Regular Use of Stomach Acid Inhibitors

Q:  What is the effect on the gastric system of using stomach acid inhibitors such as Pepcid, Tagamet, Zantac and Axid? About 2 years ago I reported to my internist that I was having heartburn daily. He prescribed Pepcid 20 mg twice a day. When over-the-counter Pepcid 10 mg came out, he allowed me to substitute two 10 mgs.

My concern is whether the use of these is altering the action of my gastric system. I know that stomach acid is necessary to aid in the digestive process, yet I am greatly limiting the production of acid. Can the digestive process continue efficiently without adequate stomach acid? Also, is the constant changing between Pepcid, Tagamet etc. detrimental? (Price has been a factor).

Some time after I started using Pepcid, I was diagnosed as lactose intolerant, with resultant cramps, bloating, gas and diarrhea. I was told to use Lactaid before ingesting dairy products, which seemed to be effective. Yet, sometimes I have the same symptoms without eating any dairy products.

Are there some dairy products such as yogurt, goat cheese or other cheeses that can be eaten without the need for a Lactaid-type product?

A:  The stomach secretes small amounts of hydrochloric acid (HCl, for those of you who remember chemistry class) even when empty, but this amount increases greatly when food is present. Acid not only aids in digestion (breakdown) of food, but also in absorption. Iron and some medications require the presence of some stomach acid to be absorbed properly.

The drugs you mentioned are all "histamine-2 receptor blockers," which decrease secretion of acid by about 50-80%, so you should still have plenty of acid left for digestion. Tagamet (cimetidine is the generic name) is metabolized in the liver and can interact with other medicines such as theophylline (for breathing), warfarin (for inhibiting blood clots), and phenytoin (for seizures). It probably should be used with great caution, if at all, by someone taking any of those medicines.

The newer ulcer drugs, Prevacid and Prilosec, are "proton pump inhibitors" which inhibit acid secretion by more than 90%. Nausea, constipation, flatulence and diarrhea have all been reported with these drugs. It is thought that the decreased acid levels allow for bacteria to multiply and accumulate, hence leading to the diarrhea.

Switching between these drugs is not harmful and may even help decrease symptoms. Some people might tolerate one drug better than the other; and as you have discovered, prices can vary widely and one drug may be more affordable, especially for those without the benefits of insurance.

People vary in their ability to tolerate lactose, or milk sugar. Many Asians and African Americans lack the enzyme needed for digestion of lactose. Some people only get a little gas from ice cream, while others will get almost instant diarrhea. You can buy the enzyme, lactase, in pill or liquid form. In any fermented cheese, be it goat or cow, the lactose is already broken down, so hard cheese should not cause symptoms. Yogurt, with live cultures, also doesn't contain lactose, but individual tolerance to yogurt or cheese may vary.

"Dear Doctor" is a compilation of patient questions answered by doctors from the Medical College of Wisconsin.