Q. I have suffered with stomach pain and reflux for a long time. I have tried Zantac and Pepcid without much success. I am now taking Prevacid that my doctor prescribed to control excess acid. Even after an increase in dose I am still experiencing gastrointestinal upset. Any ideas?

I also have a thyroid problem. My endocrinologist started me on Synthroid and recently switched me to Levoxyl. Now I am noticing side effects. It seems as if the drug isn’t working the way it used to. I know these drugs are supposed to be equivalent but my body says something different. Should I ask my doctor to put me back on Synthroid?

A. Substituting one brand of levothyroxine (Levoxyl) for another (Synthroid) may require an adjustment in dose. But first, you and your doctor need to consider your stomach problems.

An article in The New England Journal of Medicine (April 27, 2006) shows that people with low stomach acidity do not absorb levothyroxine well and may need a higher dose. The Prevacid you are taking reduces stomach acid.

People infected with stomach bacteria called Helicobacter pylori also seem to have trouble absorbing thyroid hormone. This bug may also be contributing to your GI problems. We discuss the treatment of this infection in our Guide to Digestive Disorders. Our Guide to Thyroid Hormones has more information on levothyroxine and other drugs that may interact with it.

Get The Graedons' Favorite Home Remedies Health Guide for FREE

Join our daily email newsletter with breaking health news, prescription drug information, home remedies AND you'll get a copy of our brand new full-length health guide — for FREE!

  1. Tory

    I’ve had a long history of stomach problems including ulcerative colitis and GERD. The ulcerative colitis is in remission. However a little over a year ago I was diagnosed with thyroid cancer and had two thyroidectomies within one year. I try to take my thyroid medication in the middle of the night when getting up to go to the bathroom. However, sometimes I wake up early morning hungry and feel frustrated because I know I need to take my thyroid medicine first, then my dexilant second, then eat. My doctor said not to take the dexilant with the levothroxine or the levothroxine wouldn’t absorb, I believe. I take other acid reflux medications such as sucralfate & ranitadine throughout the day and at night. My doctor says my levels are within range. However I am suffering from severe exhaustion and heartburn frequently. I also have sinus issues due to allergies, I thought. I was told I have nerve damage from the thyroidectomies and arthritis in my back and hips. My bones and joints ache often. I’m 43! I’ve had major life altering events during this past year as well and am feeling that I may have PTSD. I work full time and some mornings I don’t feel like I should even drive due to exhaustion. Any suggestions on how to manage the acid reflux meds along with the levothroxine? Other suggestions are welcome. Feeling frustrated and alone.

    • Kevin

      I was on Prilosec and Nexium along with Sucralfate for years. Bad stuff. You don’t need it as far as I’m concerned.

      The Prilosec and Nexium caused me to develop a severe Vitamin B-12 and Vitamin D deficiency by reducing stomach acid to the point where I was unable to break down and absorb nutrients. I had to give myself B-12 injections and take high doses of Vitamin D to get back to normal. Obviously, I had to stop taking the above-mentioned medications.

      I also had Thyroid cancer and have to take Synthroid daily after having my thyroid removed. No big deal and all is well now.

      My advice? Stop taking Prilosec, Nexium and Sucralfate. Replace them with Slippery Elm. It works like Sucralfate. Basically, it turns into a mucous-like substance and coats and protects the stomach and gut. Great stuff. My mother and brother were both taking Nexium and stopped, opting for Slippery Elm with the same results I had. Research it. Lots of people have had success using Slippery Elm instead of drugs.

      Additionally, the meds were giving me horrendous headaches, abdominal pain and diarrhea. All gone now. As far as Synthroid, I take one first thing in the morning, wait 30 minutes then I’m good. I only take slippery elm when my stomach is bothering me, not regularly. Since it coats everything, it obviously can interfere with absorption of any and all medications. So, be smart about when you take it.

      For occasional heartburn, baking soda. Works better than anything I’ve ever taken. They say don’t take it if you have high blood pressure because of the salt content. If I remember my chemistry correctly, when stomach acid is neutralized, it is converted into carbon dioxide, water and a salt. In other words, you should burp out carbon dioxide gas. Baking soda is the only antacid I’ve ever taken that makes me burp. My philosophy is, if you ain’t burpin’, it ain’t workin’. Research slippery elm and baking soda. Instructions for taking baking soda for heartburn are on the box; Arm and Hammer brand, don’t know about other brands.

