Widely Used Heartburn OTC's and Meds Interfere with Thyroid Hormones

Some of the most common and most widely used heartburn and indigestion medication (both prescription and over-the-counter) have been shown to interact with thyroid meds–with the effect of decreasing the absorption of thyroid meds and possibly worsening sign and symptoms of hypothyroidism.

Here are some of them:

• Aluminum containing antacids–Popular brands includeGaviscon, Maalox and Mylanta. These heartburn medications work by neutralizing stomach acids. They are effective and are widely used. However, the aluminum salts in these medications also bind to thyroid medication. In one prospective study, the TSH of the subjects worsened from 2.6 to 7.2 (from normal TSH to abnormally high TSH, which indicates insufficiently managed hypothyroidism).

• PPI–Proton pump inhibitors are commonly used to suppress or stop acid production in the stomach. There are not many studies regarding the interaction of thyroid medication with PPI’s (in this case, lansoprazole, branded as Prevacid). In one study involving 55 subjects, there was a slight increase in TSH by 0.69–not very much compared to the study referred to above for aluminum containing antacids.

• Calcium carbonate antacids–Popular brands includes Tums and Rolaids. Calcium has also been shown to bind to thyroid hormone/thyroid medication. One study showed that TSH worsened from 1.7 to 2.7 when thyroid medication as taken with a calcium supplement.