Low TSH - Does TSH determine medication requirements or do T3 and T4 levels?

[SR203]

My TSH has decreased from 0.719 to 0.140 in the past year (is that because I started taking my calcium at a different time of day than my Synthroid??) but my T3 and T4 levels have remained fairly stable....Free Thyroxine Index 3.5,...T3 Uptake 30...Thyroxine-T4 11.6.  My MD has reduced my Synthroid, which I have taken for 44 years, from .150 mg to .1375 mg.  I have no hyperthyroid symptoms and am actually colder and more tired than I used to be.  The inability to decrease my weight continues to be an issue.  My pulse is 66 and I have no heart palpitations.  BP 110/66.  Should my TSH level or should my T3 and T4 levels be what determines the amount of medication I require?  I am female and 62 years old.  As an added piece of information, 18 months ago, I learned that I have a non-functioning adrenal adenoma.  Thank you for your help.  

[SR203]

Your way of thinking matched mine completely.  I needed someone else to confirm my thoughts.  I was able to return the Levothroid this morning (since it hadn't been opened and I hadn't taken any) and have the written prescription for Synthroid .150 mg filled.  I will attempt to get an appointment with someone who is more competent ASAP.  Hopefully, the next endocrinologist will spend more than 5 minutes with me in assessing the situation.  You need to know that I truly appreciate your feedback.  

[AR-10]

0.140 is not terribly hyper. If you feel better there, then that is where you should be, as long as it is not affecting your heart.

That is one way to look at it, if the doctor is too dense to order the proper tests and determine what your hormone levels actually are.

Changing your brand of medication was a mistake, and shoddy on the part of whoever did it. That is going to further muddy the waters. You need to get that resolved with the next doctor you see.

In the mean time you will have to limp along on the lower dose of a new brand until you can find a better doctor.

[SR203]

Thank you for responding.  I am to the point of desperation....and need to figure out what to do.  Once again, I have seen a physician who didn't listen to a thing I said.  He looked strictly at the TSH level and paid no attention to my symtoms.  I will be finding another physician but literally need to have my prescription filled today.  Believe it or not, the MD's office gave me a written prescription for one strength of Synthroid, called it medically necessary, but then refused to call the insurance carrier to state the same.....and then called a lower dosage of Levothroid to the pharmacy.    

[AR-10]

Your Free T4 and Free T3 levels should determine your dosage, along with how you feel.

Your TSH should be used as an indicator, not THE dominant factor.

You should space your calcium at least four hours away from your Synthroid. Taking them together or close together will reduce the absorbtion of the Synthroid.

You should be getting a Free T4 and a Free T3 run. They are better tests, although your doctor may not know how to interpret them since he doesn't run them.