The drug is used for weight management in those who have either high blood pressure, high cholesterol or type 2 diabetes and have a BMI (Body Mass Index) of 27 or greater. A BMI of 27 makes someone overweight, while a BMI of 30 classifies them as obese. It should be used for chronic weight management as an addition to a reduced calorie diet and exercise.
Belviq, which is manufactured by the Swiss based company Arena Pharmaceuticals Gmbh., is a slightly different approach to finding the holy grail of weight management. In an approach somewhat similar to the drug Chantex for quitting smoking, it works by reducing cravings. Belviq activates the serotonin 2C receptor in the brain and should help a person eat less and feel full after eating smaller amounts of food.
Janet Woodcock, M.D., director of the FDA's Center for Drug Evaluation and Research
"Obesity threatens the overall well being of patients and is a major public health concern ... The approval of this drug, used responsibly in combination with a healthy diet and lifestyle, provides a treatment option for Americans who are obese or are overweight and have at least one weight-related comorbid condition."
The safety and effectiveness of Belviq has been evaluated in three randomized trials that took place over 1-2 years and involved some 8,000 overweight and obese patients some of whom were also suffering type 2 diabetes. The patients also engaged in lifestyle changes, including exercise and a reduced calorie diet. When compared with those on a placebo, the average weight loss ranged from 3 to 3.7%.
Those patients not suffering from type 2 diabetes lost at least 5 percent of their body weight, compared with only 23 percent on the placebo. 38 percent of patients with type 2 diabetes and 16 percent treated with placebo also lost at least 5 percent of their body weight. Belviq also seemed to help those with type 2 diabetes, presumably the reduction in cravings, meant less intake of snacks, as favorable changes in glycemic control were seen. The FDA recommended that a labeling be included with the drug to recommend patients not losing weight after 12 weeks to cease taking the drug, because trials suggest that the drug will not be effective for them in obtaining a meaningful weight loss.
Belviq can cause some serious side effects, particularly when taken with other medicines that increase or activate serotonin levels, such as those used to treat depression and migraine. Belviq cannot be used during pregnancy and may also cause memory and attention issues. The drug was previously denied approval in 2010 due to concerns of tumors found in animal tests.
It is known that the number of serotonin 2B receptors may be increased in patients with congestive heart failure, therefore the FDA recommended using it with caution in patients with this condition. The Belviq clinical trials included echocardiography to assess heart valve function in the 8,000 patients and while no serious changes were seen between those on the drug, and those on the placebo, the FDA feels the caution is more than warranted after previous experiences with these kinds of weight loss drugs. Back in 1997, fenfluramine and dexfenfluramine had to be taken off the market with evidence emerging that they caused heart valve damage. At the time, it was thought that the effect was related to activation of the serotonin 2B receptor on heart tissue, but in Belviq used at the approved dose of 10 milligrams twice a day there doesn't appear to be activate the serotonin 2B receptor occurring.
The FDA said it will require the drug's manufacturer to conduct six postmarketing studies, including a long-term cardiovascular assessment, to ensure levels of heart attack and stroke are not increasing in those on the drug. The most common known side effects of Belviq in non-diabetic patients are headache, dizziness, fatigue, nausea, dry mouth, and constipation, and in diabetic patients are low blood sugar (hypoglycemia), headache, back pain, cough, and fatigue.
Written by Rupert Shepherd