TUESDAY, Nov. 25, 2014 (HealthDay News) -- Heartburn drugs such as Prilosec and Nexium may disrupt the makeup of bacteria in the digestive system, potentially boosting the risk of infections and other problems, a small new study suggests.
The research doesn't confirm that these changes make it more likely users will become ill, and study authors aren't recommending that anyone stop taking the so-called proton pump inhibitors.
However, these antacids "should be used at the lowest dose that provides adequate relief of symptoms, and attempts to discontinue their use should be considered periodically," said study co-author Dr. John DiBaise, professor of medicine at the Mayo Clinic in Scottsdale, Ariz.
According to Harvard Medical School, billions of dollars are spent annually on antacid drugs in an attempt to combat heartburn, ulcers and gastroesophageal reflux disease, also known as GERD. Old standbys such as Maalox and Mylanta have been supplanted by more effective, more expensive drugs, including proton pump inhibitors. These include Prevacid (lansoprazole) and Protonix (pantoprazole) in addition to Prilosec (omeprazole) and Nexium (esomeprazole).
"Despite years of safe and effective use, in recent years there have been an increasing number of reports suggesting potentially harmful effects and harmful associations with their use," DiBaise said.
Long-term use of proton pump inhibitors has been linked to infection with a germ called Clostridium difficile, which causes severe diarrhea, he said. Researchers have also connected the medications to vitamin deficiencies, bone fractures and pneumonia, among other conditions.
In the new study, researchers sought to understand what happens to the trillions of germs in the digestive system when people take omeprazole, the generic name for the drug best known as Prilosec.
Ten participants, aged 18 to 57, took 20 or 40 milligrams of the drug a day for 28 days. Researchers analyzed the study participants' stool samples to understand the germs in their guts.
"These microbes have evolved with us to participate in our normal development and metabolism, and perform certain functions that we would not be able to accomplish without their help," DiBaise said. Many scientists believe that people's risk of disease goes up when their normal germ makeup changes, he said.
The researchers found evidence that the medications disrupted the balance of bacteria in the digestive systems of the participants, and the changes lasted for at least a month after they discontinued the drug. It didn't seem to matter whether they took the higher or lower dose, DiBaise said.
DiBaise cautioned that the study doesn't prove that the drug causes users to become more vulnerable to C. difficile infections. However, it shows that the drug "creates a situation in the gut microbial environment that may increase an individual's susceptibility," he said.
The researchers suggest additional research is needed with a larger group of study participants.
What should users do for now? According to DiBaise, proton pump inhibitors are "the most effective medications to treat gastroesophageal reflux disease." If patients don't have the most severe symptoms, he said, other types of heartburn drugs might help. Also recommended: eating smaller portions, losing weight, not lying down for two hours after eating, and avoiding alcohol, cigarettes and "trigger" foods.
Dr. David Johnson, chief of gastroenterology at Eastern Virginia Medical School, said patients shouldn't become alarmed about "the safest class of therapy I've used in the 34 years being a doctor."
The new research won't stop him from prescribing the drugs, Johnson said, adding he's "hesitant to make too much out of this." Even so, "the key message is that patients should talk to their care provider and discuss the need for these medications and justify their continued use."
The study was published Nov. 24 in the journal Microbiome.
For more about proton pump inhibitors, visit the U.S. National Library of Medicine.