Why Are Drugs Recalled?

When a drug is taken off the market, it is not unreasonable to ask why the drug was approved for sale in the first place. After all, aren't drugs supposed to be safe? Did someone make a horrible mistake somewhere along the way?

The US Food and Drug Administration's (FDA) mission is to ensure that drugs are "safe and effective". But what does this really mean? When it comes to drugs, a safe drug is one whose benefit outweighs its risks for its intended use and for the population it is intended to treat. Cancer drugs, for example, tend to be highly toxic, but they also save lives.

All drugs, in fact, have potential adverse effects. When a pharmaceutical company develops a new drug, the FDA approves the drug if the agency deems that its benefits outweigh its risks. And to make such a determination, the FDA reviews results of clinical trials and other tests that are usually conducted over several years.

But despite the rigorous and lengthy testing that a drug undergoes prior to it even being submitted for FDA approval, not all risks and adverse effects of the drug can be known before it is made available on the market. For this reason, drugs continue to be evaluated after their approval.

When the FDA receives reports of serious side effects, it assesses them for their seriousness and the probability that they were caused by the drug. The FDA then compares the efficacy and toxicity of other treatments for the same condition. A determination of whether the benefits of the drug continue to outweigh the risks for the intended condition and population is then made and, if so, the drug continues to be tested and monitored.

If serious problems with the drug are uncovered, the FDA may advise the manufacturer that its use be limited to a narrower population and/or set of diseases or conditions. It may also require labeling changes and notification to doctors and consumers of the new risks uncovered through letters, medication guides, and other education. In certain cases, the FDA will mandate a "black box warning", a labeling change considered the sternest kind of warning of a serious risk or potential adverse effect a drug can receive short of being removed from the market.

If the FDA determines that a drug no longer has a place in treatment, it asks the manufacturer to withdraw it from the market voluntarily. With only one exception in which the drug was withdrawn despite its manufacturer's objection, every company has agreed to do so voluntarily.

When the FDA believes it is clear that a drug no longer has a place in treatment, it will ask the manufacturer to withdraw the drug voluntarily. (See "Safety-Based Drug Withdrawals (1997 - 2001).") Companies have agreed to withdraw the drug in all cases except one--the case of an antidiabetic drug called phenformin, which was taken off the market in 1976 as an imminent hazard, despite the company's objections. If a company does not agree, the FDA can bring formal procedures to require withdrawal.