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Liothyronine Pregnancy and Breastfeeding Warnings

Liothyronine is also known as: Cytomel, Triostat

Liothyronine Pregnancy Warnings

Liothyronine has been assigned to pregnancy category A by the FDA. Thyroid hormones do not readily cross the placental barrier. Clinical experience to date has not indicated any adverse effect of thyroid hormone therapy on human fetuses. On the contrary, hypothyroidism may lead to poor pregnancy outcome. Thyroid replacement therapy should be maintained during pregnancy.

See references

Liothyronine Breastfeeding Warnings

Liothyronine is excreted into human milk in small amounts. Liothyronine, in replacement doses, is not expected to cause adverse effects in the nursing infant. The manufacturer recommends that caution be used when administering liothyronine to nursing women. However, adequate replacement doses of thyroid hormone are needed to maintain normal lactation.

See references

References for pregnancy information

  1. "Product Information. Cytomel (liothyronine)." SmithKline Beecham, Philadelphia, PA.
  2. Pekonen F, Teramo K, Ikonen E, Osterlund K, Makinen T, Lamberg BA "Women on thyroid hormone therapy: pregnancy course, fetal outcome, and amniotic fluid thyroid hormone level." Obstet Gynecol 63 (1984): 635
  3. Heinonen O, Slone D, Shapiro S; Kaufman DW ed. "Birth Defects and Drugs in Pregnancy." Littleton, MA: Publishing Sciences Group, Inc. (1977): 297
  4. Potter JD "Hypothyroidism and reproductive failure." Surg Gynecol Obstet 150 (1980): 251-5

References for breastfeeding information

  1. Mizuta H, Amino N, Ichihara K, et al. "Thyroid hormones in human milk and their influence on thyroid function of breast-fed babies." Pediatr Res 17 (1983): 468-71
  2. Franklin R, O'Grady C, Carpenter L "Neonatal thyroid function: comparison between breast-fed and bottle-fed infants." J Pediatr 106 (1985): 124-6
  3. Varma SK, Collins M, Row A, Haller WS, Varma K "Thyroxine, tri-iodothyronine, and reverse tri-iodothyroxine concentrations in human milk." J Pediatr 93 (1978): 803-6
  4. "Product Information. Cytomel (liothyronine)." SmithKline Beecham, Philadelphia, PA.
  5. Hahn HB, Spiekerman AM, Otto R, Hossalla DE "Thyroid function tests in neonates fed human milk." Am J Dis Child 137 (1983): 220-2
  6. Jansson L, Ivarsson S, Larsson I, Ekman R "Tri-iodothyronine and thyroxine in human milk." Acta Paediatr Scand 72 (1983): 703-5

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