The FDA has recently given approval to Contrave, a new drug that combines two generic drugs, naltrexone and bupropion, to aid weight loss. Naltrexone is typically used to treat addiction to alcohol or narcotics, while bupropion is used to treat depression, seasonal affective disorder, and smoking cessation.
While neither drug alone has been approved for weight loss, when used as directed with a reduced-calorie diet and exercise, Contrave can provide a new option for chronic weight management.
It has been approved for use by adults who are obese or overweight with at least one other weight-related condition such as high blood pressure or type 2 diabetes. Contrave is the third drug approved for weight loss in the last two years, following Belviq (lorcaserin) and Qsymia, though neither has sold well. Pharmacies are expected to stock Contrave in a few months.
Does Contrave work?
After a year of treatment, Contrave was approved by the FDA based on the findings of multiple clinical trials involving 4,500 overweight and obese men and women, some of whom had weight-related conditions.
In one trial that involved people without diabetes, 42% of those who were treated with Contrave lost at least 5% of their body weight, compared to only 17% of those who were given a placebo. In another trial that included people with diabetes, 36% of those taking Contrave lost at least 5% of their body weight, compared to 18% of those taking a placebo.
While some participants in the studies experienced more significant weight loss, over 50% experienced little to no weight loss. The FDA recommends discontinuing the use of Contrave if it does not produce any positive results after 12 weeks.
How does it work?
It is unclear how the combination of a drug for addiction and one for depression may aid in weight loss. However, it is possible that these drugs affect the areas of the brain responsible for impulse control, reward processing, and hunger regulation, leading to reduced appetite and a decreased desire for food as a means of comfort.
Downsides of Contrave
Contrave, like any medication, may cause adverse effects. These include nausea, vomiting, constipation, headache, dizziness, insomnia, dry mouth, and diarrhea. It may also elevate blood pressure and heart rate and lead to seizures.
As bupropion has been linked to suicidal thoughts, Contrave carries a black-box warning about this potential side effect. Similarly, naltrexone use has been associated with seizures.
Therefore, individuals with a seizure disorder, uncontrolled high blood pressure, eating disorder, narcotic addiction, or who are taking medication to treat addiction should avoid taking Contrave due to the side effects and warnings associated with it.