The Relevance of Black Box Warnings
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The black box warning placed on droperidol in 2001 reminded clinicians in the perioperative setting of the impact new labeling could have on healthcare facilities, practitioners, patients, and manufacturers. Information on the warning for droperidol was widely disseminated and discussed throughout the anesthesia community. However there are numerous drugs, several of which are of anesthetic interest, which also carry the Food and Drug Administration's (FDA’s) black box warning that may be unknown to many clinicians. In addition, many patients undergoing surgical procedures may be currently taking one or more drugs with a black box warning. A recent study in 10 U.S. Health Maintenance Organizations showed that over 40% of ambulatory care patients were receiving at least 1 drug with a boxed warning.1 The following is a brief review of FDA’s process and a website that contains information on drugs that carry black box warnings. The FDA requires manufacturers of prescription drugs to provide information on their risk in the contraindications, warnings, precautions, and/or adverse reactions sections of the labeling.2 Serious potential hazards of a drug, as determined by the FDA, may require the addition of a black box warning. There are no written criteria or guidelines as to which events cause the FDA to initiate a boxed warning.1,2 The Code of Federal Regulations, Title 21, Volume 4, defines and describes the need for a black box warning as:
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Prior to a drug being launched, the FDA reviews and carefully scrutinizes adverse events that occur during the research phase. An adverse event is any undesirable experience a patient has using a medical product. Serious adverse events, which are the ones FDA is interested in, include death, life-threatening situations, initial or prolonged hospitalization, and situations requiring medical intervention to prevent permanent damage, disability, and congenital anomaly. Congenital anomalies include birth defects, miscarriage and stillbirth, or birth with cancer or some other serious disease.7 If the drug trials report serious and unexpected drug events, then the FDA will make a decision to continue the studies and/or approve the drug. Many times serious or life-threatening adverse events (reported through adverse drug reports (ADRs) are discovered only after a drug has been on the market for years. These serious side effects surface as the drug is more widely used or is prescribed for off-label uses. The research studies performed prior to approval may not find the adverse effects that occur long after the drug is discontinued or that occur only after years of continuous or chronic use. In 1 study, only half of newly discovered serious ADRs were identified and documented within 7 years after drug approval.6 These risks may appear to be life-threatening, or they may appear to be less serious. At this point, the FDA and the drug's sponsor will review new, emerging safety information to determine if there is a true safety issue related to the drug and if regulatory or other action is needed. Once an adverse event or product problem is identified, the FDA can take any of the following actions:
Most drugs, prescriptions and non-prescription, have risks associated with their use. Prescribers must consider these risks and the drug’s benefits when determining drug therapy for the patient. The boxed warning of a drug has been considered by some courts as adequate warning to prescribers of a drug’s risk, and therefore protects the manufacturer from product liability.2 Understanding black box warnings for drugs may help the clinician evaluate the optimal drug regimen for patients. The Drug Information Center under the direction of Joyce Generali MS, RPh, at Kansas University Medical Center has a helpful and easy to use web page to provide black box warning information: www.formularyproductions.com/master/showpage.php?dir=blackbox&whichpage=238. The drugs are categorized by a comprehensive list, alpha index, and by therapeutic class. It is very difficult for clinicians to keep informed of the many black box warnings. This website can help inform practitioners on current and important drug safety information.
References
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