FDA Approves Rx for Weight Loss

Contrave approved for use in conjunction with diet and exercise

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) The US Food and Drug Administration (FDA) approved a new weight-loss pill Sept. 10 for use in obese and overweight adults.

A combination of two other FDA-approved medicines, Contrave is approved for use in adults along with reduced-calorie diets and exercise.

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“Obesity continues to be a major public health concern,” said Jean-Marc Guettier, MD, director of the Division of Metabolism and Endocrinology Products at the FDA’s Center for Drug Evaluation and Research, in a press release. “When used as directed in combination with a healthy lifestyle that includes a reduced-calorie diet and exercise, Contrave provides another treatment option for chronic weight management for people who are obese or are overweight and have at least one weight-related health condition.”

Contrave is made up of naltrexone hydrochloride and bupropion hydrochloride. Naltrexone is used to treat dependence on alcohol and opioids. Bupropion treats depression and nicotine addiction.

"Both medications have been used individually by some clinicians for several years as treatment of obesity," said E. Lee Carter, RPh, Clinical Pharmacy Specialist at the Department of Veterans Affairs in Prestonsbrug, Kentucky. "Now the FDA has approved the combination in a single medication for this indication."

According to Carter, "Contrave works differently than other available weight loss medications such as orlistat (Xenical) or phenterimine (Fastin, Adipex, others), and the mechanism of action is still not well understood."

The extended-release tablet has undergone many clinical trials. One such trial found that 42 percent of obese patients without diabetes lost at least 5 percent of their body weight after one year of Contrave use — compared to 17 percent of patients who took an inactive pill. On average, patients who took Contrave lost 4.1 percent more weight than the group who didn't. Both groups began exercise and diet programs during the study.

Another study found similar results but also included patients with type 2 diabetes. Among the patients who took Contrave, 36 percent lost at least 5 percent of their body weight — versus 18 percent of patients treated with an inactive pill.

In a press release, the FDA noted that patients who take Contrave should stop taking it after 12 weeks if they have not yet lost at least 5 percent of their body weight. This is because, at this point, Contrave won't likely cause meaningful weight loss.

Contrave carries a boxed warning that notes the potential for suicidal thoughts and other common side effects of antidepressants. Other possible side effects include raised blood pressure, increased heart rate, nausea, headache and dry mouth.

"Patients interested in weight loss should discuss Contrave and other treatment options with their health care provider," Carter said. "Like other weight loss medications, it should be used as part of a comprehensive weight loss program, which can include behavioral modification, exercise, and in some cases, bariatric surgery."

The FDA will require Contrave to undergo more testing to further confirm its safety.

Takeda Pharmaceuticals will distribute Contrave.

Review Date: 
September 11, 2014
Last Updated:
September 11, 2014