Research Pipeline Bulging With Obesity Drugs

From the WebMD Archives

July 26, 2001 -- As Americans continue to pile on the pounds, researchers are working harder to produce a pill to help reverse the trend.

And while this effort has been marked with some setbacks, scientists may be getting closer to finding something that works.

More than half of all Americans are either overweight or obese. And even people who are a little overweight face increased risk for many diseases, including diabetes, heart disease, colon cancer, high blood pressure, and gallstones.

"Obesity is a time bomb to be defused," says George A. Bray, MD, a professor at Louisiana State University Medical Center in New Orleans. "We are on the verge of a major series of new drugs to help the problem." Bray spoke about obesity at a recent meeting of the American Medical Association.

Here's what's in the pipeline:

The drug that's farthest along in trials is leptin, also known as the fat hormone. Some research suggests that people who don't have this protein don't know when to stop eating. "Bray says that in ongoing studies of children who don't make leptin, the kids are being treated with the hormone are losing weight.

"In addition, research suggests that the drug Zyban -- when combined with a regular exercise program and a reduced-calorie diet -- helps people lose weight. It works by increasing the availability of certain brain chemicals that may play a role in curbing appetite. Zyban is currently used to help people quit smoking and, under the brand name Wellbutrin, to treat depression and anxiety.

A drug used to treat seizures, called Topimax, seems to help people lose weight as well, says Bray. Researchers observed that seizure patients taking the medication lost weight without changing their diet or exercise habits.

"We don't know why [Topimax works], but there is some thought that it enhances metabolic rate," says Denise Bruner, MD, president of the American Society of Bariatric Physicians and an obesity specialist in private practice in Arlington, Va.

There's also another drug in the works called CNTF. Researchers do not understand exactly how it works either, but it may act on nerve cells in a part of the brain -- called the hypothalamus -- that controls feelings of hunger and fullness. The drug's manufacturer is now raising money to proceed with further study, Bray says.

Bruner has had early success using certain diabetes drugs to treat obese people.

"We have been screening carefully for insulin resistance syndrome [a prediabetes state] and in doing so [we found] that a lot of people with high insulin are very hungry a lot of the time," she says. Giving them drugs that use up the insulin, such as Metformin and Avandia, makes them less hungry and better able to lose weight, says Bruner.

But there is no magic bullet pill for obesity, she tells WebMD.

"If a patient comes in and is unwilling to commit to physical activity and a meal plan, I will not depend on a pill," she says. "A pill is not going to be the answer."

However, she says, if people have been compliant but failed other treatments and are physically active, they would be a candidates for a drug to control appetite.