I have been suffering from GERD for years. I had been on Prevacid and am now back to Prilosec. Recently, my gastroenterologist gave me samples of Domperidone -- 10mg. He says it's not approved by the FDA and is only available in Canada, Belgium and Mexico. Do you know anything about this drug? What are its side effects?

J.B.

Gastroesophageal reflux disease (GERD) is a common disorder that can cause heartburn. It is caused by a reflux of stomach acid into the esophagus because the sphincter that separates the esophagus and stomach is too lax to keep the stomach acid in its place. The medications commonly used to treat GERD include acid-suppressive medications, such as the proton-pump inhibitors (PPIs). The PPIs, which include lansoprazole (Prevacid) and omeprazole (Prilosec), are the most potent acid-inhibitors available. Also, a new PPI called rabeprazole (Aciphex) was recently released.

Most patients respond well to PPI therapy. However, some people suffering from very severe reflux require additional therapy. Until recently, Propulsid (cisapride) was frequently used as a second-line medication for reflux. Propulsid works by enhancing the normal muscle function of the esophagus and stomach, helping to clear the esophagus of acid and the stomach of its contents. It also increases the pressure in the gastroesophageal sphincter, thus decreasing the chances for reflux to occur. However, because certain patients taking Propulsid developed abnormal heart rhythms, the drug's manufacturer decided to remove it from the market in July 2000. (For more information, see the article Substitutes for Propulsid?) Another drug that has similar effects in the esophagus and stomach is metoclopramide (Reglan). However, this medication can lead to neurological side effects of sedation, restlessness and, in rare cases, movement disorders like Parkinson's disease.

Domperidone is a drug that is similar in function to metoclopramide. It has much less effect on the brain, and thus causes fewer side effects. It is commonly used in Europe for treating GERD and other disorders of abnormal muscle function of the stomach. The usual dosage is 10-20mg, given three to four times a day.

Most gastroenterologists feel domperidone is a potentially excellent drug in the treatment of GERD, especially for patients in whom PPIs are inadequate. However, the U.S. Food and Drug Administration has not yet approved this medication. Thus, it is virtually impossible to obtain this medication in the United States. If you are able to obtain domperidone, you should inform your doctor that you are planning to use it and receive close follow-up.