Blog | Tuesday, February 7, 2012

Freebies leave one internist wanting something more--the truth

Once upon a time we used to let drug reps feed us, bring us tchotchkes, and generally use our time. The staff liked the free food, and our patients liked the free drug samples. But we didn't like how it made us feel. The pharmaceutical companies have stopped giving out pens and such, and we have stopped allowing them to bring us lunches. There are a few samples which are still useful, especially respiratory drugs that aren't available as generics. To this, we give in, and we do allow reps to stop by the office with samples, occasionally taking a bit of our time.

Studies show that these interactions affect prescribing patterns. I'm not happy about it, but it's hard to get some drugs for my patients. The reps know me well enough to know that I don't like to be detailed and that I'm pretty easily annoyed. They're tenacious beasts though. A new one stopped by today.

She was trying to get me to prescribe a drug called Glumetza (Santarus, Inc.). It's a diabetes drug. In fact, it's a really good diabetes drug. Not only is it a good diabetes drug, but it's laughably cheap, although not under that name.

Glumetza is metformin, a drug also branded as Glucophage, in an extended release form. Metformin costs about $4 per month. The extended release version costs about $10 to $15 per month. Glumetza costs about $250 per month. This must be some sort of uber-metformin, right? At that price it better lower your sugar and wipe your ass for you.

And that's basically what it claims to do. One of the problems with metformin is that it can cause some stomach upset, especially diarrhea. In nearly all patients, this wears off in a few days, and when it doesn't, changing to the extended release form ($10 to $15 per month, remember?) usually does the trick. What does Glumetza claim? "Unlike immediate-release metformin, GLUMETZA uses a special advanced polymer technology that delivers the medicine slowly and steadily over several hours.5 This delay in the release of the medicine may result in fewer stomach-related side effects, such as nausea, in the 1st week of taking the medication.4"

I don't doubt that the company has a proprietary drug delivery system. But what about the other claims?

The footnotes point to:
1. The Glumetza package insert
2. An inaccurate citation, but allows me to track down a journal article about extended-release metformin, not Glumetza specifically
3. A patent summary
4. A study that compared Glumetza, extended-release metformin, and immediate release metformin. What did it find? We'll get to that.
5. A footnote leading nowhere.

Footnote 4′s study found that: "Even with a 1,000-mg q.d. starting dose, the overall incidence of gastrointestinal adverse events during the 1st week of dosing was low and comparable among treatment groups (Table 3). There was a higher incidence of nausea in the immediate-release metformin group than in the extended-release metformin groups (P=0.05). In addition, there were more adverse events of nausea and diarrhea causing treatment discontinuation in the immediate-release metformin group than in the extended-release metformin groups. The overall incidence of adverse events considered possibly or probably related to the study drug was similar for all treatment groups; the only such events reported for greater than 5% of patients in any treatment group were gastrointestinal events."

In other words, all forms of metformin were well-tolerated. Even so, there was a measurable difference between the immediate release form and the extended release forms. There was no convincing evidence that Glumetza was better than the cheaper, generic extended release metformin. The discussion tries to be convincing, but the data don't back any other conclusion: Glumetza is different than generic metformin--it costs more money.

The lesson here isn't that medicine is bad. Metformin is a terrific drug, and cheap. But the marketing of predictable and high-priced knock-off drugs does nothing to contribute to our health. And plenty of physicians and patients fall for the not-so-cheap marketing.

Peter A. Lipson, ACP Member, is a practicing internist and teaching physician in Southeast Michigan. After graduating from Rush Medical College in Chicago, he completed his internal medicine residency at Northwestern Memorial Hospital. This post first appeared at his blog, White Coat Underground. The blog, which has been around in various forms since 2007, offers "musings on the intersection of science, medicine, and culture." His writing focuses on the difference between science-based medicine and "everything else," but also speaks to the day-to-day practice of medicine, fatherhood, and whatever else migrates from his head to his keyboard.