Breastmilk and PTU

[miaka]

I was wondering if anyone knows about PTU and breastmilk. The gov't specialist prescibed this drug for me for my hyperthyroid and told me it's mostly safe for breastfeeding. However, they didn't offer to monitor my baby's thyroid function while I am on the drug. So I'm hesitant to take it. How "safe" is it? Should I wean my baby (7.5 mos) first?

[LLL_Sarah]

PTU has a lactation risk of L2 = SAFER
However it is recommended that the baby be monitored for thyroid function while you are no the drug.

Lactation Risks:
L1: SAFEST
L2: SAFER
L3: MODERATELY SAFE
L4: POSSIBLY HAZARDOUS
L5: CONTRAINDICATED

Below is the page from Medications and Mothers' Milk 2008 by Dr. Thomas Hale (page 804)

PROPYLTHIOURACIL
Trade: PTU
Other Trades: Propyl-Thyracil
Uses: Antithyroid
AAP: Maternal Medication Usually Compatible with Breastfeeding.
Propylthiouracil reduces the production and secretion of thyroxine by the thyroid gland. Only small amounts are secreted into breast milk. Reports thus far suggest that levels absorbed by infant 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 mg/L respectively. No changes in infant thyroid have been reported. PTU is the best of antithyroid medications for use in lactating mothers. Monitor infant thyroid function (T4, TSH) carefully during therapy.

Pregnancy Risk Category: D
Lactation Risk Category: L2
Adult Concerns: Hypothyroidism, liver toxicity, aplastic anemia, amemia
Pediatric. Concerns: None reported, but observed closely for thyroid function
Drug Interactions: Activity of oral anticoagulants may be potentiated by PTU associated anti-vitamin K activity.
Theoretic Infant Dose: 105 ug/kg/day
Relative Infant Dose: 1.84%
Adult Dose: 100mg TID

[miaka]

thanx sarah, i feel much better now.

[CloudCloudC]

Just wanted to let you know I took PTU through two rounds of breastfeeding. My firstborn was a micropreemie born at 23w0d and I pumped for a whole year. He is now 2.5 years old and seems to be fine. I was only able to breastfeed by 2nd one for about 5 months as I dried up but she seems to be fine as well.