Hypo to Hyper in 6 weeks?

[Paikea]

(I hope this goes to the "Ask a Doctor" forum this time!  I didn't get a message that the allotted number of questions per day had been filled ... If not, I apologize!  I'm not really that bad at the internet, normally.)

Dear Docs,

I am a 31yo woman, diagnosed in late July with Hypothyroidism, from which I am symptomatic (fatigue, fuzzy brain, etc).  My TSH was 10.75 uIU/mL on the initial test.  I was started on 125mcg of Levothyroxine per day.  One day about 6 weeks later, the "missed heartbeats" I had been having for a while increased and I was having muscle pain in my chest that worried me so I went to the urgent care center.  My TSH was tested and had dropped to 0.062 uIU/mL.

My Internist recommended a reduced Levothyroxine dosage of 100mcg/day.  I had my levels re-tested week-before-last (mid-October) and it was only 0.072 uIU/mL.

Again the dosage was reduced, this time to 50mcg/day.  I started that today.

The doctor I saw Friday stated that my body's reaction to the Levothyroxine didn't seem to be "normal" and I should definitely see the Endocrinologist.  I will, but the earliest I could get a new patient appointment is a month from now.  That's too long for me to be wondering what's going on, and even if I'm doing the right thing continuing on with the Levothyroxine.

I'm worried if I do, it could potentially messing up my thyroid even more, if that's possible.  I know it may take time to find a correct dosage, but could it be that I'm not supposed to be on it at all?

Please might you tell me what the quick and dramatic drop in TSH levels might signify?

Thanks!

P.S.  I now seem to have symptoms of both hypo and hyper ... fatigue and fuzzy brain, nervousness, poor sleep, headaches, dizziness.  It's all very annoying!

[Paikea]

Thank you for your comments, RM.

Initially I was almost giddy to learn of my hypothyroid as I'd been complaining of symptoms for a while.  I was told that I would feel like a "new person" in 6-8 weeks of starting Levothyroxine ...  they were right, but in a "still feeling bad, but in a different way" way.  =0)

I think I was expecting too much ... hopefully now I'm in the right frame of mind.  Hopeful but comfortable with the idea that it will take a bit more fine-tuning.

Take care and best of life to you!

[running_man]

I had a similar experience. I'm a 42 year old male. Initially had a TSH of 6.5ish and small thyroid nodules. So my ENT started me on 75mcg of synthroid and referred me to an Endo. I took my synthroid by the book. Every morning at same time and 1 hour before any food. 8 weeks later I was having pronounced heartbeat sensations. My labs showed that my TSH was .01 and my T3/T4 was pretty high. So my Endo had me stop the synthroid.

Retesting after 8 weeks showed my levels more normal TSH 1.5. T3/T4 within range. My very latest labs a few weeks ago showed my TSH at 7.81 and T3/T4 in range. So I seem to be moving back to the hypo side.

My Endo is reluctant to put me back on synthroid until my TSH is > 10 :-( I was thinking a smaller dose might be right for me.

Hang in there, I've discovered that these thyroid issues take a while to resolve.

[Paikea]

Thanks for the reply.  This eases my mind ...

Take care!

[Mark Lupo, M.D.]

You are not doing any further damage to the thyroid itself, but your body needs consistent, normal thyroid levels to function optimally.  With the initial TSH showing moderate hypothyroidism, the dose to start would be about 50-100mcg / day depending on the individual person.  The initial dose may have been simply too high for you as an individual and the quick drop in TSH reflects that.  Others may have done perfectly fine on that dose.