The FDA recently approved the first weight-loss drug, Belviq (lorcaserin hydrochloride), in 13 years. Arena Pharmaceuticals of San Diego developed the pill to help people lose 3-4% of their body weight when coupled with exercise and a healthy diet. The FDA approved the pill for obese people (BMI over 30) and some overweight people (BMI over 27) who suffer from high blood pressure, high cholesterol, and type 2 diabetes.
Potential weight-loss drugs face increased scrutiny tod
ay by the FDA for efficacy and safety as many recent ones (fenfluramine, for example) have been recalled due to heart-valve complications. In March, the FDA’s advisory committee introduced mandatory tests for cardiovascular risks for all obesity drugs, which makes the current clinical trials even longer.
In 2010, Arena applied for approval of the drug. The FDA denied approval because it was deemed responsible for causing tumors in rats and because it could not definitively rule out an increase in heart-valve defects. The pharmaceutical company conducted echocardiograms for 8,000 patients to determine heart-valve function. This trial could not verify an increase in heart-valve defects in the users of the drug, convincing the FDA to approve it. The company committed to perform six post-marketing studies with a long-term cardiovascular trial that will search for heart attack and stroke risks.
The drug works to suppress food cravings by mimicking the effects of serotonin in the brain. Along with many other vital functions, the neurotransmitter serotonin plays a role in controlling appetite. Within the brain, neurons pass messages back and forth using chemical messengers (neurotransmitters). The messages may involve information concerning emotions, body temperature, behavior and appetite. The specific kind of information delivered varies with which neurons become activated and where the brain becomes stimulated. The neurotransmitter leaves the neuron and enters the synapse (the space between the two “communicating” neurons). The neurotransmitter links with the receptor on the other neuron, which sends the message. This can then be repeated through a process called reuptake. Serotonin qualifies as a neurotransmitter. The drug Belviq mimics serotonin by activating the 2C receptor, which increases the amount of serotonin to carry messages and increases the probability that the message is received. Thus, the drug causes people to eat less and feel full.
Non-diabetic patients reported headache, dizziness, fatigue, nausea, dry mouth and constipation as side effects. Other side effects include serotonin syndrome especially in combination with depression or headache medication that increase serotonin levels or that activate serotonin receptors. The drug may also affect attention or memory. In diabetics, side effects include low blood sugar, pain, cough and fatigue.
On average, a 198-pound patient taking Belviq will lose six to seven pounds in a year. 20% of patients lose at least 10% of their body weight. Comparatively, 47% of patients without type 2 diabetes taking the drug and 23% of those taking a placebo each lost at least 5% of their total body weight. 38% of patients with type 2 diabetes taking the drug and 16% of those taking a placebo each lost at least 5% of their total body weight. Type 2 diabetics who toke Belviq proved to be twice as likely to regulate their blood sugars compared to those who toke the placebo.
While it may help those suffering from diabetes, it may cause heart complications. The company advises patients with congestive heart failure or pregnant patients to not take the drug. CNN’s Dr. Melina Jampolis, a physician nutrition specialist and diet and fitness expert, calls the results modest and says, “But most experts agree that even a 5% weight loss has significant implications in terms of reducing the risk of obesity associated diseases including heart disease and diabetes.”
The drug may be risky, but risks also come with the rising obesity rate such as diabetes and heart disease. With more than 1/3 of the adult population being obese, the drug may prove worthwhile.