TUESDAY, Dec. 7 (HealthDay News) -- An expert advisory panel recommended on Tuesday that Contrave, a new weight-loss pill that combines an antidepressant with an anti-addiction medication, be approved by the U.S. Food and Drug Administration.

The 13-7 vote in favor of Contrave came amid agency concerns that the drug might raise blood pressure in some patients and increase the risk of heart attacks and strokes among some users, according to the Associated Press. But panelists voted 11-8 earlier in the day that those potential health risks could be studied after Contrave was approved.

The FDA does not have to follow the advice of its advisory committees, but it typically does. The agency is expected to make a decision on Contrave by Jan. 31, the wire service reported.

Contrave is manufactured by Orexigen Therapeutics Inc. In October, the FDA voted against approving two other weight-loss drugs, Arena Pharmaceuticals' lorcaserin and Vivus' Qnexa, because of safety concerns, according to the AP.

Last July, a study funded by Orexigen and published in The Lancet found that Contrave helped users shed pounds when taken along with a healthy diet and exercise.

People who took the drug for more than a year lost an average of 5 percent or more of body weight, depending on the dose used, the team said.

However, the regimen did come with side effects, and about half of study participants dropped out before completing a year of treatment.

Contrave is combination of two well-known drugs, naltrexone (Revia, used to fight addictions) and the antidepressant bupropion (known by a number of names, including Wellbutrin). The drug appears to boost weight loss by changing the workings of the body's central nervous system, the researchers said.

The study enrolled men (15 percent) and women (85 percent) from around the country, ranging in age from 18 to 65. They were all either obese or overweightm, with high blood fat levels or high blood pressure.

The participants were told to eat less and exercise, and they were randomly assigned to take a twice-daily placebo or a combination of the two drugs at one of two levels.

After 56 weeks, only about half (870) of the more than 1,700 participants initially enrolled remained in the study. Almost half (48 percent) of those who took the highest dose of naltrexone lost 5 percent of their weight or more, while only 16 percent of those who took placebos did.

However, about 30 percent of those taking Contrave experienced nausea, the study authors say, and other side effects included headache, constipation, dizziness, vomiting and dry mouth.

Still, Contrave may give people struggling to lose weight a new option, the researchers contended.

The Lancet findings echo those of studies into other diet drugs such as Meridia, Xenical and Alli, said Lona Sandon, an assistant professor of clinical nutrition at the University of Texas Southwestern Medical Center in Dallas and spokeswoman for the American Dietetic Association.

"When these are combined with a modestly reduced calorie diet, modest amounts of weight loss are achieved," she said. "One striking thing to note is the study drop-out rate of 50 percent. This may have been due to side effects of medications, the fact that it is hard to stick to dietary changes for 56 weeks, or [the fact that] slow and only modest weight loss did not meet participant expectations."

Cynthia Sass, a New York City-based nutritionist and author, added that drugs used to treat addiction also appear to help with weight control, supporting "the notion that food can be addictive for many people."

An accompanying Lancet editorial noted that one concern is that blood pressure did not drop as much as expected in the higher weight-loss group. "More data are needed to get a better overall assessment of cardiovascular risk of this otherwise promising combination therapy for obesity," wrote Professor Arne Astrup, a nutrition expert at the University of Copenhagen, Denmark.

More information

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