Hyperthyroidism medication(PTU) and breastfeeding

[Hana]

Dear Mr Hale,

thank you very much, what a great news for me and my daughter. Today I received my reasults after 3 weeks of taking PTU. It went down in 50% which I think is good sign of curing my thyroid in a good way. Anyway, my doctor still wants me to stop BF and she is telling me that If I will be breastfeeding her, she can get sick with hyperthyrodidism too. I do not trust to this and I believe we both will be fine. I, surely will ask my pediater to check my daughter thyroid too.

Hana

[admin]

Hana:

Both PTU propylthiouracil and Egilok (metoprol) are generally considered safe for breastfeeding. With PTU, i'd suggest you pediatrician do an occasional thyroid check on your infant.

Tom Hale Ph.d.

[Hana]

Hello everyone,
my name is Hana and I am from Slovakia. I was 20 years diadnosed and cured with hypothyroidism. Now I have 11 months old daughter and last week my diagnose changed to HYPERthyroidism. My doctor wants me to stop breastfeeding immediately. I am not sure about that.
My labs numbers were: TSH<0.005mIU/I, T4 58.40pmol/l and aTPO 306kIU/I
She gave me Propycil 1-0-1 and because with this disease i have terrible tachycardia 133, she gave me Egilok 6.25 mg 1-0-0
I will be very glad if you can answer me.
Thank you so much.

[Auchi]

Hello everyone,

I'm currently breastfeeding my 4month old baby and my hyperthyroidism (due to Graves) came back after I stopped taking 5mg of methimazole 4months ago. I was allowed to stopped taking it because my thyroid levels were already stable, again this was after I gave birth. I was having the symptoms of hyperthyroid for a while now and I only had the time to visit my doctor last week. The results were so high I was asked to take 30mg for a day divided into two sessions. This isn't my first time because I also went through this when I gave birth to my first child. However, I had to changed my attending physician because we moved to another city. I just want to confirm if my current doctor's decision is okay because he isn't an endocrinologist. My questions are:

1. Is it better to take 15mg of methimazole twice a day or taking 30mg once a day?

2. Is it considered safe to take this dosage for breastfeeding mothers?

3. How long should I wait, after taking the medicine, to feed my baby?

Thank you so much

[Sandra]

Francp,

If a higher dose of Tapazole did not cause any changes in your toddlers thyroid functions, then a low dose every two days is unlikely to effect them, but this is something I would discuss this with your toddlers pediatrician.

Sandra Lovato R.N.
InfantRisk Center
806-352-2519

[Francp]

Hello again,
it’s been almost a year since diagnosed with graves’ disease. I am taking one pill of tapazol 5mg every two days. I did blood test for thyroid on my toddler 3 times before and they turned fine. But now that the dose of the drug is so low should I keep testing her since I am still breastfeeding her?
thank you

[Sandra]

Aosama,

This is a question for your pediatrician. The results are still in a normal range, but the fact that they changed after just 10 days of therapy is concerning as the levels may continue to increase and we do not want to permanently affect your infants thyroid.

Sandra Lovato R.N.
InfantRisk Center
806-352-2519

[Aosama]

Hi All,

I was diagnosed by hyperthyroidism about 2 months after giving birth. My Dr prescribed me 10mg (2x5mg) per day of Carbimazole since I am breastfeeding.

I made FT3,FT4,TSH exams for my little baby just before taking my first bill and after 10 days of taking my medicine.

Unfortunately my baby’s TSH jumped and t3,t4 affected as well as following:

before Carbimazole;
TSH: 2.146
Free T3: 4.22
Free T4: 1.27

After 10 days on Carbimazole:
TSH: 3.572
Free T3: 4.44
Free T4: 1.12

Do you think i should stop breastfeeding?

[admin]

Francp,

More recent studies found higher transfer rates.

Sandra Lovato R.N.

[Francp]

You said before "Actually 2.3% of methimazole is passed into breast milk" how come it's 5.88-14.7% now?
Please I signed in here to rest my mind about methimazole intake while breastfeeding l. 14% is too much
or you mean the first two hours are high and later decreases

[admin]

Francp,

Methimazole is rated an L2-limited data-probably compatible. The amount that transfers into breast milk is 5.88-14.7% of your dose. The half-life ranges from 6-13 hours. I think since your infant is older breastfeeding twice a day would be minimal exposure or risk, but we do recommend monitoring your child's thyroid functions to be safe. I am afraid zero risk would probably mean waiting 5-6 half-lives to nurse.

Sandra Lovato R.N.
InfantRisk Center
806-352-2519

[Francp]

Hello,
I'm diagnosed with Graves' disease and I started the treatment 2 weeks ago taking methimazole 20mg in 2 divided doses.
however I'm still breastfeeding my 20month old girl.
since the beginning of methimazole I started decreasing breastfeeding from three times to two and now only one time!
but since she's allergic to cow's protein she only gets her milk from me and it was working with us plus she's not taking her day nap anymore because I stopped nursing her through the day.
can I breastfeed her twice a day? And how long should I wait after taking the pills to decrease its exposure? Is 12h waiting the same as 6h for example?
please I'm searching for zero risk

[admin]

Betty,

Carbimazole is a prodrug of methimazole. It is rated an L3-limited data-probably compatible. The amount that transfers into breastmilk is 2.3-5.3% of your dose. Milk levels will depend on your dose, but appear too low to produce clinical effects in the infant. A normal dose is 15-60mg in 2-3 divided doses. We think it is probably ok to breastfeed with this medication if you have your infants thyroid functions monitored regularly and they stay within normal limits, and if you monitor your infant for signs of hypothyroidism.

Propylthiouracil (Propilitiouracilo) is rated an L2-limited data-probably compatible. The amount that transfers into breast milk is 1.8% of your dose. A normal dose is 100mg 3 times a day. This medication is also probably ok. Monitor your infants thyroid functions, and for signs of hypothyroidism.

Either of these medications is probably ok to use in breastfeeding as long as the infants thyroid functions are monitored and they are within normal limits. It appears your doses would be low on either medication, but the decision on which medication to use is up to your Endocrinologist to decide which would work best for you in your situation.

Sandra Lovato R.N.
InfantRisk Center
806-352-2519

[Betty]

Hi there,
I was diagnosed with hypothyroidism during g pregnancy and was taking 62.5 eutirox throughout pregnancy and for one month after my baby boy was born. At that point my bloods showed I was hyper and my doctor took me off the eutirox. In the next blood test six weeks later my levels were the following: TSH 0.01, FT3 6.8, FT4 2.6 (with quite severe symptoms). Here in Spain, the general choice of drug is Carbimazol, but my doctor was aware that I was breastfeeding and it is a level 3 drug, so she prescribed Propilitiouracilo instead, on the lowest dose, 50mg once a day. I've just been to see the endocrinologist and although my FT3 and FT4 are better (2 .4, 1.02) my TSH is still at 0.01 after a month taking Propilitiouracilo. He wants me to go on Carbimazol (5mg + 2.5mg) as he says it is more effective, suggesting I stop breastfeeding if there's a risk to the baby. I really don't want to do that, especially as I will be introducing solids in just over a month and will be feeding less frequently. What do you suggest? Many thanks.

[admin]

Mona,

Carbimazole is rated an L3-limited data-probably compatible. The amount that transfers into breast milk is 2.3-5.3 % of your dose. We think at this low dose it is unlikely to affect your infant, you could probably breastfeed more often if you prefer. We recommend monitoring your infants thyroid functions especially during the first few months of therapy.

Sandra Lovato R.N.
InfantRisk Center
806-352-2519