An experimental weight-loss drug that combines two older medications helped people drop pounds without suffering severe side effects, according to a report on a large, year-long clinical trial published online Sunday in the medical journal Lancet.
About 70 percent of U.S. adults are overweight; of those, 34 percent are obese. Despite epidemic rates of obesity and type 2 diabetes, there are still few options for men and women who need help to lose weight and keep it off. Federal officials, while acknowledging the need for weight-loss drugs, have rejected several new diet pills in the past year, citing concerns about possible long-term risks in this new generation of meds meant to be taken not for a few weeks but for months or even years.
This trial, involving 2,487 overweight and obese men and women, tested the effects of very low doses of phentermine, an appetite suppressant used for weight loss since the 1960s, with moderate doses of topiramate, a medicine prescribed to prevent seizures and migraines first approved by the U.S. Food and Drug Administration (FDA) in 1996 under the brand name Topamax. The combo was tested in two different doses and compared with a placebo. All the patients — who ranged in age from 18 to 70 — got counseling on lifestyle and dietary changes. The men and women had a body mass index of 27 (about 160 pounds for a 5-foot-5-inch person) to 45 (270 pounds for a 5-foot-5-inch person).
On the lowest dose of the combination drug, the majority of people — 62 percent — lost at least 5 percent of their body weight and sustained that weight loss over the course of a year. More than a third lost at least 10 percent of their body mass. The average weight loss for this low-dose group was about 18 pounds. A second, slightly higher dose produced even greater average weight loss — 22 pounds — while the placebo regimen yielded an average loss of only 3 pounds.
People who took the combination drug also enjoyed improvements in blood pressure, cholesterol and blood sugar.
Indeed, the contribution of this study was not so much in proving that the drugs promote weight loss — a well-known benefit in both cases — but that combining the drugs in low doses seems to result in fewer side effects while still helping patients drop excess pounds. The researchers said the combination of the two drugs along with changes in lifestyle "might be a valuable treatment for obesity that can be provided by family doctors."