I'm hypo. I felt awful on Synthroid and I feel much better on Levoxyl.
post #121 of 1011
1/11/07 at 10:07pm
Everyone says Thyroid Meds are safe - where are the long term studies? Same for antidepresants while pregnant. Where are the long term studies that follow the health of children exposed in utero once they reach adulthood? Does anyone know of a resource for this?
I don't know about studies indicating the safety of thyroid meds during pregnancy specifically. There is A LOT of research about the risks of untreated hypo while preg (increased risk of m/c even into the 2nd trimester, neurological defects, mental retardation, etc). Without adequate maternal thyroid hormone, the baby's brain cannot develop normally.
Ok so i have hyper Th. so and i am nursing my son. Gosh i am so worried to take meds and bfeedingf. Does any one know if its safe ?(any meds)
|High thyroid levels (hyperthyroid)
Moms who are hyperthyroid have elevated thyroid hormone (usually T4) levels. Symptoms include weight loss (despite an increased appetite), nervousness, heart palpitations, insomnia, and a rapid pulse at rest.
Hyperthyroidism is not a contraindication for breastfeeding. Per Medications and Mothers' Milk (Hale 2002, p. 417-418, 423-424), only exceedingly low levels of thyroid hormones (both T4 and T3) transfer into breastmilk.
In animal studies, high thyroid levels interfered with milk let-down (Lawrence & Lawrence 1999, p. 522).
* carbimazole (Neo-Mercazole)
* methimazole (Tapazole)
* propylthiouracil (PTU)
Info on selected anti-thyroid meds
Name of medication
Lactation Risk Category**
carbimazole (Neo-Mercazole) yes L3 (moderately safe) (1)
methimazole (Tapazole) yes L3 (moderately safe) (2)
propylthiouracil (PTU) yes L2 (safer) (3)
* Per the AAP Policy Statement The Transfer of Drugs and Other Chemicals Into Human Milk, revised September 2001.
** Per Medications' and Mothers' Milk by Thomas Hale, PhD (2002 edition).
(1) "Carbimazole is a prodrug of methimazole and is rapidly and completely converted to the active methimazole in the plasma." (Hale 2002, p. 112-113)
(2) Hale describes several studies that looked at infant thyroid function (185 mother-infant pairs in all) - all the infants had normal thyroid function after maternal treatment, even when the mother was taking higher doses. One large study (139 mother-infant pairs) observed mothers & babies for over 12 months. "The authors conclude conclusively that both PTU and methimazole can safely be administered during lactation. However, during the first few months of therapy, monitoring of infant thyroid functioning is recommended." Hale notes that "propylthiouracil may be a preferred choice in breastfeeding women." (Hale 2002, p. 465-466)
(3) "Only small amounts are secreted into breastmilk. Reports thus far suggest that levels absorbed by infant are too low to produce side effects... 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." (Hale 2002, p. 603-604)
|I may have an overactive thyroid; can I still breastfeed my baby?
An overactive thyroid gland, also referred to as hyperthyroidism or Graves’ disease, is an important health concern. Thyroid disease is serious as the thyroid controls the body's metabolic processes. According to the LLLI BREASTFEEDING ANSWER BOOK (BAB), any breastfeeding mother with thyroid disease should be under the care of a doctor who is supportive of her desire to breastfeed.
Diagnosis of an overactive thyroid can usually be based on the mother's symptoms as well as a simple blood test. On occasion, radioactive testing is used to diagnose thyroid problems. If radioactive testing is recommended, the mother can ask her physician if the test could be postponed or another, non-radioactive test, be substituted.
If the radioactive test is used, temporary weaning is recommended. "The length of time the mother needs to suspend breastfeeding will depend on the type and dosage of radioactive materials used for the test" (BAB). Radioactivity of breastmilk declines over time, and frequent milk expression will help the mother eliminate the radioactivity from her body more quickly. This milk must be discarded and not fed to the baby. (Frequent milk expression will not hasten the elimination of other drugs from breastmilk.) For pumping information see LLLI FAQs about pumping.
Contact a La Leche League Leader for the most up-do-date information about the time period needed to sufficiently clear radioactivity from breastmilk.
Some medications for overactive thyroid are not concentrated in human milk and result in minimal doses to the breastfed baby If a mother is taking thyroid suppressants, she will need to tell her baby's doctor so the baby can be monitored for thyroid levels. Weaning is usually not necessary. If a doctor insists on weaning, the mother is encouraged to seek a second opinion before weaning. When temporary weaning is recommended, it is important to be sure the risks and benefits have been fully evaluated. If you have questions about the medications you are taking, contact a La Leche League Leader.
If radioactive compounds are used to treat an overactive thyroid, temporary weaning is necessary. The mother will need to pump and discard the milk during this time. Before a mother resumes breastfeeding, her milk must be checked for radioactivity. Your local LLL Leader will be able to share more information and offer support.
|Breastfeeding in mothers with treated Graves’ disease
The question of the safety of lactation during ATD therapy arises frequently 267. Historically, women receiving ATD have been advised against breastfeeding because of the fear that ATD, concentrated in milk, might affect the infant’s thyroid function. Both PTU and MMI are secreted in human milk, although PTU less so because of its more extensive binding to albumin 281-284. In one study evaluating the effects of CMI (15 mg/d) or PTU (150 mg/d) on infants of nursing mothers, there was no evidence of neonatal hypothyroidism in the first weeks of life 285. In another study, serum MMI levels were measured in breastfed infants of thyrotoxic mothers receiving MMI (20-30 mg/d): two hours after MMI ingestion, serum MMI levels in the babies were extremely low, far below the therapeutic range 286. Thus, both with PTU and MMI, only limited quantities of these drugs are concentrated into milk. As long as the doses of MMI or PTU can be kept moderate (MMI <20 mg/d; PTU <250-300 mg/d), the risk for the infant is practically negligible and there is no evidence-based argument to advise mothers against nursing when they take ATD 248,267,287. It is prudent to monitor periodically the infant's thyroid function during the time of ATD administration to the mother, although a recent reassuring study showed that thyroid function in breastfed infants was not affected, even when ATD induced maternal hypothyroidism 288. There is also a possibility that allergic reactions associated with ATD (agranulocytosis or rash) may occur in the infant. While these side effects are rare, they should be kept in mind when evaluating a febrile infant or presence of rash. In summary, within the limitations outlined above, the use of ATD in lactating mothers does not pose a risk to the neonate and appears to be safe.