Perspective on Drug Hypersensitivity
This issue of QuarterWatch™ focuses on serious hypersensitivity reactions reported to the US Food and Drug Administration (FDA) for therapeutic drugs using data from the most recent 12 months available. It also surveys the newly released case reports for 2013, Quarter 1, and provides an update on the continuing drug safety issues surrounding anticoagulant drugs.
Cases of reported drug hypersensitivity (mostly drug allergies) were identified using a standardized set of medical terms created by the pharmaceutical industry to classify possible cases of adverse drug events occurring in clinical trials or identified through postmarket surveillance. To identify suspect drugs, we screened 147,318 selected cases of serious adverse drug events from March 2012 through March 2013.
- Hypersensitivity was very common, accounting for 13,042 cases (8.9%), and more than any other among 91 adverse reaction categories except non-specific gastrointestinal symptoms. We classified 4,045 of these cases as severe, involving death, disability, or a medical emergency.
- A large and diverse selection of drugs was implicated, with 234 drugs having 10 or more hypersensitivity reports in one year. However, only 87 drugs fell into the subset of the 4,045 most severe cases.
- A sample of prescribing information for health professionals for 20 drugs with 10 or more reported cases of severe hypersensitivity showed all 20 provided information about these reactions, and 14/20 (70%) had prominent warnings.
To highlight drugs with the most frequently reported severe hypersensitivity reactions, cases were divided into four categories: anaphylactic shock, a rapid onset systemic immune reaction; severe cutaneous, widespread skin eruptions that can be life-threatening; angioedema, a localized swelling of lips, tongue, eyelids, or other body parts; and other severe forms of hypersensitivity. The 10 most frequently reported drugs in each category are identified in the report, constituting useful clinical alert lists.
QuarterWatch™ is an independent publication of the Institute for Safe Medication Practices (ISMP). We analyze computer excerpts from the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS). These reports (best known as MedWatch reports) are a cornerstone of the nation’s system for monitoring the safety of prescription drugs after FDA marketing approval.