Adapted from an article by David Katz, MD
There are currently three new weight loss drugs in the front of the queue for FDA consideration — Qnexa, Contrave and lorcaserin — and all of them made news this week.
Perhaps the lead news item is that an advisory panel to the FDA recommended against approval for Qnexa, a drug that combines phentermine (an amphetamine) and topiramate (an anti-convulsant). The drug produces weight loss, but at a cost in brain function — impaired concentration and memory loss — the advisory committee deemed too high. (I am tempted to consider that people taking the drug simply don’t remember to eat, but that may take things too far.) The FDA is likely to follow the advice of its expert panel on this one.
Contrave is in the news at the moment only by association. This drug, a combination of the antidepressant bupropion and naltrexone, a drug used for treating addiction, comes up for its own FDA review later in the year. It appears to be slightly less effective than Qnexa, and perhaps slightly less encumbered by side effects, although nausea appears to be common enough to be rate-limiting.
The third drug, lorcaserin, which influences brain serotonin levels, was featured in a clinical trial just published in the New England Journal of Medicine. Most news reports seem to be putting a positive spin on the trial, which found the drug produced a 5 percent or greater weight loss when combined with a lifestyle intervention more often than the lifestyle intervention alone. But half of the study participants dropped out, and the rather modest weight loss achieved in those who remained lasted reliably only as long as they kept taking the drug. Half who stopped the drug gained back the weight, despite the lifestyle intervention. The drug company that sponsored the trial waxed optimistic, but honestly, I am much underwhelmed.
Anyone surprised by this most recent and potentially discouraging installment is either a perennial optimist, or hasn’t been paying much attention. Because the history of weight loss drugs is a litany of disappointments, large and small. From the infamous demise of Fen-Phen, a combination antidepressant and stimulant that caused heart valve damage (due, most now concur, to the ‘Fen,’ or fenfluramine, not the ‘Phen,’or phentermine which has reappeared in Qnexa), to the 2007 decision by the FDA to deny approval for rimonabant, the most promising weight loss drug to come down the pike in some time. FDA almost certainly got it right, however. The European Union approved rimonabant, then withdrew it from the market after noting a marked rise in the rate of depression and suicide among those taking it.
Dr. Jonny comments: This excellent summary by Dr. David Katz hits the nail on the head. The history of prescription drugs for weight loss is littered with false promises, bad side effects and FDA recalls. And the real kicker is that none of them work all that well to begin with, despite enormous hype and advertising.
Before going the drug route, why not really see what eating and living differently can achieve. Lifestyle changes — and I’m talking deep, profound changes, not quick-fix diets — may not be all that sexy, and certainly don’t produce instant gratification.
But they do produce real change.
And the only “side effects” are good ones.
You can read the full text of Dr. Katz’s article here