(Rogelio V. Solis/AP)

The Food and Drug Administration has approved the latest prescription diet pill, Contrave, which is a combination of two previously FDA-approved drugs that treat addiction and depression.

The drug is the latest tool in physicians' arsenals for the treatment of obesity, a growing epidemic in the United States. According to the Centers for Disease Control and Prevention, more than 35 percent of adults are obese.

With diet and exercise, the drug is approved for adults with a body mass index of 30 or greater or with a BMI of 27 or greater, as long as they also suffer from at least one other weight-related condition like high blood pressure, Type 2 diabetes or high cholesterol, the FDA said.

Contrave helped patients lose more weight compared to a placebo in clinical trials involving 4,500 obese and overweight people.

With diet and exercise, the drug is approved for adults with a body mass index of 27 or greater, as long as they also suffer from at least one other weight-related condition like high blood pressure, Type 2 diabetes or high cholesterol, the FDA said. Persons with a BMI of 30 or above can be prescribed the drug without consideration of compounding conditions.

In people with diabetes evaluated in a second trial, those patients lost an average of 2 percent more weight compared to the placebo. And 36 percent of people taking Contrave lost at least 5 percent of their body weight compared to 18 percent of people taking a placebo.

But like a lot of other prescription diet pills, it is accompanied by warnings of serious risks and side effects.

The extended release form of two component drugs — naltrexone, which treats alcohol and opiate addiction, and bupropion, which treats depression and seasonal effective disorders, and is used to help smokers quit — are combined in Contrave.

The FDA warns that because it contains an anti-depressant, bupropion, there are risks of increased suicidal thoughts and behaviors that are usually associated with those types of drugs. And there are even reported neuro-psychiatric events associated with bupropion in patients using it as a smoking cessation aid.

The diet pill Contrave can also cause seizures, raise blood pressure and heart rates. So people who have a history of seizures shouldn't take it, and neither should people who have uncontrolled high blood pressure.

Concerns about heart-related side effects have been a reoccurring problem for diet drugs, particularly since the recall of Fen-Phen in 1997 due to concerns about heart damage caused by the drug. But despite those concerns, an FDA advisory panel endorsed Contrave in 2010, saying that weight loss benefits outweigh the health risks.

And in 2012, two other drugs, Qsymia and Belviq, were approved by the FDA for weight loss.

Patients who take the newest drug, Contrave, are supposed to be closely monitored and reevaluated after 12 weeks. If the person has not lost at least least 5 percent of their body weight, its use should be discontinued, the FDA said.