Patients on the highest dose of Qnexa lost an average of 8.9 percent of their weight after adjusting for the effects of a placebo. More than 60 percent of patients on middle and high doses lost at least 5 percent of their weight, compared with 20 percent for those getting a placebo.
— NY Times
Recall that the National Institutes of Health states that a “8-15% weight loss is often observed” from dieting. So losing an average of 8.9% doesn’t seem all that to me. It is enough for the FDA to consider it an effective weight loss treatment, though, because the FDA requirements are:
[A] drug will be considered effective if at least one of the following criteria is satisfied after one year of treatment:
- The difference in mean weight loss between the active-product and placebo-treated groups is at least 5 percent and the difference is statistically significant
- The proportion of subjects who lose greater than or equal to 5 percent of baseline body weight in the active-product group is at least 35 percent, is approximately double the proportion in the placebo-treated group, and the difference between groups is statistically significant
5% of baseline weight on average over a placebo. For a 200lb person, that’s 10lbs. That’s what’s required to be an effective weight loss drug.
I think that says something pretty damning about the supposed ease of weight loss.
Meanwhile, the risks of Qnexa include suicidal thoughts, problems with thinking, birth defects, speeding heart rates and acid buildup. I wouldn’t want to risk taking it.
Does this sound worth it to you? Or do you figure it’s at least better than Alli?
More info: FDA review (PDF)
7/15 Update: FDA panel rejects Vivus weight-loss drug Qnexa