Prescription Medicament Safety

Of the more than two thousand prescription medicaments deemed safe and effective by the FDA virtually all carry some risks. This means that they may fail to work, or have harmful side effects under certain circumstances. Makers of prescription medicaments are required to list all potential adverse reactions. Manufacturers have options. Adverse reactions can be categorized by organ system (heart, lungs, liver, etc.), by severity or frequency, by toxicological mechanisms, or by a combination of these. However, listing adverse reactions does not necessarily mean that they occur frequently. Pharmaceutical manufacturers sometimes list a reaction if it happened in one or two persons out of tens of thousands taking the medicament worldwide. On the other hand, you may personally have a reaction that is not listed.

Before the FDA approves a new medicament for marketing, agency scientists and health professionals work with the product's manufacturer to develop its official labeling. The labeling summarizes the results of scientific research on the product, including studies in humans to assess safety and effectiveness. But these studies, which seldom involve more than a few thousand people, can't generate a perfect picture of how a medicament will behave when it's used by hundreds of thousands or millions of people. As a result, it's often hard to anticipate all adverse effects-those that may occur only once in 10,000 or more uses.

The FDA has in place systems to continue to monitor the safety of approved medicaments after they come into general use. As those systems disclose safety problems, the agency takes corrective action.

In one year, the agency receives some 52,000 medicament-adverse reaction reports, about 10 percent of which come directly from health professionals. Each of these reports is checked against the agency's computerized Adverse Reaction Reports Data Base.

The FDA determines if the problem is occurring frequently, and whether the adverse reaction is described in the product labeling but is being seen more often than expected, or is one that the labeling doesn't even mention.

If adverse reaction reports tied to a specific product accumulate, the FDA is faced with an important question: Is the problem so serious that the product has to come off the market, or can it be dealt with responsibly by adding a warning to the labeling or taking other steps to inform doctors and patients of the need to guard against the hazard?

When isotretinoin (Accutane) was approved in 1982 for treating severe cystic acne unresponsive to other therapy, the labeling warned against its use by pregnant women. Animal studies had shown that the medicament could cause birth defects. Soon after it came into general use, the FDA began to receive reports of human birth defects associated with the medicament. One of every four fetuses exposed to the medicament was injured by it. Clearly, the warning against use by pregnant women was not being well heeded.

The labeling for Accutane was changed several times to strengthen the warning against use in pregnancy. Manufacturers sent letters to physicians emphasizing the risk of fetal damage.

Adverse reaction monitoring and evaluation has identified problems with medicaments, required relabeling and that safety problems be publicized, and enabled valuable medicaments to stay on the market.

In addition to labeling, how else do physicians find out about a medicament? Much of it comes from pharmaceutical company sales personnel, medical journals, and direct mail advertisements.

In a federally funded study, prescription medicament advertisements targeted for physicians were found to be misleading in 66 of the 109 medicament advertisements reviewed. It was determined that medicament advertising for doctors sometimes has misleading headlines and insufficient information on side effects.

How can you obtain more information about a prescription medicament? For example, you can request a "package insert." The FDA tried to get a mandatory patient-package insert program in the early 1980s for ten classes of medicaments. But companies and pharmacists complained that the inserts would require considerable storage space, and constant reprinting due to changes in medical knowledge. These complaints are no longer valid, according to the FDA, because of the rapid expansion of computer technology. Easily updated software could allow pharmacists to print needed patient information while filling a prescription.