[little_deer]

#1059015

Hello!

Since this is my first post, I will give a little info about my background. I was diagnosed with Graves’ in 2007 and opted to take the antithyroid treatment route. After an allergic reaction, I switched from methimazole to PTU and have been very stable on it for the last few years.

I am 32 years old. Since I do not see remission in my near future and do not want to gamble with RAI, my husband and I decided to try for our first pregnancy in the hopes that with close monitoring, we could have a healthy baby. I am lucky to have a patient and experienced endocrinologist, who respects and supports my decision and assures me that things will work out.

I am now 17 weeks pregnant.* So far things seem to be going well and we are thrilled. However, I am still very nervous, despite the fact that there are successful pregnancy outcomes with each types of Graves’ treatment, including PTU. It is a class D drug and the possible harm to the fetus is something I hate thinking about. Also, I feel I am on a relatively higher dose than is ideal for pregnancy; 200 mg/day in my second trimester down from 275 mg daily in my first.

I am posting because even this first adjustment is having an effect on me. My pulse has gone up slightly, my eyes are puffy, I feel tired, and I’m more emotionally volatile. This is on top of all the regular pregnancy symptoms. The endo would prefer to see me on the slightly higher end of the reference range to avoid fetal hypothyroidism, goiter, etc., with the goal to be under 200 mg/day in the 3rd trimester. I will continue to have blood tests every 6 weeks and likely an additional ultrasound or so, to monitor the baby’s development.

Is this about standard? I thought I had read somewhere that the ATA recently released new clinical guidelines regarding thyroid disease management in pregnancy, but can’t find them online. Kim, would you happen to know?

I would love to hear from anyone who has been through pregnancy on PTU. I searched the forum and found a few stories. I will update my own as developments unfold, because I want to share this experience with anyone else out there who may be considering a pregnancy on PTU.

Thank you for listening and providing this support forum.

*I want to note that we were able to conceive very quickly! I think the key is that my levels had become very stable. Other things that likely helped, and help with Graves’ management in general:

-a high quality prenatal & omega-3s
-acupuncture, yoga, and meditation
-nutritious diet with lots of greens
-quitting even moderate caffeine (green tea) was one of the best choices I could have made!

Best of luck to everyone out there struggling with thyroid disease.

[adenure]

#1171577

I just wanted to say Congratulations! Pretty soon (within a few weeks) you’ll be able to get your 19/20 week ultrasound and that should help ease some concerns hopefully about your baby’s development. I know there is a more sensitive ultrasound that is done on mothers who are 35 or older; maybe you could ask about having that one given your circumstances? I’m not sure if it would be of any help regarding thyroid issues, but it couldn’t hurt to ask.

I wasn’t diagnosed with Graves until recently- after the birth of my 4 boys- so, I can’t say much about ATD’s and pregnancy. As far as breastfeeding though, know that either drug is okay for nursing. I’m nursing my 5 mo. old on methimazole (5 mg.)– up to 20 mg. is deemed safe- although monitoring your infant’s blood levels is recommended- every 3 mo.

One of my friends is a lactation consultant for LLL and she had 4 babies while dealing with Graves and took PTU- all of her children are healthy with no thyroid issues. She also breastfed them while on treatment.

Alexis

[TammyB]

#1171578

Just wanted to say Hi and congratulations. I was dx about 2yrs ago and my last “baby” will be 21yrs in 2 days, so I don’t have any personal experience to give. However on one of my previous post (I believe it was about Adverse effects of Methimazole) Alexis had responded with some great info on taking ATDs during pregnancy/nursing. Might be of some interest to you. Sounds like you are following your md’s advice and are being monitored appropriately and have a healthly lifestyle with a good support system -so keep up the good work. Remember in just +/- 23wks you will be looking down at the most beautiful gift in the world and would go through these times all over again in a heartbeat. You must keep us posted and I will keep you in my prayers.

[adenure]

#1171579

Here’s ATD info. & breastfeeding per Dr. Thomas Hale:

