Antidepressant Doubles Weight Loss in Obese-Study

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Antidepressant Doubles Weight Loss in Obese-Study

Mon Feb 25, 4:49 PM ET

By Deena Beasley

LOS ANGELES (Reuters) - The antidepressant Wellbutrin helps obese people

who are dieting and exercising lose twice as much weight as those who

only change their lifestyle, according to a study released on Monday.

Researchers conducted a nearly year-long clinical trial of 327 men and

women who were 30 percent to 100 percent above their ideal body weight,

but were not depressed. Britain's GlaxoKline Plc makes Wellbutrin,

known generically as bupropion, and funded the study.

" Obesity is a difficult problem, and it is on the increase, " said Dr.

, professor of medicine and clinical nutrition at the

University of Kentucky, Lexington.

" Diet and exercise are mainstays ..., but we need additional arrows in

our quiver, " said , who presented the study at a conference in

San Diego.

The study compared weight changes in patients receiving the drug at two

different doses with those getting placebo for 24 weeks, followed by a

look at whether the weight loss was maintained after another 24 weeks.

All of the participants undertook a moderate exercise program and a diet

that had 600 fewer calories per day than needed to maintain their

weight. They also kept daily diaries of food intake and physical

activity, and made visits to a clinic where lifestyle goals were

reinforced.

In the first 24 weeks, participants assigned to the higher dose of

Wellbutrin lost an average of 10.1 percent of their original body

weight, compared with 7.2 percent for those on the lower dose and 5

percent for the placebo group.

After the full 48 weeks, patients on the high dose showed an average

loss of 8.6 percent of starting body weight, compared with 7.5 percent

for those on the lower dose. The study did not measure weight loss

maintenance in the placebo group because those patients were told ahead

of time that they would be given the drug after six months.

" It was an incentive to get people to enroll in the trial, " said.

Those patients who were initially on the placebo lost an average of 7.2

percent of their weight at the higher drug dose and 6.4 percent at the

lower dose by the end of the study.

DRUG TARGETS BRAIN CHEMICAL DOPAMINE

said that compared with the placebo group, the Wellbutrin

patients experienced more headaches, dry mouths and diarrhea -- side

effects commonly seen with the drug when it is used to treat depression.

Wellbutrin is a dopamine-targeting antidepressant, unlike some other

drugs like Prozac or Paxil, which combat depression by coaxing

serotonin, another brain-messenger chemical, to remain in spaces

surrounding nerve endings.

" We don't understand how Wellbutrin works, " said. " It enhances

production of norepiphrine and dopamine, which are both involved in

appetite. "

Glaxo, which also sells the drug under the brand name Zyban as an aid to

smokers trying to quit, has no current plans for further weight loss

studies and is still evaluating whether to pursue regulatory approval

for treating obesity, spokeswoman Holly said. The company's

patent on the drug expires in 2013.

said Wellbutrin, shown here to boost weight loss by about 5

percent, may work slightly better than the other major obesity drugs --

Abbott Laboratories' Meridia and Roche Holdings AG's Xenical, which help

shave an extra 3 percent to 4 percent and 4 percent to 5 percent,

respectively, from the scale.

He said side effects of these drugs can also be a problem. Xenical,

which works by preventing the body from fully absorbing fat, can cause

diarrhea after a high-fat meal, while Meridia, a next-generation

appetite suppressant, can cause a slight increase in heart rate and

blood pressure.

Some doctors are trying phentermine, half of the controversial

weight-loss combination fen-phen, in combination with antidepressants

like Paxil, which target serotonin, as a weight-loss treatment, but

there have been no clinical studies of the combination therapy.

The fen-phen cocktail was linked to serious heart-valve problems and the

fenfluramine half, which was implicated as the troublemaker, was pulled

from the market. Phentermine continues to be used as an appetite

suppressant.