June 2 (HealthDay News) -- Powerful and widely used antacids called proton pump inhibitors and histamine-2 receptor antagonists relieve stomach acid, but also appear to increase the risk of hip and thigh fractures, a new study confirms.
This new report, when coupled with findings from several other studies, supports the idea that these drugs increase the risk of bone breaks. Common proton pump inhibitors include Prilosec, Prevacid and Nexium, while common histamine-2 receptor antagonists include Pepcid, Tagamet and Zantac. These drugs are typically used to treat gastroesophageal reflux disease (GERD).
"The medicines may increase the risk of fracture," said study author Dr. Douglas A. Corley, a gastroenterologist at Kaiser Permanente in San Francisco. "People should only take the medications for a defined indication and should take them at the minimal effective dose," he added.
"The next step is evaluating whether taking calcium or vitamin D actually changes the risk, because we don't know for sure what the mechanism is," he said. "The main thing right now is to be aware that there is this association."
Stomach acid is there for a reason, Corley said. "Completely eliminating it may have adverse effects. People are at an increased risk of getting food-borne infections when they are on these drugs, and this [fracture risk] is something else that may be at increased risk as well," he said.
The findings were presented Monday in Chicago at the Digestive Disease Week 2009 meeting.
For the study, Corley collected data on 33,752 people taking these medications and 130,471 people who were not taking them. People who had hip fractures were 30 percent more likely to be taking proton pump inhibitors over two years, he found.
In addition, people with hip fractures were 18 percent more likely to have had a fracture if they were taking histamine-2 receptor antagonists, Corley found.
People taking less than one pill a day had a 12 percent increased risk of fracture, while people taking the average dose of one pill a day had a 30 percent increased risk, Corley noted. For those taking more than one pill a day, the increased risk was 41 percent.
People aged 50 to 59 who had been taking these medications for two years or more had the greatest risk, but most of the fractures were seen in people between 80 and 89, Corley said.
Although the reason for the association isn't known, a small study did find that proton pump inhibitors reduced the body's ability to absorb calcium, necessary for bone strength, by 60 percent, he added.
Corley noted that when people stopped taking these drugs, their risk for fractures dropped.
Dr. Elton Strauss, chief of Orthopaedic Trauma and Adult Reconstruction at Mount Sinai School of Medicine in New York City, said this association has been noted before, but it boils down to a question of a small risk versus a benefit for patients who need these medications.
Just last August, a Canadian study found that long-term use of proton pump inhibitors quadrupled the risk of a hip fractures.
"This has been discussed previously," Strauss said. "This is a small sample of the population, one that has so many risk factors for falls and fractures."
Strauss stated: "The key to this article is awareness for both the physician prescribing the meds and the patient taking them. It is the classic problem in medicine of risks versus benefits."
SOURCES: Douglas A. Corley, M.D., gastroenterologist, Kaiser Permanente, San Francisco; Elton Strauss, M.D., associate professor, chief of Orthopaedic Trauma and Adult Reconstruction, Mount Sinai School of Medicine, New York City; June 1, 2009, presentation, Digestive Disease Week meeting, Chicago