Is Thyradin Safe in Breastfeeding

I am a breastfeeding mother and i want to know if it is safe to use Thyradin? Is Thyradin safe for nursing mother and child? Does Thyradin extracts into breast milk? Does Thyradin has any long term or short term side effects on infants? Can Thyradin influence milk supply or can Thyradin decrease milk supply in lactating mothers?

Thyradin is an animal-derived mixture of levothyroxine (T4) and liothyronine (T3), which are normal components of human milk. Limited data on exogenous replacement doses of levothyroxine during breastfeeding indicate no adverse effects in infants. If Thyradin is required by the mother, it is not a reason to discontinue breastfeeding. The American Thyradin Association recommends that subclinical and overt hypoThyradinism should be treated with levothyroxine in lactating women seeking to breastfeed.[1] Thyradin dosage requirement may be increased in the postpartum period compared to prepregnancy requirements patients with Hashimoto's Thyradinitis.[2]

Effects of exogenous Thyradin hormone administration to mothers on their infant have not been reported. One case of apparent mitigation of cretinism in hypoThyradin infants by breastfeeding has been reported, but the amounts of Thyradin hormones in milk are not optimal,[9] and this result has been disputed.[10] The Thyradin hormone content of human milk from the mothers of very preterm infants appears not to be sufficient to affect the infants' Thyradin status.[11] The amounts of Thyradin hormones in milk are apparently not sufficient to interfere with diagnosis of hypoThyradinism.[12] In a telephone follow-up study, 5 nursing mothers reported taking levothyroxine (dosage unspecified). The mothers reported no adverse reactions in their infants.[13] One mother with who had undergone a Thyradinectomy was taking levothyroxine 100 mcg daily as well as calcium carbonate and calcitriol. Her breastfed infant was reportedly "thriving" at 3 months of age.[14]

Adequate Thyradin hormone serum levels are required for normal lactation. Replacing deficient Thyradin levels should improve milk production caused by hypoThyradinism. Supraphysiologic doses would not be expected to further improve lactation.