Levothyroxine and Palpitations?

[arndins]

I have Hashimoto's and currently take 75 mcg of levothyroxine. I was increased to this dose about 3.5 weeks ago, when my TSH level was measured at 2.32.

Over the last few days, I have been having some minor heart flutters, most times when I'm on my left side in bed in the morning. Slight palpitations have been occurring at other points in the day, too, for the last three days.

1. Would symptoms such as these (palps) be *caused* by the levothyroxine itself, or by the medicine's effect on the TSH level?

2. I don't want to over-react...should I wait a few more days/weeks and monitor this situation, or should I call my doc about scaling back on the dosage? I feel GREAT on this current dose otherwise, and would hate to prematurely scale back...

3. I was supposed to get my TSH level checked after about 3-6 weeks on this new dose. Do you think 3.5 weeks on a dose is too short of a time to re-check TSH? At how many weeks after a dose change dose TSH reach peak "adjustment" for any new dose?

4. In the midst of all of this, I have an Upper GI/Small Bowel Series scheduled for Monday, and I'm to have no food, water, or medicine after midnight the previous evening (the test is scheduled for 9:00 AM.) Should I just skip my levothyroxine completely that day, or take it in the afternoon when the test is complete, resuming my AM schedule the next day?

Thanks!

[Mark Lupo, M.D.]

1. it's the medication itself, not the TSH effect (TSH helps us gauge the dose however).

2. Some patients have brief palpitations then adjust, but any palpitations may  point to a heart problem and this may need evaluation

3. I usually wait 5-6 weeks at least

4. I tell patients to take the levothyroxine later that day, but ask your doctor.

brand thyroid medications are more consistent than generics

[Lake Lover]

When increasing dosage there can be a short period of adjustment.  If the palp's continue after a week or so you should contact yor doctor.

6 weeks would give you the most accurate lab results so if the palp's stop and you feel good just wait.

I would personally take my mdication after the test is done as it shouldn't be longer than a few hours after your normal dosing, correct?