      • Monisha

        Hi Kevin _ What brand of Slippery Elm do you take ?

  2. cc

    OK. I have had Hashimoto’s for 31 years and my thyroid has been totally erratic most of the years. I take 2 different dosages to keep it level now. I was diagnosed with acid reflux from my asthma years ago and for the last 3-4 years I just popped my synthroid with my omeprazole. BIG RED FLAG!!!!
    I got reamed out by my endocrinologist this week. Synthroid needs ACID to metabolize correctly. If you are taking it with your acid reflux meds, that kills the acid in your body. Thus, you synthroid is NOT WORKING.
    I was having thyroid symptoms and it was because of this. I now take my synthyroid on an empty stomach with water and nothing else. You also must not take any calcium for 4 hours after your synthroid. I waited too long though to take the omeprazole because then I was getting acid reflux symptoms…coughing until I choked, stomach upset. So tomorrow I’m going to try it 2 hours after the synthyroid.
    I also read a great book by a dr. in CA. Why am I having thyroid symptoms if my labs are normal. I would highly recommend anyone who has thyroid issues to read it. #1 rule CUT ALL GLUTEN OUT OF YOUR DIET!!!!! It attacks the thyroid. Also #2, make sure your Vitamin D level is in the normal range. That also works very closely with the thyroid.
    My kept running low so I self medicated with 5000 units a day and got it back in the normal range. It also says selenium and dopamine – 2 things in your brain control your thyroid. In my opinion a lot of endocrinologists don’t read up on this stuff.
    After getting off gluten I had more energy than I ever had in my life and the weight fell off me. I have been overweight my entire life and I blame it on the thyroid but then your dr. will tell you it has nothing to do with the thyroid which I TOTALLY DISAGREE!

    • Dolores Kathleen

      I’ve been taking Synthroid for over 20 years and recently had to start taking Dexilant because of Barrett’s Esophagus. Because I have to take both before breakfast I recently asked my pharmacist how much time I needed to leave in between meds. He told me 30 mins. Because I thought this didn’t sound right (too little time) I asked another pharmacist who answered the same thing. After about a month doing this I got hypothyroid symptoms (very tired, weak, shaky, muscle aches) so I checked some of the Thyroid Help sites on the Net where I discovered you must wait at least 2-4 hours between both. So now I take my Synthroid in the middle of the night when I wake up to use the washroom and then the Dexilant in the morning and wait 30 mins before breakfast. After doing that for about 10 days I’m now beginning to feel back to normal again. So the moral of the story is if something doesn’t sound right double check the info!

  3. whisperingsage

    What vitamins were you on that they gave you reflux? If Avapro is for Hypertension, have you tried supplementing with potassium rich foods? That would be fruits and veggies, even rice bran. Kelp meal which is loaded with all the microminerals. On magnesium? Mag and zinc are needed for over 300 cellular processes.
    Look uo the youtube version of Dead Doctors Don’t Lie by Joel Wallach. He’s a vet and advocates for people also to get their minerals.
    Also look up soilminerals dot com, and see how deficient in minerals most foods are anymore. I have a small farm and have found to replace antibiotics with vitamins and minerals in a freechoice form for my animals. So they take waht they need and heal themselves or stop it before it gets started. Mastitis for example is magnesium deficiency. Magnesium is a natural anti inflammatory. Vitamin C is also an antiinflammatory.

  4. mississippi gal

    I’m currently taking synthroid and my levels have remained consistent even thru two pregnancies! I started out eight yrs ago with levothyroxine but I had headaches with it, so I switched to synthroid. It’s more expensive but well worth it! My advice, find what works and take it faithfully! It is painful to try to function in daily life when you feel like a zombie and cannot keep a clear mind! I don’t suffer from reflux ir heartburn as I see many here do, but I have a lactose intolerance and what works for me is honey and cinnamon before or after every meal you know will affect you. No certain mix, I just mix about a Tbsp of honey to a few shakes of cinnamon.

