Orexigen’s two-drug obesity pill promising

Patients taking Contrave reportedly felt fuller and had fewer food cravings. Their desire for sweet and starchy foods also plunged, the researchers said.

Drug pharmacology
Contrave is a combination of two drugs – naltrexone, an anti-addiction drug used to alcoholism and other addictions, and bupropion, an antidepressant.

Targeting two different parts of the brain, naltrexone will influence appetite and the bupropion will control cravings and rewards, said Frank Greenway, the lead author of the study.

"This is first obesity drug I’m aware of that appears to have a significant effect on the reward system and it represents something new and unique that will address issues some people have that may not have been addressed in the past," Greenway said.

The study
Nearly 1,700 overweight or obese volunteers with a BMI of 27 to 45 took part in the trial. Participants were randomly divided into three groups –taking fixed dose of bupropion with either a higher dose or lower dose of naltrexone, or placebo.

All participants were prescribed a reduced-calorie diet and exercise.

"This is first obesity drug I’m aware of that appears to have a significant effect on the reward system and it represents something new and unique that will address issues some people have that may not have been addressed in the past." -- Frank Greenway, the lead author of the study

Not all the patients completed the 56-week trial; reportedly, half dropped out for various reasons.

Findings of the study
Patients taking the high-dose combination of Contrave shed, on average, 13.4 pounds, about 6.1 percent of their body weight, as against an average weight loss of 10.8 pounds, or 5 percent of body weight in lower-dose group.

Participants taking placebo lost 3.1 pounds, or 1.3 percent of their body weight, researchers said.

Side-effects
The drug reportedly scored safe. The side-effects from the drug were mild and went away with time, Greenway said.

Nausea was reportedly the most common side-effect. Thirty percent of the high-dose group and 27 percent of the lower-dose group experienced it. Headaches and constipation were also experienced by more than 14 percent of those taking two formulations of Contrave against a placebo.

The drug also resulted in a slight rise in blood pressure in the first month of study. The blood pressure then dropped slightly for the remainder of the trail, researchers say.

The findings of the trial are published today in the journal Lancet.