If you, or someone you care about, take Xolair it may cause shortness of breath instead of relieving your asthma symptoms. Because of continued adverse side effects, the Food and Drug Administration (FDA) has proposed that the manufacturer, Genetech, Inc., modify the package of Xolair with a boxed warning.
Xolair is specifically designed to aid allergy sufferers who have not experienced adequate relief from asthma using more traditional steroid-based medications. However, Xolair has been linked to cases of anaphylaxis in approximately one out of every 1,000 users of the product. Anaphylaxis causes shortness of breath, tightening in the chest, dizziness, fainting, hives, and itching. Any dose of Xolair could lead to anaphylaxis in patients, even if the first dose of the drug caused no adverse reaction. Signs of anaphylaxis in users may not surface until up to 24 hours after using Xolair.