  5. mbm

    Baking soda recipe: 1/2 tsp baking soda in 4 oz. water. Can be taken every 2 hrs. no more than 7 doses per day. The recipe is on the [Arm & Hammer] box.

  6. SCG

    What is the recipe for the baking soda remedy? Have Hashimotos and am on Synthroid .75. Synthroid seems to be working pretty well but I have started having reflux issues. Would like to try the baking soda remedy since taking Prilosec is complicated since you’re supposed to be taking both on an empty stomach. Please let me know.

  7. ja

    200 synthroid, hashamito thyroidist, possible liver disease, acid in stomach, watermelon stomach, arthirtist, fifibro, eye problems, horrible dry skin, sinus problems, bones removed from moth, tmj, gum disease, fast heaet, trouble breathing, sleep apnea, oxygen at night and I am 55, this all started 5 years ago and this all his horrible. I am so tired all the time. I would rather be working than sick like this every day. Everything seems to be attacking me. Not the life I planned for.

  8. Canadiangirl

    Well I can lend some insight to all this…I have hypothyroid and reflux. I never had any reflux or heartburn problems until I was diagnosed with my thyroid problem. Now, I have been to many Doctor’s and specialists as I make full use of our free medical. Anybody with a thyroid problem MUST keep at their Doctors or change your Doctor if they don’t listen to you…. don’t take your doctors word on the dosage until you feel good.
    My first Doctor said that when tested I was within the “range” so I should be fine. Ummmmm wrong! I still didn’t feel at the top of my game so I went back and insisted they up the dosage… waited six weeks, retested and my doctor says… you’re good cause your still within the “range”.. well let me tell you, the “range” is big. I told my doctor that I still didn’t feel totally up to par and that I wanted to increase my dosage again. I argued with him but ultimately won as this is my body and I know best.
    Well in six weeks I was feeling great, was retested and I was still in the “range” but on the higher end of the range and that is where I finally settled as I felt good there. See, so we must keep at our Doctor’s and insist upon what we need as each individual is different and our needs of dosage are different. I do agree after experience that your thyroid med should be taken first thing when u get up on an empty stomach and no food until an hour after. I also believe that thyroid and reflux come hand in hand and each person will just have to find what works for them..i.e. baking soda, prevacid or the many other alternatives out there.
    I take levothyroxine for thyroid and my reflux I use baking soda as I would rather go more natural than more of the man made drugs that have side effects. Also, EVERYONE that has a thyroid problem should have their free T3 and T4 tested with TSH cause in some cases thyroid patients need T3 and maybe this is you ..the person out there who still doesn’t feel well on the medication. Your never going to feel a 100% anymore as we do have a disease and our bodies are not functioning like someone without a thyroid problem but I am here to say… we can feel pretty dam close.

  9. jg

    I’ve been on thyroid replacement for 25 years and have never been “right” on the dosage doctors insist is correct, according to blood tests. When they reduce dosage from effective level I get sinus infections and other immune system related ailments such as Shingles.
    I get really tired of hassling with doctors who know it all. I also am sporting a real issue with reflux but Omeprazole seems to help. I have never, in 25 years, been told not to take antacids with the thyroid replacement or that there is a causal relationship with thyroid meds and reflux. Live and learn but don’t let your doctor run your life.

  10. trineb

    Hi would luv to talk to you more about thyroid and nexium for acid reflux after the holidays?
    I was told also to take both in morning and I am also concerned about my thyroid first and want to continue to take in the mornings, and take the nexium at bed time or evening time (couple hrs before dinner)? This is all confusing, I just want to be healthy and spend time with my beautiful daughters. :)
    Any help and guidance is appreciated. :)

What Do You Think?

We invite you to share your thoughts with others, but remember that our comment section is a public forum. Please do not use your full first and last name if you want to keep details of your medical history anonymous. A first name and last initial or a pseudonym is acceptable. Advice from other commenters on this website is not a substitute for medical attention. Do not stop any medicine without checking with the prescriber. Stopping medication suddenly could result in serious harm. We expect comments to be civil in tone and language. By commenting, you agree to abide by our commenting policy and website terms & conditions. Comments that do not follow these policies will not be posted. Learn how your comment data is processed.

Your cart

Shipping and discount codes are added at checkout.