New Hope for Diet Drugs

New Hope for Diet Drugs2010 has not been a good year for diet drugs. In July, a promising new weight loss drug, Qnexa, was rejected 10 to 6 by an FDA review panel. Then in October, the FDA asked Abbott laboratories to withdraw voluntarily its weight loss drug Meridia because of concerns about possible side effects.

But things may be looking up. An FDA advisory committee recommended approval of a new weight loss drug called Contrave.

What is Contrave? Contrave is a combination of two drugs already approved for other conditions - Bupropion (commonly known as Wellbutrin and Zyban) and Naltrexone.  Wellbutrin is an antidepressant well known to help people lose weight. The problem is the effects don't last - and neither does the weight loss. Naltrexone is a drug that patients take to overcome addictions to alcohol and drugs. The Naltrexone seems to help increase calorie burning and keeps the Wellbutrin working.

How well does it work? Researchers tested the drug in a large clinical trial of almost 700 people. The average starting weight of the participants was 223 pounds. Everyone in the study enrolled in an intensive weight loss program that included counseling, exercise, and diet. Two thirds of the participants took the diet drug and the rest took a placebo (sugar pill). After over a year in the program, everyone lost weight - an average of 11 to 16 pounds. But the people who took the Contrave lost an average of 20 to 25 pounds.  

Contrave and Weight Loss after 1 year:

  • Overall weight loss in the program: 11 to 16 pounds
  • People on Contrave: 20 to 25 pounds

The people taking the Contrave also reported a better quality of life than the placebo group. But the big message here is that these drugs assist people in their efforts to lose weight. The people in the study still had to work hard at healthy habits to lose weight.

Some of the people on the Contrave had some side effects but they happened early on in the study:

Possible Side Effects of Contrave:

  • Nausea
  • Headaches
  • Constipation

The drug company Orexigen makes Contrave. The company is also testing another weight loss drug called Empatic.

The final word about approval won't come until after the New Year. Its approval may signal a shift in philosophy at the FDA - a philosophy that it more open to approving weight loss drugs despite the small but significant chances of serious side effects. The FDA has asked Orexigen to continue safety studies even if it approves Contrave. This will offer hope the makers of Qnexa whom the FDA also asked for more data before approval. 

Beth Kitchin, MS, RD
Assistant Professor
Department of Nutrition Sciences
University of Alabama at Birmingham