Withdrawal Not a Problem with Phentermine
Trigger warning: Discussion of the diet drug phentermine.
Another one of my MedPage Today articles caught my eye. This time, the headline read, “Withdrawal Not A Problem With Phentermine.”
Phentermine, a common diet drug that has been on the U.S. market since 1959, is pharmacologically similar to amphetamine. It’s often prescribed long-term to help patients lose weight.
Given its similarity to the stimulant amphetamine, some researchers have suspected that phentermine may also lead to withdrawal once it’s stopped.
Because phentermine acts like, and is similar to, amphetamine, doctors have worried about withdrawal effects on patients. I noticed that phentermine has been available and prescribed since 1959, and some patients have been on it as long as eight years. So doctors are worried about withdrawal symptoms/effects, but they’re still prescribing it without knowing if those effects exist or what their severity is. Why do I get the feeling this kind of thing really isn’t about health, but is about aesthetics?
But only the hyperphagia score was significantly different across groups, rising from 0.77 on-drug to 1.16 the first day off the drug and 1.03 on the second day (P=0.027).
Hyperphagia is defined as abnormally increased appetite for consumption of food.
What these researchers found is that the day after phentermine is abruptly stopped, appetite increases (no shit, Sherlock). The researchers also say that this effect goes away after a couple of days, but they don’t say how they know this as the questionnaire they gave to participants only covered the time while they were taking the drug and the two days after it was stopped. They don’t say if there was any further follow-up to see if patients’ appetites were still increased after that.
Thus, after hyperphagia score was removed from the total, the remaining scores based on 9 items were not significantly different across days, the researchers reported (P=0.084).
Hendricks and colleagues noted that these scores are far lower than scores achieved on the amphetamine withdrawal questionnaire.
He also added that phentermine is not available in Europe: “Worldwide usage of phentermine has been curtailed because of persistent fears that the drug might induce addiction and that it might induce cardiovascular harm. However, this study suggests fears of causing addiction with long-term phentermine prescribing are exaggerated and present a needless barrier to better care for overweight and obese patients worldwide,” he said in a statement.
Right, because even the risk of cardiovascular harm is better than being fat (/sarcasm).
So, the researchers found that phentermine is not addictive, but it’s not available in Europe because of the fear of addiction, and the fear that “it might induce cardiovascular harm” (phen-fen, anyone?). We don’t have to worry about becoming addicted to phentermine, but the researchers don’t address the fears about it causing cardiovascular harm. I guess that’s a risk they’re willing for fat people to take in order to try and become thin. I don’t even know what to say about people who think like this (well, I do, but I don’t think anyone wants to read a long string of swear words).
Even if phentermine isn’t addictive, the cardiovascular issues just isn’t a risk I would be willing to take now that I know it exists (I didn’t know about the risk back in 1996 when I took phen-fen for six months, right before it was taken off the market).
The drug’s structural similarity to amphetamine “has led many to presume that phentermine should have the same adverse effects as crystal methamphetamine,” Hendricks said. “No evidence supporting such presumptions is to be found.”
“On the contrary,” he added, “the evidence strongly suggests phentermine is far safer than is commonly assumed. It is indeed unfortunate that these misconceptions hinder the availability of an effective, affordable medicine for treating obesity.”
Safer because it’s not addictive? Safer because you don’t know the risks of cardiovascular harm? *headdesk*
It’s worth noting that the results of the yet-to-be-published study were reported at the European Congress on Obesity (ECO) in Liverpool, England by lead author Dr. Ed Hendricks of the Center for Weight Management in California, which is a a non-public fee-for-support health-related practice specializing in weight problems drugs or bariatric medication. ECO is an annual meeting of the European Association for the Study of Obesity. ECO is sponsored by corporates sponsors involved in biomedical research, the treatment of obesity-related diseases, and, of course, weight loss companies like Eurodiet, Pronokal, Cambridge Weight Plan, Slimming World, LighterLife, Weight Watchers, and Nestlé.
Even more interesting is that the study was supported by the American Society of Bariatric Physicians, and lead author Hendricks received honoraria from Akramax, Eurodrug Laboratories, Citius, and Vivus, all of which manufacture phentermine products. Coauthor Dr. Frank Greenway reported relationships with Baronova, Basic Research, Diabetic Living, Eisai, GNC, Jenny Craig, Lithera, Merck, Naturalpha, Nume Health, Orexigen, Plensat, Takeda, Thetis, Unigene, and Zafgen.
I’m sure none of these conflicts of interest had any influence on the final outcome.