Keeping up with drug safety information

FDA Consumer, May-June, 2006 by Michelle Meadows

The Food and Drug Administration approves a drug for marketing after determining that the drug's benefits outweigh the risks for the intended user. But even with a rigorous evaluation process, some safety problems surface only after a drug is used in the wider population.

"No amount of study before marketing will ever reveal everything about a new drug's effectiveness or risks," says Sandra Kweder, M.D., deputy director of the Office of New Drugs in the FDA's Center for Drug Evaluation and Research (CDER). "This is why post-marketing surveillance is extremely important and serves to complement the pre-marketing assessment."

After a drug is on the market, the FDA evaluates reports of safety problems on an ongoing basis. Experts consider such factors as the frequency and seriousness of the problems reported, as well as the seriousness of the disease the drug is meant to treat and whether alternative therapies are available.

"As we find out more about the potential risks or benefits of a drug," Kweder says, "the label may be revised so that it better reflects information on appropriate use of the drug."

The Drug Safety Oversight Board

The FDA's Drug Safety Oversight Board (DSB) was formed in 2005 to make recommendations to the CDER about the management of emerging drug safety issues and to assist in communicating those issues to patients and physicians.

CDER Deputy Director Douglas C. Throckmorton, M.D., serves as chairman of the board. Susan Cummins, M.D., M.P.H., who worked previously in the FDA's Division of Pediatric Drug Development, is the board's executive director. The DSB also includes members from throughout the CDER, as well as experts from other parts of the FDA, the Department of Veterans Affairs, and the National Institutes of Health.

"The board adds an independent perspective to the decision-making process," Kweder says. "It's made up of FDA experts who were not involved in the initial review of the drug, as well as medical experts from other federal agencies." Where appropriate, the DSB can also consult with experts outside of government and representatives of patient and consumer groups.

The DSB is charged with conducting timely and comprehensive evaluations of complex safety issues and with making recommendations to the CDER on how they should be managed and communicated to the public. Members meet roughly every six weeks to discuss emerging drug safety issues and to assist in developing safety policy in the CDER.

An important aspect of their work is weighing the impact of adverse drug reactions against the benefits of a drug, and how best to communicate that balance around emerging safety concerns--even when the FDA is still evaluating data and has not reached a conclusion. "All of these activities help the CDER communicate emerging safety concerns effectively to patients and physicians," Throckmorton says. Some examples of drugs that the DSB has discussed include Tequin (gatifloxacin). In February 2006, after reports of patients who developed abnormal blood sugar levels from the use of Tequin, labeling changes were made to this antibiotic. The changes strengthened warnings about serious cases of low blood sugar and high blood sugar in people taking the drug. Also, a new contraindication was added; Tequin should not be used in people who have diabetes.

Trasylol (aprotinin injection). Trasylol is a drug used to prevent blood loss during surgery. In February 2006, the FDA issued a public health advisory alerting doctors who perform heart bypass surgery that Trasylol has been linked in two scientific publications to a higher risk of kidney problems, heart attacks, and strokes in those who undergo artery bypass graft surgery. The DSB agreed with this course of action, and the FDA has undertaken a full review of the available data before considering what additional steps, if any, are necessary.

Paxil (paroxetine). In December 2005, the FDA's patient information sheet for the antidepressant Paxil was updated to indicate that early results of new studies show the drug increases the risk of birth defects, particularly in the first three months of pregnancy. Because of the risk of untreated depression, it was important to recommend that for some women who have already been taking the drug, the benefits of continuing the drug may be greater than the potential risks to the baby.

Biaxin (clarithromycin). The FDA's patient information sheet for this antibiotic was updated in December 2005. A preliminary analysis of a study in Denmark of people with heart disease showed that clarithromycin use was associated with a higher chance of death from heart problems. After extensive internal analysis and discussion with the DSB, the FDA agreed with the conclusions of the Danish Medicines Agency and has not recommended any changes to the use of the drug at this time.

Evaluating Communication Tools

As part of the agency's commitment to improving communications, the FDA held a public hearing on "CDER's Current Risk Communication Strategies for Human Drugs" in December 2005, in Washington, D.C.