Combo Treatment Causes Significant Weight Loss

New Rx treatment for obesity

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Losing weight is difficult, and for some people, exercise and good nutrition isn't enough. According to a new study, a new combination drug that’s currently being tested could help obese people drop those extra pounds.

A team of scientists combined two types of drug on weight loss: phentermine, a fast-acting appetite-suppressing drug that’s used for a short period of time, and topiramate, a sustained-release anti-seizure drug that’s being tested for its ability to induce a sense of satiety when combined with phentermine.

The team gave combinations of the drugs to overweight and obese patients, and found that patients who took combined treatment lost significantly more weight, compared to placebo-taking patients.

"Combo drug pending FDA approval can help treat obesity."

In the study, researchers from Karolinska Institutet in Stockholm, Sweden, the University of Alberta in Edmonton, Canada, and colleagues gave 2,487 patients one of three treatments: a placebo, a medium dose of the two the drugs and a higher dose of the two drugs.

The medium dose contained 7.5 mg of phentermine and 46 mg of topiramate. The higher dose had 15 mg of phentermine and 92 mg of topiramate. The patients received treatment for 56 weeks.

The researchers divided the subjects into groups based on whether the patient had another illness that may coincide with obesity.

The groups included those who have “weight related subclinical risk factors,” which include minor pain and slight psychological problems (group 1); those who have weight-related chronic disease (group 2); and those with established end organ damage (group 3).

All obese patients benefited from the combo drug treatment, said lead study author Dr. Stephan Rossner of the Karolinska Institutet in an interview.

Additionally, the team found that having weight-related health problems made no difference in the amount of weight a patient lost, as both combo-drug-taking groups dropped a similar amount of weight.

They found that patients taking the medium dose of combo drugs reduced their body mass index (BMI) by 7.3% (group 1), 8.6% (group 2) and 6.8% (group 3). In the higher dose group, patients reduced their BMI by 10% (group 1), 10.5% (group 2) and 9.5% (group 3). Meanwhile, those in the placebo group reduced their BMI by just 1.5% (group 1), 1.8% (group 2) and 2.3% (group 3).

Rossner says that side effects from the combo drugs are modest, and include dry mouth, constipation and tingling, burning, pricking or numbness of the skin.

Obesity is a common, growing problem in the U.S. affecting more than one-third of the population.

Earlier this year, The Food and Drug Administration (FDA) Advisory Panel recommended that the FDA approve the phentermine/topiramate drug combination for the treatment of obesity.

The drug is slated to be called Qvisa in Europe. The FDA will make its decision on the drug’s approval on July 17.

The study was presented May 8 at the 19th European Congress on Obesity in Lyon, France. The research was funded by VIVUS, Inc., the manufacturer of Qvisa.

The study has not yet been published in a peer-reviewed journal, which means other scientists may not have had a chance to review the methods and data to ensure it passes their quality standards.

Reviewed by: 
Review Date: 
May 13, 2012
Last Updated:
August 1, 2012