-Alexis

METHIMAZOLE

Trade Names: Tapazole

Uses: Antithyroid agent

LRC: L3

AAP: Maternal Medication Usually Compatible with Breastfeeding

Methimazole, carbimazole, and propylthiouracil are used to inhibit the secretion of thyroxine. Carbimazole is a prodrug of methimazole and is rapidly converted to methimazole. Milk levels of methimazole depend on maternal dose but appear too low to produce clinical effect. In one study of a patient receiving 2.5 mg methimazole every 12 hours, the milk/serum ratio was 1.16, and the dose per day was calculated at 16-39 µg methimazole.[1] This was equivalent to 7-16% of the maternal dose. In a study of 35 lactating women receiving 5 to 20 mg/day of methimazole, no changes in the infant thyroid function were noted in any infant, even those at higher doses.[2] Further, studies by Lamberg in 11 women, who were treated with the methimazole derivative carbimazole (5-15 mg daily, equal to 3.3 -10 mg methimazole), found all 11 infants had normal thyroid function following maternal treatments.[3] Thus, in small maternal doses, methimazole may also be safe for the nursing mother. In a study of a woman with twins who was receiving up to 30 mg carbimazole daily, the average methimazole concentration in milk was 43 µg/L.[4] The average plasma concentrations in the twin infants were 45 and 52 ng/mL, which is below therapeutic range. Methimazole milk concentrations peaked at 2-4 hours after a carbimazole dose. No changes in thyroid function in these infants were noted. In a large study of over 134 thyrotoxic lactating mothers and their infants. Methimazole therapy was initiated at 10-30 mg/day for one month, and reduced to 5-10 mg/day subsequently. Even at methimazole doses of 20 mg/day, no changes in infant TSH, T4 or T3 were noted in over 12 months of study.[5] The authors conclude 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.

Pregnancy Risk Category: D, D

Lactation Risk Category: L3, L3

Adult Concerns: Hypothyroidism, hepatic dysfunction, bleeding, drowsiness, skin rash, nausea, vomiting, fever.

Pediatric Concerns: None reported in several studies, but propylthiouracil may be a preferred choice in breastfeeding women.

Drug Interactions: Use with iodinated glycerol, lithium, and potassium iodide may increase toxicity.

Relative Infant Dose Range: 2.3%

Adult Dose: 5-30 mg daily.

Alternatives: Propylthiouracil

T½ = 6-13 hours M/P = 1.0
PHL = PB = 0%
Tmax = 1 hour Oral = 80-95%
MW = 114 pKa = 11.64
Vd =
References
1. Tegler L, Lindstrom B. Antithyroid drugs in milk. Lancet 1980; 2(8194):591.
2. Azizi F. Effect of methimazole treatment of maternal thyrotoxicosis on thyroid function in breast-feeding infants. J Pediatr 1996; 128(6):855-858.
3. Lamberg BA, Ikonen E, Osterlund K, Teramo K, Pekonen F, Peltola J, Valimaki M. Antithyroid treatment of maternal hyperthyroidism during lactation. Clin Endocrinol (Oxf) 1984; 21(1):81-87.
4. Rylance GW, Woods CG, Donnelly MC, Oliver JS, Alexander WD. Carbimazole and breastfeeding. Lancet 1987; 1(8538):928.
5. Azizi F, Khoshniat M, Bahrainian M, Hedayati M. Thyroid function and intellectual development of infants nursed by mothers taking methimazole. J Clin Endocrinol Metab 2000; 85(9):3233-3238.

PROPYLTHIOURACIL

Trade Names: PTU, Propyl-Thyracil

Uses: Antithyroid

LRC: L2

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 breastmilk. Reports thus far suggest that levels absorbed by infant are too low to produce side effects.[1] 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.[2] 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, D

Lactation Risk Category: L2, L2

Adult Concerns: Hypothyroidism, liver toxicity, aplastic anemia, anemia.

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.

Relative Infant Dose Range: 1.8%

Adult Dose: 100 mg TID

Alternatives:

T½ = 1.5-5 hours M/P = 0.1
PHL = PB = 80-95%
Tmax = 1 hours Oral = 50-95%
MW = 170 pKa = 12.89
Vd = 0.87
References
1. Cooper DS. Antithyroid drugs: to breast-feed or not to breast-feed. Am J Obstet Gynecol 1987; 157(2):234-235.
2. Kampmann JP, Johansen K, Hansen JM, Helweg J. Propylthiouracil in human milk. Revision of a dogma. Lancet 1980; 1(8171):736-737.

[little_deer]

#1171580

Thank you both for your kind words and encouragement!

I will have a thorough ultrasound next week; we can’t wait! It is so comforting to hear that someone out there was able to safely have 4 children while on ATDs. It is also great that even a dose as high as 400mgs PTU is safe for breastfeeding.

PTU tastes so awful. I never knew what people were complaining so much about until my pharmacy changed manufacturers and suddenly my pills tasted super bad. I feel bad that the baby will likely get to sample that bitterness!

[Kimberly]

#1171581

Hello – Here’s a link to the American Thyroid Association’s guidelines on pregnancy and thyroid disease:

(Note on links: if you click directly on the following links, you will need to use your browser’s “back” button to return to the boards after viewing. As an alternative, you can right-click the link and open it in a new tab or new window).

http://thyroidguidelines.net/sites/thyroidguidelines.net/files/file/thy.2011.0087.pdf

Also, as a side note, people are genetically programmed to find PTU to be bitter tasting. Here’s some additional info:

http://www.smithsonianmag.com/science-nature/A_Matter_of_Taste.html?device=other&c=y

Take care!

[Author]

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