FRIDAY, Nov. 18, 2005 (HealthDay News) -- Nearly 42 percent of U.S. patients in a recent sampling were receiving prescriptions for drugs with "black-box" warning labels that advise of potential hazards associated with use of the medication, a new study found.
And physicians' compliance with recommendations listed on these black-box warning -- such as ordering additional lab tests -- were variable, said the authors of the study, who published their findings online in the Nov. 18 issue of Pharmacoepidemiology and Drug Safety.
"We need to think about communicating the risks of drugs more effectively," said study author Anita Wagner, an assistant professor of ambulatory care and prevention at Harvard Medical School in Boston.
Black-box warnings indicate the U.S. Food and Drug Administration's highest level of risk on prescription medications. During the recent FDA hearings on cox-2 inhibitors and non-steroidal anti-inflammatory drugs (NSAIDs), much of the debate boiled down to whether or not to recall a drug completely or give it a black-box warning.
In the end, the cox-2 painkiller Celebrex received the warning while two other similar medications, Bextra and Vioxx, were pulled from the market.
According to the study authors, about 1.4 billion prescriptions are written in ambulatory-care settings in the United States each year, and that number is likely to increase.
"New drugs are coming out that can help people greatly, but drugs have risks," Wagner said.
While some 200 classes of drugs (including birth control pills) carry black-box warnings -- which are printed in a black frame in the package insert of a drug, as well as on all promotional materials -- there has been little information on how prescribers' actual practice conforms with recommendations.
In what may be the first large study on the subject, Wagner and her colleagues sought to determine which drugs carried black-box warnings, how frequently these drugs were used, and whether prescribing was in compliance with stated recommendations.
The study was a retrospective look at the records of enrollees in 10 managed-care organizations, conducted over two-and-a-half years. The authors looked at how frequently 216 drugs and/or classes of drugs were used in nearly 930,000 enrollees, and at how consistently 19 drugs with black-box warnings were prescribed to 217,000 enrollees.
"We found that drugs with black-box warnings are used very frequently, with more than 40 percent receiving such drugs," Wagner said.
The most glaring area of noncompliance with recommendations was in the area of lab tests; nearly half (49.6 percent) of all prescriptions that should have been accompanied by a lab test were not. Of these, the most common omissions were recommendations for pregnancy tests when a person started taking a new drug (for example, when a woman started taking the drug acitretin for psoriasis).
Almost 13 percent of patients taking drugs that needed continued lab monitoring did not get such monitoring, the researchers found.
Also, 9 percent of prescriptions were written on the same day as another prescription for a drug that was contraindicated, meaning the combination of the two drugs could be hazardous. These involved methotrexate (a cancer drug) and NSAIDs or ketorolac (for pain relief) with other NSAIDs.
On the other hand, prescribers appeared very careful not to prescribe unsafe medications for women who were pregnant. This happened only 0.3 percent of the time.
Possible ways to improve the situation include more precise wording on the warnings and automated alerts at the point of prescribing and dispensing, the researchers said.
Adding more safeguards at the level of dispensing is not a bad idea at all, said Dr. Jay Brooks, chairman of hematology/oncology at the Ochsner Clinic Foundation in Baton Rouge, La.
"One of the suggestions that is reasonable is when a drug is given by the pharmacy that the pharmacist give the patient the literature in the black-box warning before they take it because they may not have told the doctor about a condition that would be in the black box," he said. "That would force another level of safety to be added."
The authors also recommended that the FDA establish and maintain a list of current black-box warning medications, and clinical circumstances associated with illness and death.
"We need to be clear about the magnitude of risk that justifies a black box warning, and the evidence that underlies the recommendations," Wagner said. "We don't have evidence on what works to communicate drug risk to millions of prescribers and patients. We need to study what effective methods there could be, how to use technology appropriately, especially at the point of prescribing."
More information
Visit the FDA's Office of Drug Safety for more on these issues.
