An estimated 15 million Americans suffer from heartburn every day, but not everyone needs to take a proton pump inhibitor (PPI) drug. PPIs are a class of very effective and generally safe medicines used to treat heartburn, gastroesophageal reflux disease (GERD), and gastric ulcers, but they can carry serious risks.

PPIs have been heavily promoted, which has led to overuse in people with garden-variety heartburn who do not need one of these medications. Nexium, one of the most widely-prescribed PPIs, is also the most expensive at $248 per month (the cash price you would pay if your insurance did not cover it) for a 20 mg dose. Not surprisingly, Nexium was also a top-selling drug in 2009, racking up sales of $6.3 billion, according to IMS Health.

So before you turn to a PPI, make sure you really need it. If you have occasional, mild heartburn and have not been diagnosed with gastroesophageal reflux disease (GERD), you should first try lifestyle changes, like reducing how much alcohol and caffeine you drink, quitting smoking, eating smaller meals and losing weight if you need to. If those don't work, try an inexpensive over-the-counter antacid, such as Maalox, Mylanta, Rolaids, Tums, or their generic equivalent, or drugs called H2 blockers, which include Pepcid AC, Zantac 150, or their generic equivalent.

But if you suffer from heartburn twice a week or more for weeks or months on end, you should see a doctor because you may have GERD, also known as acid reflux, a serious condition that can inflame or erode the lining of the esophagus. PPIs are effective at treating GERD, but you will have to see a doctor to confirm you have the condition and monitor your treatment to make sure it's effective.

So here's the good news: The latest Consumer Reports Health Best Buy Drugs analysis of drugs to treat heartburn, GERD and gastric ulcers finds that among the seven available PPI drugs, no drug works better than another and all are relatively safe. Three—omeprazole (Prilosec, Prilosec OTC), lansoprazole (Prevacid, Prevacid 24HR), and omeprazole/sodium bicarbonate (Zegerid, Zegerid OTC)—are available as a prescription and a nonprescription drug. Two—omeprazole and pantoprazole (Protonix)—are available as a brand-name drug and a generic, which contains the same active ingredient but costs significantly less.

(See links above to download the full PDF report or a 2-page summary report.)

Taking the evidence for effectiveness, safety, cost, and other factors into account, if you need a PPI, we have chosen the following as Consumer Reports Health Best Buy Drugs:

• Generic omeprazole OTC
• Prilosec OTC
• Prevacid 24HR

All three of these drugs are available without a prescription. You could save about $200 a month or more by choosing one of these medicines over more expensive prescription PPIs. If you have health insurance, find out if your plan will help pay for generic omeprazole OTC, Prilosec OTC, or Prevacid 24HR. If not, talk with your doctor about taking the PPI with the lowest out-of-pocket cost to you.

Safety notes: Several studies have linked PPIs to a higher risk of pneumonia and infection with a bacterium called Clostridium difficile, and other studies have found that long-term use of PPIs may be associated with an increased risk of certain bone fractures. Talk with your doctor about those risks, especially if you must take a PPI over a long period of time. People ages 65 and over and those with chronic medical conditions should be vaccinated against pneumonia and get a flu shot every year and we emphasize this recommendation for people in those categories who are also taking a PPI.

In addition, anyone taking clopidogrel (Plavix), a blood thinner used to prevent clots after heart attacks and stent placement, should be especially cautious with PPIs. Some studies indicate that PPIs may reduce clopidogrel's effectiveness, which could increase the risk of another heart attack. Our medical advisers recommend that people taking clopidogrel should not take PPIs unless other remedies have not been adequate.

This report was last updated in May 2010.