The Food and Drug Administration (FDA) has asked the manufacturer of omalizumab (Xolair) to add a black box warning to the labeling. The drug, which is taken for asthma caused by allergies, has been associated with anaphylaxis. The FDA has also requested that a medication guide be included with the packaging. Omalizumab was approved in 2003 for the treatment of adults and adolescents (12 years of age or older) with moderate-to-severe persistent asthma attributable to allergy to pollen, grass, or dust in whom inhaled steroids don't work well.

At the time omalizumab was approved, anaphylaxis had been identified as a possible adverse effect (on the basis of three cases identified in 3,507 patients involved in clinical trials, an incidence of approximately one in 1,000, although retrospective analysis revealed two additional cases). In the 48 postmarketing cases of anaphylaxis after the use of omalizumab reported between June 2003 and December 2005, two issues raised significant concern: first, while most (71%) occurred within the first two hours of administration, 13% occurred as long as 24 hours afterward; second, in a majority of cases (56%), anaphylaxis first occurred after repeated administration, sometimes after two years of treatment with the drug.

Nurses should be prepared for medication-related life-threatening emergencies after the administration of omalizumab. The drug should be administered in a clinician's office and the patient carefully observed for at least two hours for dizziness, labored breathing, tightness of the chest, syncope, hives and itching, and swelling of the mouth and throat, and emergency medication and equipment should be close at hand. Education provided to patients should include guidance in the recognition of the symptoms of anaphylaxis, and they should be given an epinephrine autoinjector (the EpiPen, for example) in case of a later reaction.