Prescription drug labels tell you how effective a drug is compared to a Placebo — a sugar pill. Labels rarely, if ever, tell you how a drug compares to other drugs. Researchers from the Stanford University School of Medicine think that they should and have published an essay in the New England Journal of Medicine explaining why.

This type of labeling should cut down on the marketing and prescribing of new drugs that have no known advantages over current ones, but cost ten times as much.

For most new drugs or medical devices to get approval, the FDA requires only that they be shown to be safe and more effective than a placebo. Proof of a drug’s superiority to existing drugs is only required in certain cases, such as treatments for AIDS or cancer.

How can doctors possibly prescribe the best drugs for their patients when the drugs haven't been tested against each other?

There's a natural tendency for patients to want and doctors to prescribe the newest drug, assuming that newer is better. But there's rarely any proof that this is true. What is true is that newer treatments are nearly always more expensive than older treatments.

Lead author Randall Stafford, M.D., Ph.D. and associate professor of medicine at the Stanford Prevention Research Center, explains that current regulations favor creation of new drugs that differ little from the old ones, though they are often marketed as "next generation." This benefits the drug companies much more than it benefits patients. Stafford calls for changes in drug labeling that would better reflect what is and is not known about a drug.

If a new drug or treatment hasn't been tested against existing ones, the label should clearly state so. For example: "Although this drug has been shown to lower blood pressure more effectively than placebo, it has not been shown to be more effective than other members of the same drug class."

This type of labeling should cut down on the marketing and prescribing of new drugs that have no known advantages over current ones, but cost ten times as much. It would also encourage drug developers to test new products against older ones.

Clinical trials comparing a new drug to existing ones require larger numbers of subjects and are more expensive than trials against placebo are. They also pose a greater risk of findings unfavorable to drug developers. These are reasons that such trials are rarely conducted. Stafford's comparative labeling requirement might make such trials more common.

In the U.S., when it comes to drugs, new does not always mean new and improved. Comparative drug labeling could help change this.

The essay was published online by the New England Journal of Medicine on August 12, and is freely available.