[ozmidwifery] propylthiouracil and breastfeeding

[Anne Clarke]

Dear Jill,   Below is what Thom Hale has in his 'medications and mother's milk' book please consider purchasing a copy (from CAPERS) it is worth that ALL Midwives should have the latest copy with them all the time.   Regards, Anne Clarke Brisbane    Propylthiouracil   Trade name PTU, Propyl-Thyracil Uses - Antithyroid Approved by the American Academy of Paediatrics for use in breastfeeding mothers.   Propylthiouracil reduces the production and secretion of thyroxine by the tyroid gland.  Only small amounts are secreted into breastmilk.  Reports thus far suggest that levels absorbed by infants are too low to produce side effects.  In one study of nine patients given 400 mg doses, mean serum and milk levels were 7.7 mg/L and 0.7/L respectively, which correlated to only 0.025% of the maternal dose.  No changes in infant thyroid have been reported.  PTU is the best of antithyroid medicatins for use in lactating mothers.  Monitor infant thyroid function (T4, TSH) carefully during therapy.   Adult concerns:  Hypothyroidism, liver toxicity, aplastic aneamia, anaemia   Paediatric concerns:  non reported, but observed closely for thyroid function.   Drug interactions:  activity of oral anticoagulants may be potentiated by PTU associated anti-vitamin K activity.   References: 1. Cooper DS Antithyroid drugs: to breastfeed or not to breastfeed AM J Obstet Gynecol 157:234-235, 1987 2. Kampmann JP, et. al., Propylthiouracil in human milk, Lancet1:736-8, 1980