Suggest dosage of Cytomel when on 125 mg of Levothyroxine

Posted on Wed, 10 Jun 2015 in Thyroid Problem and Hormonal Problems
Question: I take 125 mcg of levothyroxine and my Free T4 usually measures at 1.7ng/dL.
My T3 (total) is, however, lower than I would like (being about 100 ng/dL).
From my wonderful old retired G.P. I know that a TT3 of about 140 makes me feel normal, energetic, and all around fit as a fiddle.
My (new) Endo only measures T4 and TSH (TSH has always been 0!) and I would like to ask her to give me Cytomel to boost my T3 a bit. I have no confidence in my Endo and until I can rearrange my doctors and/or my health insurance I am stuck with her and I to not trust her to get my dose correct.
My questions are:
1) What is the dose of Cytomel I should ask for to bring my T3 to about 140 ng/dL (remembering that I make 100 ng/dL through my own T4 to T3 conversion)?
2) is Cytomel the only T3 drug, if not, is it the best or what are the others called?
3) What is the equivalent dose of Natural Desiccated Thyroid I should ask for should I get so lucky as to find an Endo that will prescribe this for me? I understand that I should start low and go slow.
Answered by Dr. Binu Parameswaran Pillai 5 hours later
Brief Answer:
Adding T3 is controversial

Detailed Answer:
Good day,

Noted your concern and sorry to hear about your symptoms. Would be very interested to know your Free T3 level. Total T4 and T3 are hardly measured and monitored these days. It is because, Free hormones are the bioactive ones and measuring that would give a better idea about dose titration.

I noted that you had thyroidectomy due to thyroid cancer. In that case, we would like to keep TSH a bit lower than normal for few years.

I can see that your TSH levels are low and any further increase in the dose of levothyroxine or adding cytomel may cause you to lose your bones ( osteoporosis) and may precipitate heart problems at your age. Sorry to say this, but that is the truth.

I understand that some people do have tissue level problems in converting T4 to T3 and hence can continue to suffer from symptoms of hypothyroidism despite having a normal blood levels of T3 and T4. This is a difficult area and a controvesrial one too. Research is ongoing addressing these issues.

No guidelines ( XXXXXXX Thyroid association and Endocrine society) recomend adding Cytomel ( t3) to levothyroxine. I am sorry to say that there no hard evidence in adding Cytomel.

However, you may request your doctor to reduce Levothyroxine and add Cytomel in a small dose on a trial basis if you firmly beleive that adding T3 would improve your symptoms.

Armour thyroid and other natural dessicated ones are also not recommended as the content of T3 and T4 are very variable and it is difficut to titrate the dose.

Please get a Free T3 done. If that is normal, then you should search for an additional cause for your symptoms apart from hypothyroidism.

In clinical practice, most endocrinologists just measure Free T4 and TSH to monitor and titrate the dose.

May i know your Free T3 levels please ( if you have had a recent blood work).

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
Follow up: Dr. Binu Parameswaran Pillai 15 hours later
Hello Dr. BinuPP,
Thank you very much for getting back to me. Here is the other data:
TT4 = 8.9 mcg/dL
TSH = 0.01 mlU/L
FT4 = 1.3 ng/dL
FT3 = 3.6 pg/mL
TT3 = 120 ng/dL
ThyGl AntiBs = <1
ThyPerAntiBs = 1
RT3 LCMS/MS = 24

Now each of these is just about within normal range but:
My TT3/TT4 is 13.5 whereas it should be about 17
My FT3/rT3 is 15 while it should be >20
using TT3/rT3, this is 5 where it should be >10

When I felt great on the old pill my TT3 was 134 ng/dL (they only measured TT3, I do not have old measures of FT3) and it is for the above reasons I would like to boost my T3 (Free variety preferably).

I really appreciate your interest in my problem and you have illuminated some factors which I didn't know about, particularly the bone loss. It also explains why my endo is hesitant in prescribing anything else.

Hope this helps, XXXX

Hello again,
I thought of something else.
I felt great up until December 2012, I started the new pill in January 2013 and within 3 months I had put on 35 lbs and my hypo symptoms started. The effect of the new pill was like going from day to night so quickly. What are the different brands of artificial thyroxine? Maybe there is just something wrong with this pill - I am on generic, I tried a different brand last year but felt no difference. I would like to try different brands but in a more controlled way, i.e. they didn't put the brand name on the one I tried, so I can't rule that one out. it was the (discontinued) brand from XXXXXXX Pharma that I had great success with. Do you know all of the brands so I could try this too?
Again, many, many thanks, XXXXX
Answered by Dr. Binu Parameswaran Pillai 8 hours later
Brief Answer:
Synthroid and Eltroxin are good brands

Detailed Answer:
Good day Ms XXXXXXX

sorry for the delay in reply.

Noted the blood reports. Let me very honest and XXXXXXX These ratios have no real great values. If you have a Free T3 and Free T4 in upper normal range and TSH also in desired range, not to worry. The values can fluctuate mutliple times in a single day ( that is why the normal values are expressed in a wide range). On a single day you could have TT3 of 134 and 120 at two different times of the day.

I agree with you that certain brands may not have enough bioavailability of drug. Synthroid and Eltroxin and two good brands of Levothyroxine available. But i would advice to stick on to same brand of levothyroxine. Please store this pill away from sunlight and heat. Must be kept below 25 degree celcius. I always discourage my patients from keeping thyroid medications in kitchen.
Take it iin empty stomach with a small glass of water, first thing in the morning.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
Answered by
Dr. Binu Parameswaran Pillai


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