April 10th, 2011
06:30 PM ET
Two existing drugs, in combination, have shown significant promise in promoting weight loss, according to a new report.
The drugs, phentermine and Topamax, in combination with lifestyle and weight-loss counseling were associated with a 18-22 pound weight loss in trial participants, compared with a three-pound weight loss in patients who received counseling alone.
By comparison, the only approved long-term prescription weight loss medication available on the market today, Xenical, is associated with a seven-pound weight loss when combined with diet and exercise.
The study was funded by the pharmaceutical company Vivus, which combined the two drugs into one pill called Qnexa, and petitioned the U.S. Food and Drug Administration for approval in October 2010. The Food and Drug Administration denied the request, asking for more safety data from the company before moving forward.
According to the report, there were specific concerns about each drug's safety individually; specifically Topamax, which is reported to cause some psychiatric and cognitive side effects and may cause clef palate birth defects if taken while pregnant.
According to the manufacturer's study, the two drugs, when taken together, and at controlled-release doses, were very safe. Participants in the trial reported minor side effects such as dry mouth and constipation, however at higher doses, some participants did complain about some psychiatric side effects.
Among the 2,487 study participants, nine became pregnant, and none of their children were born with cleft palates, the report said.
The drug could be a good option for some people, but it's most likely not a silver bullet, said Dr. Melina Jampolis, CNNHealth's physician nutrition expert, who is not connected with the study.
"This might be a good tool in the short term to get someone motivated, and that's great," she said. "But unless it's paired with aggressive lifestyle changes, it may not be great in the long term."
Phentermine is commonly used as a short-term weight loss treatment, and was previously paired with fenfluramine to make the successful but now-discontinued weight loss drug Fen-phen. Fen-phen was removed from the market in 1997 amid concerns about the drug's heart risk, but phentermine has been used successfully for short-term appetite suppression since then with no major safety concerns.
Topamax is commonly used to treat migraines and seizures.
From around the web
About this blog
Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.