The Food and Drug Administration recently approved anti-obesity pill Belviq, the first new prescription drug for long-term weight loss to enter the U.S. market in more than a decade.

Despite achieving only modest weight loss in clinical studies, Belviq appeared safe enough to win the FDA’s endorsement.

The agency cleared the pill for adults who are obese or are overweight with at least one medical complication, such as diabetes or high cholesterol.

Arena and its partner Eisai Inc. of Woodcliff Lake, N.J., expect to launch the drug in early 2013.

With U.S. obesity rates nearing 35 percent of the adult population, many doctors have called on the FDA to approve new weight-loss treatments.

But a long line of prescription weight-loss offerings has been associated with safety problems, most notably the fen-phen combination, which was linked to heart-valve damage in 1997.

As obesity rates in the U.S. rise and as Belviq makes national headlines, we asked three local experts to discuss the pros and cons of this new prescription drug.

How Belviq works

Belviq works by activating the serotonin receptors in the brain, according to Dr. C. Joe Northup, medical director of Mercy Health - Healthy Weight Solutions in Fairfield.

“Activation of this receptor may help a person eat less and feel full after eating smaller amounts of food by controlling appetite,” he said.

Belviq can be taken by patients with a body mass index of 30 or higher or a BMI of 27 with a weight-related disease, he said.

Patients should be under a doctor’s care and must be closely monitored when taking Belviq, Northup said.

In the study submitted to the FDA, nearly 50 percent of patients without type 2 diabetes lost at least 5 percent of their body weight — an average of 12 pounds, Northup said — compared with about 23 percent of patients treated with a placebo.

According to Northup, the most common side effects of Belviq in nondiabetic patients are headache, dizziness, fatigue, nausea, dry mouth and constipation. In diabetic patients, side effects include low blood sugar, headache, back pain, cough and fatigue. Other potential side effects of Belviq include symptoms such as confusion, restlessness, blood pressure changes, nausea, vomiting and loss of muscle coordination, he said. Another concern is the development of cardiac complications similar to those seen in fen-phen patients, Northup said.

“In general, any weight loss medication should be taken with caution,” he said. “ ... It is unlikely that we will ever see a medication to replace portion control, healthy choices and exercise. With Belviq being so new to market, I would have some reservations as a patient taking this medication. Longer term studies are needed to determine if the average 12-pound weight loss will outweigh the risk of potential side effects.”

Rewards, risks of Belviq

Belviq may be an effective weight-loss tool for some people, according to Carla Metzler, a registered, licensed dietitian at Fort Hamilton Hospital.

“When used along with behavior modification, like dietary changes and increasing activity, these medications can expedite weight loss,” she said. “As people see faster results, they tend to be more committed to their weight-loss plans. This particular medication does not speed up a person’s system as medications like phentermine can, but works as an appetite suppressant by activating the serotonin 2C receptors in the brain. This appetite control can help individuals who are trying to control their caloric intake to stick with the dietary changes.”

As with any medication, there are a number of potential side effects, Metzler said. Medical supervision is required for safety, she said.

“My biggest concern is the fact that most doctors who prescribe these medications are not utilizing registered dietitians for the diet education and piece, which is key to long-term success with weight management,” Metzler said.

“These meds can help the patient lose the initial weight; however, without a long-term nutrition plan, the research indicates that the majority of the weight lost is re-gained, or actually a higher weight is reached.”

This nutrition plan includes a post-weight loss, weight management diet and activity plan to help keep the lost weight from being regained, according to Metzler.

“Losing weight is sometimes the ‘easy’ part,” she said. “Keeping the weight off is the challenge and is the part [in which] I like to help my clients find real success.”

Weight-loss alternatives

There are several alternatives to drugs like Belviq for those who want to lose weight, according to Dr. Donovan Teel II, a bariatric surgeon and the assistant medical director of the Weight Loss Surgery Center at Miami Valley Hospital in Dayton.

Alternatives include low-calorie diets, increasing exercise and surgical options, he said. Currently, the most popular and effective surgical procedures for weight loss include the laparoscopic sleeve gastrectomy and laparoscopic gastric bypass, according to Teel.

Compared with a placebo, treatment with Belviq for up to one year is linked with an average weight loss ranging from 3 percent to 3.7 percent, Teel said.

“Surgical weight loss on average will yield 50 to 80 percent excess weight loss in one year, with people often taking significantly less medications,” Teel said. “ ... Metabolic surgery (weight-loss surgery) does have a slightly higher short-term risk profile than medications such as Belviq.”

Overall, all weight-loss methods, whether medication or surgery, are tools to help a person maintain a healthy, low- calorie diet, according to Teel.

“This low-calorie diet is what leads to weight loss,” he said. “Every tool can be broken if used improperly, so it is very important to understand the strengths and weaknesses of the different tools in order to achieve success at becoming healthier and living longer.”

Contact this reporter at (937) 225-2122 or Jacqueline. Boyle@coxinc.com. The Associated Press contributed to this report.