I've been talking to alot of different people through different websites that have various thyroid disorders. Its very strange that a great many of them -hyper and hypo- have acid reflux, GERD, or other upper GI problems. I was diagnosed with Eosinophilic Esophagitis in June of last year. In the middle of all this thyroid stuff! EE is a condition that causes there to be a buildup of eosinophils (allergic white blood cells) in the lining of your esophagus. Its links to severe food allergies. I get chest pain, trouble breathing, and GERD from it. When discussing my EE with others who have eosinophilic disorders, I found that several people with EE or another form of the disorder also had thyroid problems. I don't think a solid study has ever been done on the relationship between thyroid and stomach problems, but my guess is that thyroid probs and stomach probs are very closely related. As far as stomach meds with your thyroid meds is concerned, I was told to take something like Pepcid or one of those at night and my synthroid in the morning. I think the point being to put time between the two meds. I was also told never to use Mylanta or Pepto-bismal or any of those. I have no idea about Xanax though. Ask your pharmacist. :)
I'm going to say yes on the gastro-intestinal problems linked to Hypo, based on experience with no scientific data to back it up.
I'm wondering the same things in regard to stomach acid, and also drug interactions. I'm taking Alprazolam and Ranitidine, among other things. I think I need to space them out differently.
Any suggestions would be helpful.