Belviq (lorcaserin hydrochloride) helps a person feel fuller sooner while eating so that they will eat less food. It does this by activating a serotonin receptor in the brain.
"Have a doctor help you define a weight loss plan."
Belviq is not for just anyone who wants to lose weight. It should be combined with a lower calorie diet and exercise for a specific population.
The drug is intended for adults who have a body mass index (BMI) of 30 or higher, or for adults with a BMI of 27 or greater who also have a weight-related health condition, such as high blood pressure, type 2 diabetes or high cholesterol.
Body mass index is a ratio of a person's height to weight, and 30 or higher is classified as obese.
Belviq has undergone testing in three clinical trials in which people were randomly assigned to take Belviq or to take a placebo - a fake pill without active ingredients - without knowing which pill they were being given to take.
Almost 8,000 adults took part in the trials, which lasted from 52 to 104 weeks. Some of the participants had type 2 diabetes, and some did not. All the adults in the trial also received exercise counseling and a reduced-calorie diet.
The participants who took Belviq lost an average of 3 to 3.7 percent of their weight compared to the group taking the placebo. About twice as many of the patients lost 5 percent of their body rate while taking Belviq compared to the placebo group, whether the patient had type 2 diabetes or not.
Among those without type 2 diabetes, 47 percent lost at least 5 percent of their body weight. The figure was 38 percent for people taking Belviq who had type 2 diabetes. Those type 2 diabetes also had better glycemic control, or the body's ability to control blood sugar, while taking Belviq.
The FDA notes that a patient who has not lost about 5 percent of their body weight after taking Belviq for 3 months should stop taking it because they are unlikely to lose a worthwhile amount of weight.
Belviq should not be used by women who are pregnant, the FDA wrote, and it can have serious side effects if taken with medications that increase serotonin or activate serotonin receptors.
Various mental health medications prescribed for depression, anxiety or migraine interact with serotonin levels, so patients should be aware that Belviq may not be recommended when a patient is taking any of these other medications.
Belviq works similarly to two past weight loss drugs that were withdrawn from the market when it was discovered that they could cause heart valve damage: fenfluramine, which was one component in the drug Fen-Phen, and Redux (dexfenfluramine).
These drugs activated a brain receptor called serotonin 2B, which researchers believe also contributed to the heart tissue problems.
Belviq, however, works on the serotonin 2C receptor. According to FDA materials, a dosage of 10mg twice a day of Belviq does not appear to have any effect on the serotonin 2B receptor.
When the functioning of the heart valve was tested on the approximately 8,000 patients who were part of the Belviq clinical trials, researchers saw no major differences between the participants taking Belviq and those taking a placebo pill that did not contain the active ingredients of Belviq.
Still, the FDA recommends caution for patients who have congestive heart failure or valvular heart disease regarding this medication since there are not studies to confirm whether it is safe for these patients.
Belviq can cause some problems with attention or memory, the FDA reports. The side effects that were reported by most people taking Belviq include headache, dizziness, fatigue, nausea, dry mouth and constipation.
Diabetic patients who took Belviq reported having low blood sugar, headache, back pain, a cough and fatigue.
The approval was Belviq was announced by the FDA on June 27. The drug is manufactured by Arena Pharmaceuticals GmbH of Zofingen, Switzerland, and distributed by Eisai Inc. of Woodcliff Lake, N.J. Arena is required by the FDA to conduct six more studies on Belviq, including a long-term trial to see if it is associated with any cardiovascular problems.