Drugs approved by FDA not always safe for all

Whether a medication's benefits outweigh potential risks will become an even greater issue as the population ages and the number of new formularies increases.

By Susan J. Landers, AMNews staff. Nov. 4, 2002. Additional information

Washington -- Although physicians and even some patients realize that no drug is 100% safe, they don't always focus on just how much is unknown about a drug even after it is approved by the Food and Drug Administration for use by the general population.

When a drug is approved, the FDA is saying, "the risk is reasonable given the potential benefit for the population that was studied and for the condition that was studied," said Nancy Smith, PhD, director of training and communications at the agency's Center for Drug Evaluation and Research.

Dr. Smith was speaking at a conference on medication safety held Oct. 17 in Bethesda, Md.

"Once a drug is on the market, you go from a population of a couple of thousand at most, to a population of millions of people who are taking these products. And things are going to show up that never could have been predicted in clinical trials," she said. While a large clinical trial may mean that a new drug is being tested on 2,000 to 3,000 people, an adverse event may show up only after 5,000 people use the medication.

New drugs are tested on only 2,000 people.

After a drug is approved, it may be prescribed for patients who are older than participants in the trial or for patients who use additional medications. "We may be in an unknown area where we don't know if the benefits outweigh the risks," Dr. Smith said.

It's also possible that there may be more benefit and less risk carried by a new drug, but that is also an unknown, said Dr. Smith. While off-label use of a drug is certainly not discouraged, she said, physicians should be aware that such use means venturing into unknown territory.

The FDA's track record indicates that about 2% of approved products have subsequently been taken off the market during the last 10 to 15 years because of conditions that weren't foreseen at the time of approval, she noted. However, that number may increase as more drugs become available, the aging population is prescribed multiple drugs and managed care limits the amount of time physicians can spend with patients explaining possible adverse effects.

A look at labels

For all those reasons the problem of drug safety is likely to get worse, said Dr. Smith. The safety of medications, as well as that of medical devices and the nation's blood supply, has caught the interest of the Healthy People 2010 project, which adopted medical product safety as one of 50 health goals for the nation to achieve in the first decade of the new century.

The responsibility for meeting that goal is shared by government regulators, physicians and other health care professionals, product manufacturers and patients, Dr. Smith said.

For its part, the FDA has embarked on a program to improve the information in the drug labels that accompany prescription medication.

During the last decade, 2% of previously approved drugs have been taken off the market.

A study carried out last fall by the FDA and the National Assn. of Boards of Pharmacy measured information that was provided with prescriptions at about 400 randomly selected pharmacies. Directions and precautions included were rated for accuracy and effectiveness by other pharmacists and for legibility and comprehensibility by a panel of consumers.

The good news was that information was provided in nearly 90% of cases, said Dr. Smith. But it was questionable how good that information was, she said. On a scale of one to 100, the expert pharmacists rated the information at 50 or 60. "When I was in school," said Dr. Smith, "60% was a D at best and that's not very good."

Another survey is planned for 2006 and pharmaceutical companies will have between now and then to improve the label information.

The conference was sponsored by the Peter Lamy Center for Drug Therapy and Aging at the University of Maryland in Baltimore and the National Council on Patient Information and Education.

ADDITIONAL INFORMATION:

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CDER, the FDA's Center for Drug Evaluation and Research (http://www.fda.gov/cder/)

Peter Lamy Center on Drug Therapy and Aging, at the University of Maryland School of Pharmacy (http://www.pharmacy.umaryland.edu/lamy/)

Talk about Prescriptions, a coalition effort from the National Council on Patient Information and Education (http://www.talkaboutrx.org/)

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