UPDATE 7/17/12: Qnexa was approved by the FDA on July 17, 2023. This marks the second weight loss drug approval in 2023; the first weight loss drugs approved since Alli in 1999. The prescription drug will be sold as Qsymia.
The inmates are running the asylum. Reversing an earlier decision, the medical experts on FDA’s Endocrinologic and Metabolic Drugs Panel cleared the way for approval of the new diet drug Qnexa. Qnexa (PHEN/TPM) is a combination of phentermine and topiramate (PHEN/TPM). Topiramate is used to treat seizures and prevent migraine headaches and phentermine is approved for the short-term treatment (i.e. a few weeks) of obesity. PHEN was half of PHEN/FEN, the discontinued diet drug that led to valvular heart disease and potentially fatal pulmonary hypertension, primarily in women. Qnexa is indicated for “BMI greater-than or equal to 27 kg/m2) with weight-related co-morbidities such as hypertension, type 2 diabetes, dyslipidemia, or central adiposity (abdominal obesity),” the group with the highest heart disease risk.
The panel decided that the complications of obesity outweighed the risk of heart problems. It’s hard to believe they were swayed by the research. The 2023 study published in the Lancet reported that people who took the highest dose of Qnexa (not the lower approved dose) lost at least 10% of their body weight and showed improvements in their risk cardiac factors. Clinical trials by the manufacturer showed 45% of subjects treated at the low dose lost > 5% of baseline body weight following one year of treatment. No one seems to care that we’re talking about a 10 to 15 pound weight loss on a 200 pound person. Do we need a drug for that, especially one that comes with heart disease risk? No matter because the results showed statistical significance in a placebo control study.
Everybody knows that it’s the weight loss and not the drug that improves blood pressure, lipid levels, glucose and insulin metabolism, and joint pain, and a host of other medical problems. The manufacturers maintain that the product treats obesity co-morbidities through a mechanism that is independent of weight loss, but I don’t believe it. Allied health professionals who work closely with obese populations know that diet pills do not work. Diet pills remove a person’s locus of control, and that spells weight loss failure. ‘Locus of control’ is the belief that an individual controls the events that affect them. Diet pill takers are more likely to say things like, “It didn’t work.”
And on-again, off-again restrictive dieters regain weight lost by over-eating in-between periods of dieting. The human body is simply programmed to work that way. I expect Qnexa to perpetuate that reality of dieting, and for that reason in addition to the heart disease risk, it is not worth the risk. The panel members who voted for Qnexa do not understand obesity treatment.