Drug Combination May Help Reduce Weight

Dec.18 -- The author of a new diet book defended his new drug combination therapy against criticism that he has yet to prove that it is safe, or that it works in a published scientific study.

Dr. Paul Rivas, an obesity specialist and author of the new book Turn Off the Hunger Switch, believes the combination of phentermine and antidepressants such as Zoloft and Prozac effects brain chemistry to promote weight loss.

"I've tried it now on over 8,000 people, probably close to 10,000 over the last eight years," said Dr. Rivas in an interview today on Good Morning America.

Rivas claims that it would be very difficult to do a study on this combination of drugs. "The reason that is is because we customize every patient, so we don't have a standardized approach that you could study," said Rivas.

Dr. Timothy Johnson, ABCNews' medical editor, disagreed with Rivas' claims during the GMA segment. "The unwritten rule was if you do not publish you should not promote, and I still believe that's the way to go," said Johnson. "I'm always concerned when you combine things, and I disagree respectfully that you can't study certain [combinations]. If you're going to start using something on a wide scale, and promote it to the public, I think you can study it in various ways and should."

Drugs as ‘Future of Treatment’ for Obesity

On its own, Phentermine has been shown to suppress the appetite, and the antidepressants function to overcome deficiencies of brain chemicals that affect mood.

Rivas believes such chemical imbalances are the cause of obesity in many people, and that antidepressants can help return chemicals levels to normal.

Dr. Richard Atkinson, professor of medicine at the University of Wisconsin in Madison and the president of the American Obesity Association, says he also prescribes the phen-antidepressant drug combination to his obese patients, but notes the combination has yet to be proven more effective for weight loss than phentermine alone.