When a drug is protected by patent, the manufacturer may spend a lot of money advertising and promoting the drug. Many authorities are opposed to this expenditure. For example, Marcia Angell, the former editor of the New England Journal of Medicine, wrote an entire book, The Truth about the Drug Companies: How They Deceive Us and What to Do about It, complaining about the behavior of major pharmaceutical companies, including their advertising and promotion expenditures.

However, when a drug is not covered by patent, there may also be harm to public welfare. Without a patent, the manufacturer will have little incentive to provide information to physicians or patients about the drug’s benefits. As an example, consider the drug metformin, also called Glucophage, a major anti-diabetes medication.

Prevention / Metformin was invented in the 1920s, but not widely used until much later; it was only introduced in the United States in 1995. It is now the most widely prescribed anti-diabetic drug in the world. It is no longer covered by patent and generic versions are available at major drugstores for as little as $4 per month. Sometimes, it can even be had for free. Side effects for healthy individuals are minimal and there is some evidence that the drug reduces other health risks, including cancer.

The drug is commonly prescribed for treatment of Type 2 diabetes and is very effective. However, there is substantial evidence that it is also useful for preventing diabetes in people with somewhat elevated blood sugar (sometimes called “prediabetes”). The best evidence is that metformin alone can reduce diabetes risks by about one-third after three years of use. This effect persists for at least 10 years of use, although the magnitude is reduced over time. Major lifestyle changes, including significant weight loss, are more effective, but much more difficult and more expensive to achieve.

Why is the drug not used more broadly for prevention? The use of statins and aspirin, which help to prevent heart disease, indicates that significant numbers of people can be convinced to take a daily medication to prevent a future disease even in the absence of symptoms. But there are some important differences between the statin regimen for preventing heart disease and the metformin regimen for preventing diabetes. The most important difference is that during the period when statins were becoming popular, they were protected by patents. This means that the drugs were much more expensive (although generally covered by insurance). It also means, however, that the pharmaceutical companies were willing to spend significant resources providing information about the drugs to physicians and patients through expenditures on promotion. Metformin is no longer covered by patent and is made by several generic producers, so there is relatively little money to be made from promoting it, so no one has much incentive to do so.

Because of the lack of promotion, many physicians may be unaware of the preventative uses of the drug. (Anecdotally, I have found this to be true. I have taken the drug for several years and whenever I see a new physician I must convince him or her that I am not a diabetic.) Moreover, many physicians are biased against drugs and prefer to recommend their patients simply follow a regimen of “diet and exercise,” a proposal that is easy for doctors to prescribe but hard for patients to follow. Of course, diet and exercise is a sensible recommendation, especially since the same evidence that indicates metformin is useful also indicates that diet and exercise is more effective. However, if a physician observes that a patient is not getting any thinner and blood sugar remains elevated, metformin should be (but often is not) the alternative.

The U.S. Food and Drug Administration has approved metformin for diabetes treatment, but not prevention. Physicians are allowed to prescribe an approved medicine for any condition, so the lack of FDA approval does not mean the drug cannot be used for prevention. However, firms are not allowed to advertise or promote a medicine for an unapproved use. That lack of promotion means that physicians are significantly less likely to understand the benefits and prescribe the drug. Moreover, because the drug is not protected by patent, no one has the incentive to spend the resources needed to convince the FDA to approve the drug for prevention, even when—as in metformin’s case—the evidence is solid.

Suggestions / If you are a person with somewhat elevated blood sugar, ask your physician to prescribe metformin. If the doctor refuses, you may want to seek another physician. Use of this drug can increase length and quality of life, and is worth the bother of seeing another doctor.

If you are a doctor, consider prescribing metformin for your patients with elevated blood sugar, particularly if previous suggestions to lose weight and increase exercise have not worked. After the third or fourth unsuccessful admonition to lose weight, another approach is needed.

If they can find a way, FDA officials should seriously consider approving this drug as a diabetes preventative. Moreover, the drug is sufficiently beneficial and safe that it should be considered for over-the-counter sale. A public health campaign promoting the drug as a preventative could improve and lengthen many lives. It is sad that there is a significant remedy for a condition that is often described as an “epidemic” and yet our regulatory institutions are such that no one is making an effort to use it.