Comparing Proton Pump Inhibitors

Recent research backs up the effectiveness of a class of drugs frequently prescribed for people with frequent, persistent heartburn. The study showed that so-called proton pump inhibitors work well in decreasing the amount of acid produced in the stomach. And, among the five types of PPIs, one performed better than the rest.

The findings are important for suffers of gastroesophageal reflux disease, or GERD, a condition in which stomach acid backs up the esophagus, causing symptoms such as heartburn and regurgitation. The idea is that if a drug can suppress acid production, then the potential for esophageal injury and severe reflux is also diminished. "The solution is elegantly simple," says study co-author Dr. Philip Katz, chairperson of the division of gastroenterology at the Albert Einstein Medical Center in Philadelphia.

The study, published in the December 2003 issue of the American Journal of Gastroenterology, examined the effects of PPIs on patients who suffered from erosive esophagitis. That's a complication of GERD in which the lining of the esophagus, the food pipe that connects the mouth to the stomach, becomes inflamed. Researchers looked at the ability of five PPI medications — esomeprazole (marketed under the name Nexium), rabeprazole (Aciphex), omeprazole (Prilosec), lansoprazole (Prevacid) and pantoprazole (Protonics) — to decrease the amount of acid present in the stomach at the dosages approved by the Food and Drug Administration. "None of these drugs had ever been compared head to head, and now we have that data," says lead author Dr. Philip Miner, president and medical director of the Oklahoma Foundation for Digestive Research.

Over the course of approximately 11 weeks, 34 patients with GERD sampled each drug for five days at a time. Their stomach pH levels were measured after each sampling period. "We measured the number of hours in a day where the pH stayed above a 4 (the critical point at which there's little or no acid)," says Dr. Mark Sostek, senior director of clinical research for AstraZeneca, the maker of Nexium and funder of the study.

Doctors found that on the fifth day of each cycle, esomeprazole kept pH levels above the magic number "4" for 14 hours. Relief with rabeprazole lasted 12.1 hours; omeprazole for 11.8 hours; lansoprazole for 11.5 hours; and pantoprazole for 10.1 hours. Esomeprazole was 4 percent to 9 percent more effective in healing all GERD sufferers; and10 percent to 13 percent more effective for patients with erosive esophagitis.

The lowdown on PPIs
Before PPIs came to the market in the 1990s, physicians relied on either antacids (such as Rolaids) or H2 blockers (such as Tagamet or Pepcid) to treat GERD. Antacids work quickly but wear off quickly, says Sostek. H2 blockers, meanwhile, attack just one of a number of mechanisms used by the cells to make acid and their benefits linger only for 4 to 6 hours. Patients who use them for longer than six months may also develop a tolerance for the drug, says Dr. Bennett Roth, chief of clinical gastroenterology at the David Geffen School of Medicine at UCLA. PPIs, which inhibit acid production in its final stages, brought the promise of longer lasting respite. "PPIs are by far the most effective drugs for severe acid reflux," says Roth, who was not affiliated with the study.

In the future, however, PPIs may be overshadowed by medications now in the works that address a physiological problem often found in GERD patients: a malfunctioning lower esophageal sphincter. The LES acts as a gate between the esophagus and the stomach; when it relaxes, acid escapes. The new drugs, which are still in the development stage, aim to reduce the frequency of the relaxation. "You'd be treating the problem more directly [with them]," says Roth.

So should patients switch to esomeprazole immediately? Not necessarily, says Katz. "If what you're on is working and you're happy, there's no need to switch," he says. In fact, experts say consumers can't go wrong with any of the PPIs; and much depends on the particulars of a case. "In my practice, I do prescribe all five," Miner says.

Republished with permission from MSNBC.com