Propylthiouracil and Breastfeeding
Although the prescribing information advises breastfeeding women to avoid propylthiouracil (PTU), many reliable sources consider the medication safe for nursing mothers. In fact, this used to be the preferred drug for hyperthyroidism treatment until methimazole became available. If your healthcare provider is recommending propylthiouracil, make sure it truly is the best option for your situation.
Can Breastfeeding Women Take Propylthiouracil?Propylthiouracil (PTU) passes through breast milk in humans. While the prescribing information for this drug clearly states that women should never breastfeed while taking it, other reliable sources state that propylthiouracil is compatible with breastfeeding. However, in most situations, a different antithyroid medication, methimazole (Tapazole®), is preferred.
Important Information on Propylthiouracil and BreastfeedingPropylthiouracil passes through breast milk in small amounts. Normal maternal doses do not seem to affect the thyroid function of breastfeeding children.
For quite some time, propylthiouracil was the preferred antithyroid medication for breastfeeding women. However, methimazole is now preferred for almost all individuals -- except pregnant women in the first trimester or people who are allergic to methimazole -- since propylthiouracil has a higher risk of liver failure when compared with methimazole.
If your healthcare provider suggests that you take propylthiouracil while breastfeeding, make sure to verify that methimazole is not a better option for you. If you do take this medication while nursing, your child should be appropriately monitored, especially for rare but serious propylthiouracil side effects, such as low blood cell counts or liver damage (these can be determined using a simple blood test).