TSH Supression - Side effect rapid heart rate.

[alice471]

Hi Everyone

After 6 weeks on 150mg thyroxine I am still experiencing rapid heart rate. I can't even walk up the stairs without my pulse racing.

I had an ECG this morning my heart rate was 105 bpm
My blood are TSH <0.05, T4 - 17, T3 - 4.1

My GP has today reduced my medication to 125mg.

I am aware that following treatment for thyroid cancer you need a fairly high dose to supress your TSH to a very low level as mine is now. But I feel that its being on a high dose that is making me feel awaful.  I dont know which is best? feeling better or keeping my TSH levels low.

Has anyone experienced anything similar, also now my dose has been reduced how long do you think it may take for me to start feeling the benefits?

Any info would be greatfully recieved.

[alice471]

Hi, Thanks for your replies.

I just wanted to check - My medication has been reduced is that correct? only one of the above replies mentions feeling the effects of a higher dose?

[utahmomma]

Amy is right and the supression goal is 0.1 for cancer patients.

Do you remember what your BP was today?  If it was high you might want to consider asking your doctor for a short-term prescription for beta blockers until your TSH climbs closer to the target.

Utahmomma
papillary carcinoma

[amela321]

Even for high risk thyroid cancer patients, under .05 TSH is very low.  I think your GP was right in changing your dose.  It can take up to 6 weeks to feel the effects of the higher dose.  If, once your TSH is in the target range (I'm not positive, but I think between .1 and .5) if you still are having a fast resting heart rate, the doctor can put you on a beta blocker.  In the 23 years I've been taking Synthroid I've been on beta blockers at various times and it is very helpful.  

Take care,

Amy
Papillary Thryoid Cancer
Initially diagnosed 1985
Recurrence 2008