Considering RAI - Please tell me about your experiences

[SPencak]

I'm Hyperthyroid & considering RAI. Please tell me about your experience with it...good or bad. I am 30yr old female & do not want to wait 1-2 years to find out if the PTU will work for me, b/c I want to start having children. Have my next appt with Endo in February & would like to be well informed before meeting with him to discuss options.

Also, I read somewhere that it is safe to be pregnant on a low dose of PTU. I currently take 50mg 2x a day. What are your thoughts on this?

[GravesLady]

Usually RAI is a non-event, (it was for me) meaning that one feels nothing unusual. Short-term side effects may include nausea and vomiting soon after treatment, which usually only lasts for a day or two. In addition, some of the RAI may be picked up by the salivary glands around the jaws and under the tongue, causing painful swelling and enlargement of these glands. This is treated by drinking plenty of fluids, sucking on lemon drops (in order to stimulate the flow of saliva) and occasionally over-the-counter pain medicine like aspirin for a few days.
Also about one week (give or take) after RAI you should expect to feel much more hyperthyroid than you are used to. There are a couple of reasons for this. First you will have had to stop the PTU at some point prior to the RAI if you are taking them, in order to assure that the drug does not adversely affect the RAI treatment. So there will no longer be a chemical block working to stop thyroid hormone production. Also as thyroid cells die off from the RAI, about one week or so after the treatment, they will dump their stored supplies of hormone into the body. These cells are not making new hormone, so this period of extra hormone does not last very long.
As for us, long-term studies have not shown there to be any long-term adverse health consequences from our RAI treatment.

Your specific nuclear medical doctor will tell you what instructions to follow or give you written instructions.

Due to the first seventy two hours or so, you are actually shedding radiation that did not make it into your thyroid. I131 is very water soluble, so any of it that did not get trapped by thyroid cells is rather rapidly washed out of the body, primarily via urine, but also in saliva and sweat. So, in those first two or three days, it is theoretically possible for transfer of I131 to someone else - via a kiss, sharing a toothbrush, spoon or fork, etc. We are asked to take extra precautions during these first two/three days as a result.

The issue is that we now know that radiation exposures are cumulative in a lifetime. The sunburn ten years ago, plus the dental x-rays, plus the amount of time spent close to a TV screen, etc. etc. all add up. And, it is possible to be exposed to so much radiation in a lifetime that cells will be damaged and health problems can occur. So the precautions that we are given are akin to the dental technician leaving the room before turning on the x-ray. They are precautions against any unnecessary exposures to radiation. Over time, it is possible for a person to get enough exposure to radiation that it IS toxic to the body. That is why the dental technician leaves the room before turning on your dental x-ray. That radiation alone is not toxic by itself , is not enough to hurt her. But if she turns on enough dental x-rays for enough years, it might add up to too high a dose over time.  That is the reason we take a few precautions with small children, small animals, and with our spouse, after RAI. They do not need any unnecessary radiation exposure added to their lifetime mix. And the smaller the being, the smaller the overall dose of radiation that is tolerable. So we are asked to be careful.

The specific precautions that is needed will depend upon the dose of RAI you are given and how it relates to your uptake, your home situation, work, etc. What one patient is told may be different from what another patient is told -- and BOTH sets of information can be correct. The precautions that are given are designed to protect those around you from any unnecessary exposure to radiation.

It is  assumed that the ablative dose of RAI destroys all or most of the thyroid tissue, however it may not. It may destroy just enough to assure that you are no longer hyperthyroid, but there can still be significant thyroid tissue left. The remaining tissue can be stimulated to produce more excess hormone by increases in antibody action, and can also eventually be destroyed by antibody action. The normal progression of the disease is for the antibodies to wear the thyroid cells out over time.


Some doctors try to adjust the dose of radioactive iodine to destroy only enough of the thyroid gland to bring its hormone production back to normal, without reducing thyroid function too much; others use a larger dose to completely destroy the thyroid. Most of the time, people who undergo this treatment must take thyroid hormone replacement therapy for the rest of their lives. Concern that radioactive iodine may cause cancer has never been confirmed. Radioactive iodine is not given to pregnant or nursing women, because it crosses the placenta and enters the milk and may destroy the fetus's or breastfed infant's thyroid gland.

PTU is the drug of choice if a woman is pregnant with hyperthyroidism because it crosses the placental barrier in smaller concentrations than does Tapazole/methimazole.  I believe it is same for nursing mothers. Another difference is that PTU typically is taken multiple times a day and Tapazole/methimazole can often be taken once a day.

Approx. 20-30% of patients experience remission  with PTUs once.
Second remissions are much less with about 10% of patients who will experience remission a second time.

With Graves' disease the thyroid is permanently diseased and remissions by definition are temporary.  Remission needs to last a year or longer when off  of all thyroid meds to actually be considered a remission. Hyperthyroid levels of hormone will come back at some point in time because remission does not mean "cured."
Some have experienced a 10 year or longer remission before things fell apart again.

For Some even when hormone levels are under control and  back to the normal range will experience symptoms to where its not tolerable.
Tuttle et al (Thyroid 5:243, 1995) have shown that treatment with propylthiouracil before radioactive iodine therapy is associated with a higher treatment failure rate than therapy with radioactive iodine alone in Graves' disease. Thus patients treated with PTU may require a greater radioactive iodine dose to ensure adequate treatment of their disease

I hope the information is not too much to absorb all at once and hope that I didn't repeat myself too much.

Good Luck and best wishes for a Healthy, Happy, Prospers 2008!

[masun]

I had RAI 1 year ago, and  I regrett it.I was on PTU for 13 years, I was pregnant on PTU and everything was right.It is  safe to take 300 mg of PTU daily during pregnancy. I was helthy and full of energy. Now I have hypothreosis wich is corrected by l thyroxine therapy, but I have pain in whole by body 24 ours a day . Neurologists suspect that I have neuromyotonia,  rare autoimune disorder of nerve endings. It was induced by radioactive iodine therapy.  I think I wil not have any healthy day in my life any more. Only pain. Ironicly, I am a doctor, a cardiologist.