No Serious Side Effects Seen
The most common side effects were nausea, headache, and dizziness. Each of the two drugs, when used separately, increases risk of certain psychiatric problems, but this was not seen with the combination pill. In addition, the two drugs, when taken as separate pills, also increase blood pressure.
Blood pressure did not decrease as much as would be expected with the 5% weight loss among people taking Contrave, and those in the placebo group saw sharper blood pressure reductions with just diet and exercise.
What's more, there were no changes seen in levels of LDL or "bad" cholesterol levels among those who took the experimental obesity drug. There were some improvements in other heart disease risk factors such as blood fats known as triglycerides, HDL or "good" cholesterol levels, insulin resistance, and C-reactive protein, a marker of inflammation.
"The reassuring thing about the side effects is that both of these drugs have been in wide use for over 20 years and no side effects were seen that were not expected from the experience with the individual drugs," Greenway says. "Bupropion-naltrexone improved insulin resistance [and] insulin resistance leads to diabetes and is associated with the cardiovascular risk factors associated with obesity."
In an accompanying editorial, Arne Astrup, MD, head of the department of nutrition at the University of Copenhagen, writes that "more data are needed to get a better overall assessment of cardiovascular risks of this otherwise promising combination therapy for obesity."
More Weight Loss Pills Needed
Combination pills represent the future of obesity treatment, says Louis Aronne, MD, director of the Comprehensive Weight Control Program at New York-Presbyterian Hospital/Weill Cornell Medical Center in New York City.
"Using medications and combination medications in conjunction with changes to diet and exercise can get us the results we are looking for in terms of reductions in body weight and obesity-related comorbidities," he says.
These medications are useful for people in whom diet and exercise alone is not enough but are not candidates for weight loss surgery, he says.
The more drugs available to treat obesity, the better, he says. It's not a one-size-fits-all situation.