Two-thirds of Americans are overweight or obese, and for many, simple diet and exercise remedies don’t seem to work long term.

Doctors have been looking for a more effective medical treatment before turning to weight loss surgery, and Duke researchers believe they may have found an answer.

For many years, Mary Williams tried diet, exercise and even nutrition counseling to lose weight.

“Reducing on my own, I wasn’t successful at all,” she said.

Concerned about her high cholesterol, the 51-year-old joined a Duke study for the investigational drug Qnexa, a controlled release combination of two drugs, phentramine and topiramate.

“I was trying to go for 20 pounds, and I ended up doing 38,” Williams said.

All 2,500 participants received nutritional counseling. Those who took a placebo only lost an average of 3 pounds in a year.

“The higher dose of drug therapy achieved 22-pound weight loss, and even the lower dose achieved about 18-pound weight loss,” said Dr. Kishore Gadde, director of obesity trials at Duke.


Gadde says the treatment also significantly reduces blood pressure, blood sugar and triglycerides.

Last October, the U.S. Food and Drug Administration ruled that Qnexa could not be approved in its current form. They asked for more safety data because of side effect concerns. Now the manufacturer is expected to resubmit its application.

Gadde says Qnexa offered an average of up to 10 percent weight loss, whereas current drugs on the market only offer up to 3 percent.

“So there is a need for treatments that are more effective,” Gadde said.

Williams said the study drug is the only thing that’s worked for her.

“(It) really suppressed my appetite, gave me more energy,” she said.

(Read more about the weight loss study here.)

Reporter: Allen Mask, M.D.
Producer: Rick Armstrong
Web Editor: Kelly Hinchcliffe

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