Medical Notes

Daily doses of Viagra may ease the pain of diabetes -- but not the way you might think. Animal studies hint that the male impotence drug reverses one of the worst miseries of diabetes: the stomach's refusal to empty after meals.

The problem affects as many as half of all diabetics and some three-fourths of those who have had diabetes for more than five years. Called gastroparesis, the occasional illness causes bloating, pain, appetite loss, and sometimes fits of vomiting. Currently, there is no effective long-term treatment in the U.S. -- especially since Propulsid, the most commonly used drug, has been withdrawn from the market due to safety concerns.

The new findings turn current thinking about gastroparesis inside out. "Maybe we have been thinking about it wrong," lead researcher Christopher D. Ferris, MD, PhD, tells WebMD. "They called it gastroparesis, which means 'stomach paralysis,' because they thought the stomach failed to squeeze stuff out. But now we know it is failure to relax -- we've kind of turned it around."

Ferris and co-workers at Johns Hopkins University in Baltimore discovered something unusual in the muscle that opens and closes the bottom of the stomach. Using laboratory mice with diseases that mimic human diabetes, they found that emptying food from the stomach depends on the ability of nerve cells in this muscle to process an important chemical. This same problem -- in a different muscle, of course -- afflicts men whose impotence can be relieved by Viagra.

When Ferris' team gave Viagra to the mice, it prevented the animals from developing stomach problems. Because gastroparesis in the mice was strikingly similar to gastroparesis in diabetic patients -- and because Viagra already is an approved drug -- Ferris says he will begin human studies also. Should these trials prove the treatment is safe -- a major question, as diabetics are prone to heart disease and Viagra can be dangerous in heart patients -- larger human studies will follow quickly. Such studies will be centered at Vanderbilt University in Nashville , Tenn. , with which Dr. Ferris now is affiliated.

Should Viagra prove safe and effective, its cost will be a major issue. Insurance companies already are complaining about supplying more than six of the popular blue pills each month. Diabetics would need at least one pill per day -- and those with severe cases would need three pills each day.

Ferris warns patients not to try this treatment at home until the studies can be completed. "I would caution consumers that any drug treatment is not without potential side effects," he says. "With Viagra, there is a particular concern for patients with heart disease, which is very common in diabetics. People need to be cautious that these studies have been done only in mice, not in humans. History is littered with things that work great in mice and then never pan out. Also, Viagra is expensive. To spend a lot of money on a drug that may not help is not wise."

Source:WebMD Health