Does Levothyroxine Cause Heart Burn And Lack Of Appetite?

Posted on Wed, 20 May 2015

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Wed, 20 May 2015 Answered on

Tue, 16 Jun 2015 Last reviewed on

Question : Hi, removed my thyroid 9 days ago (papillary cancer). Started Levothyroxine 125 mg today, and have had HORRIBLE heartburn all day (Tums did nothing, Zantac (75 mg) did nothing) it's relentless. Have not made any changes to my diet (other than a complete lack of appetite today...have to force myself to eat) (I eat healthy). Could the immediate heartburn and lack of appetite come from the levothyroxine? (I took it just as instructed, in the morning on an empty stomach with a full glass of water, then I waited 1 hour before I ate (yoghurt)). What do I do to relieve the heartburn when Tums and Zantac doesn't work? Also, heartburn is not normal for me. I have only had that in my first pregnancy (11 years ago).
I lied, it was zantac 150 mg (sorry!). Also, the surgery was 12 days ago, not 9. I'm starting to have a lot of hypothyroid symptoms. Maybe the heartburn is a hypothyroid symptom? I hope so (cause then the levothyroxine will hopefully correct it)...I have asked my husband to buy Prilosec OTC on the way home.

Answered by Dr. Kathy Robinson (4 hours later)

Brief Answer:
omeprazole is best

Detailed Answer:
Hello,
I am sorry that you are having this problem. It is probably just your body getting used to the levothyroxine. You are taking it properly. Hopefully this heartburn will go away once your body gets adjusted to the thyroid medicine.
Levothyroxine can definitely cause a decreased appetitie. It is possible that the dose is too high but it is impossible to tell until you have been on it for a longer time and get your blood tests rechecked. They like for you to be on a very high dose when you have had thyroid cancer. Try to make sure that you are eating enough calories daily.
It is good that your husband will bring home some prilosec (omeprazole). That should help more with the heartburn than the zantac or tums. Take it 30 minutes before meals once or twice a day.
Having cancer, then surgery, then thyroid replacement is a big adjustment for your body to go through. It will take it several months to adjust.
I hope you are feeling better soon.
Dr. Robinson

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar