The approach to fighting obesity using appetite suppressants came to a screeching halt in 1997, when Wyeth, the maker of the wildly successful diet drug phen-fen, was forced to withdraw the drug after the FDA received numerous reports of heart valve problems and also some cases of pulmonary hypertension, a rare but often fatal lung condition.
The ensuing lawsuits many of which were later found to be fraudulent cost Wyeth well over $10 billion and stopped the development of diet drugs dead in its tracks. Given the pervasiveness and increasing level of obesity in the US, this was particularly troubling, since phen-fen was really the only drug that was effective for weight loss.
Even though the heart valve damage was traced back to one particular metabolite of fenfluramine (the fen component of the two drug combination), the FDA tarred all potential diet drugs with a the same broad brush, even though no other candidates contained fenfluramine. This produced a moratorium, in effect, on diet drug research and development from 1997 until last year, when two new appetite suppressants, Qsymia and Belviq, were approved.
Despite the lack of phenfluramine in either of the new drugs, they were both subjected to extreme scrutiny aimed at detecting any lurking heart issues, and many critics believed that neither should have been approved because of potential heart-related side effects.
Now, those patients who have been taking Qsymia and others who have been considering it but were fearful can breathe a sign of relief. Scientists at Vivus, the maker of the drug, presented data at the American Association of Clinical Endocrinologists showing that after two years, the drug seems to be safe and effective. Furthermore, patients who lost the most weight had improvements in cardiovascular risk markers.
Charles Bowden, MD, of Vivus noted,Whether it s blood pressure or lipids, a greater degree of weight loss confers greater advantages.
ACSH s Dr. Josh Bloom is not surprised by these results. He said, Logically, there was no reason for Qsymia to cause the heart and lung problems that phen-fen did. The fact that both drugs are appetite suppressants is irrelevant. The phen-fen problems were caused by one drug that is not present in Qsymia.
You can read Dr. Bloom s 2012 op-ed entitled Qsymia is Not Fen-Phen here.