Is PTU more potent than methimazole?
In patients with mild or moderate hyperthyroidism, normal free T4 was achieved at similar rates in the three groups. However, in patients with severe hyperthyroidism (i.e., free T4 ≥7 ng/dL), higher-dose methimazole was more effective than lower-dose methimazole or PTU.