What I tell fellow thyroid patients is that in this situation, the first thing you'll want to think about is whether or not you might benefit from the addition of supplemental T3.
(A brief recap: Synthroid, Levoxyl and other levothyroxine drugs -- also called "l-thyroxine, and L-T4) are synthetic forms of the T4 thyroid hormone. T4 is the storage hormone, and it must be converted into T3, the active hormone, to be used by the cells. The drug Cytomel is a synthetic form of T3. There is a generic version of Cytomel, and some practitioners work with time-released/sustained-release T3 by prescription from compounding pharmacies. Natural desiccated thyroid drugs like Nature-throid, Armour Thyroid and Erfa contain natural forms of T4, T3 and other thyroid hormones.)
Now, back to the issue of whether or not you might benefit from the addition of T3. The operative question is: will your doctor be willing to even discuss this with you, much less prescribe it? There's no definitive answer.
If you say to the doctor, "Could I benefit from some additional T3?" the response is likely to fit one of four possible scenarios...
- A. The doctor rolls his/her eyes, snorts with derision, shakes his/her head, or otherwise makes it clear that he/she has no interest whatsoever in further discussion about T3.
- B. The doctor respectfully says, "that's not something I'm comfortable with. Sorry."
- C. The doctor thinks about it, and says, "well, let's take a look at your Free T3 level to see what it looks like and then make a decision.
- D. The doctor says, "that's certainly a possibility. Let's try a very low dose of T3 and see how you feel on it. But let's make sure there are no contraindications for you...
If you're working with with Doctor B, well, you might want to ask what his/her rationale is for not being comfortable with adding T3 to a levothyroxine-only thyroid treatment. Here, you might want to mention, or even bring a recap or copy of, the new Danish study that came out in late 2009 in the European Journal of Endocrinology. That study looked at the controversial issue of treatment with synthetic T3 as a supplement to T4-only (levothyroxine) therapy for hypothyroidism. The research reported that 49% of the patients studied preferred the treatment that combined levothyroxine plus a T3 drug, and only 15% preferred levothyroxine-only treatment. (See below for more information on that study, and how you can get a copy to show your doctor.) If Doctor B still categorically refuses to discuss T3 with you and can't satisfy you with a rational explanation, it's time for a new thyroid doctor.
Now, if you are dealing with Doctor C, consider yourself lucky, because Doctor C is thoughtful and open-minded. Ask the doctor what his or her target is for Free T3. And go ahead and get that Free T3 test, keeping in mind that many thyroid experts believe that patients feel best when Free T3 levels are in the top half of the normal range, and even at the 75th percentile and above of the range.
(How does that work? Let's do the math. If the lab's reference range for Free T3 is 2.0-4.4 pg/mL, then the midpoint is halfway between them -- or 3.2 -- and the 75th percentile is 3.8.)
And if you are Doctor D's patient, again, consider youself lucky to have an open-minded and knowledgeable physician. As for those contraindications, doctors tend to be cautious about using T3 in anyone who has a history of heart disease or heart problems, and in the elderly, so T3-savvy doctors will keep this in mind.
More Info on the T4/T3 Study
- New Study Shows that the Addition of T3 is Superior to Levothyroxine/T4-Only Thyroid Treatment for Hypothyroidism -- About.com Recap
- Reference for the Danish Study: Birte Nygaard, Ebbe Winther Jensen, Jan Kvetny, Anne JarlÝv and Jens Faber. "Effect of combination therapy with thyroxine (T4) and 3,5,3'-triiodothyronine versus T4 monotherapy in patients with hypothyroidism, a double-blind, randomised cross-over study," European Journal of Endocrinology, Vol 161, Issue 6, 895-902, December 2009 -- Read the Abstract / Get a Reprint ($25)*
*Don't forget that you can often get a free copy of medical journal articles if you have a medical school, hospital or science library nearby
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