Dosage increase and calculating TSH

[craigdog]

Has anyone tried with any success to estimate what your TSH might be after a levo (T4) dosage increase?  I had an increase of 25% and my TSH dropped 47% to 3.38. I then got another increase of 10% and I'm wondering if that would drop my TSH approximately 19%, which I calculated using basic algebra. (if 25% increase got you a 47% drop then a 10% increase would get you a 19% drop)

A 19% drop would get me to 2.74, which is definitely not where I want to be, and I'm 6 weeks from my next blood draw.  It's depressing to think I might likely still be in this mental funk in 6+ weeks.  I feel like my mind is 60% back, but would love to get to 80 or 90% soon, and get my life back.  I'm not sure if this dosage is going to do it.  Thanks all!    

[gimel]

TSH is a pituitary hormone that is affected by so many variables, including the time of day when blood is drawn, that it is totally inadequate as a diagnostic for medicating a thyroid patient. Its usefulness is mainly during early diagnosis.  Of much greater importance is symptoms and the levels of Free T3 and Free T4, and sometimes Reverse T3 as well.

I wouldn't bother spending a minute worrying about the changes in TSH related to meds changes.  Your doctor should be treating you clinically, by testing and adjusting Free T3 and Free T4 as necessary to relieve symptoms, without being constrained by resultant TSH levels.  Symptom relief should be all important, not just test results, and especially not TSH results.

For some insight, have a look at this letter written by a good thyroid doctor for patients that he sometimes consults with from a distance after an initial evaluation and tests.  The letter is then sent to the participating PCP of the patient to help guide treatment.  Take special note of this statement, "the ultimate criterion for dose adjustment must always be the clinical response of the patient."

http://hormonerestoration.com/files/ThyroidPMD.pdf

[craigdog]

I guess the bigger question is...when an experienced doctor orders a dosage increase, are they just wingin' it?  Or is there a scientific method of calculating an increase of synthroid?

[craigdog]

The other mathimatical way to look at it might be...if a .25 increase dropped my TSH 3.05, then a .10 increase would drop it approximately 1.22.  That would get me to 2.16, which would be better than the 2.74.  I assume this is all a waste of time and there's no reliable way to calculate how your body might react.