Science News - December 4, 2010

Topping the list of PPI drawbacks is the specter of bone fractures. Metz and colleagues reported in the Journal of the American Medical Association in 2006 that people who had been taking a PPI for more than a year had a 30 to 60 percent increased risk of hip fracture over those not taking acid blockers. A higher dose of PPIs boosted the risk to more than double. A Danish study, published the same year in Calcified Tissue International, also found that PPIs increased the risk of a broken hip by about half.

The U.S. Food and Drug Administration earlier this year slapped a fracture warning label on PPIs, both prescribed and over-the-counter, citing these and four other studies that showed an increase of fractures in people using the drugs.

While scientists are still sorting out how PPIs might affect bone, some theorize that acid is needed to dissolve calcium compounds, making calcium available in the blood and thus to the bone.

Another risk linked to PPIs is bacterial infection. Hospitalized patients getting a daily PPI are more likely to contract a Clostridium difficile bacterial infection than are people not taking any acid blockers, Harvard Medical School pulmonologist Michael Howell and colleagues reported in the May 10 Archives of Internal Medicine. Those getting the drugs more than once a day faced double

By Nathan Seppa
It’s
enough to
give you
HEARTBURN
Wonder drugs they may be, but PPIs are
overprescribed and pose some health risks

In the arms race against heartburn, one class of drug outperforms the competition by going straight to the source. The proton pump inhibitors, PPIs for short, block acid manufacture at the subcellular level. In contrast, acid reflux drugs such as Tums and Maalox neutralize the acid. Others, like Zantac and Tagamet, slow down its production by blocking the histamine 2-receptor. PPIs do require a day or two to start suppressing the symptoms of acid reflux. But once PPIs kick in, they put out the fire with stunning efficiency.

“No question about it. They are far more effective than anything we had before,” says Randolph Regal, a clinical pharmacist at the University of Michigan in Ann Arbor.

When PPIs first hit the market in the 1980s, the acid-blocking pills — sold as Nexium, Prilosec and Aciphex, among other brand names — looked like wonder drugs. Since then, U.S. sales of PPIs have grown to roughly $14 billion a year.

But PPIs now risk becoming a victim
of their own success. Several reports
indicate these drugs are overprescribed,
often in hospitals and to older patients.
And other studies suggest that long-term
use of the best-ever drugs for dousing
heartburn carries its own risks. PPIs have
accumulated a rap sheet linking them
to a heightened risk of broken bones,
bacterial infections and a few rare con-
ditions. Other research suggests that
weaning oneself off unnecessarily pre-
scribed PPIs can be difficult and can
cause, of all things, heartburn. These
potential drawbacks are forcing regula-
tors to rethink labeling on the drugs and
leading doctors to reevaluate prescribing
PPIs for some patients.

Unnecessary risk among other concerns, ppis have been linked to infection with the bacterium Clostridium difficile. in one hospital, a team identified 138 patients with C. difficile. of these, 88 were on a ppi, though only 34 had a clear medical reason for taking the reflux drug.