Why I'm Wary of the New Weight-Loss Drug Belviq Lindsay Beyerstein fears it's being viewed as the next fen-phen By Kate Seamons, Newser Staff Posted Jul 3, 2012 1:58 PM CDT Updated Jul 8, 2012 10:51 AM CDT 9 comments Comments This photo provided by Food and Drug Administration shows Arena Pharmaceutical's anti-obesity pill Belviq. (AP Photo/Food and Drug Administration) (Newser) – The FDA has green-lighted the first new prescription weight-loss drug in 13 years—and Lindsay Beyerstein isn't exactly tossing confetti into the air at the news. Writing for Slate, she asserts that Belviq is no wonder drug: In trials, patients lost about 3% of their initial body weight, which works out to just six pounds off a 200-pound frame. And to keep the weight off, they have to keep taking the drug forever. That makes it unworthy of excitement in her book, but here's what makes it worthy of worry: Some physicians hope Belviq will be a safe sub for fenfluramine—that's right, the "fen" in fen-phen. Fen-phen, you'll remember, was "the Holy Grail of long-term obesity treatment" until the FDA realized that as many as a third of fenfluramine users developed heart valve damage. The way Belviq stimulates serotonin activity (specifically) is supposed to be safer than the way fenfluramine did (indiscriminately), but a bel-phen combo has never been tested. And some doctors are eager to give the combo a go, writes Beyerstein, who notes that "pharmaceutical companies often seek approval for a narrow indication, knowing that doctors can and will prescribe the drug much more widely. Obesity medicine is full of frustrated doctors and desperate patients, demographics that have historically been easy pickings for snake oil salesmen. Don't buy the hype." Click for Beyerstein's full column.