Topic Overview

Omalizumab (Xolair) is a medicine approved by Health Canada and the U.S. Food and Drug Administration (FDA) for use in people age 12 and older who have moderate or severe persistent asthma. This medicine costs a lot more than any of the standard treatments for asthma.

The medicine works by blocking immunoglobulin E (IgE) from attaching to allergens. When IgE attaches to an allergen, it sets off a process that leads to the symptoms of an allergic reaction.

This medicine may help reduce asthma episodes, improve peak expiratory flow (PEF), and reduce the need for other medicines. It may also reduce emergency room visits and hospital stays. But more study is needed.

Omalizumab is given as a shot. The dose depends on your body weight and IgE level.

Your doctor may recommend this medicine if:

• Your asthma is not well controlled after using inhaled corticosteroids and long-acting beta2-agonists or leukotriene pathway modifiers for 3 months. People who use oral or injected corticosteroids or who need high doses of inhaled corticosteroids for daily control can also consider using this medicine.
• You have severe allergic asthma and your symptoms aren't relieved by avoiding allergens or taking other medicines.

Severe allergic reactions, including anaphylaxis, can occur with omalizumab, but this is rare. So people who get this medicine are watched for 2 hours after they get their first 2 doses. They should also carry epinephrine in case they have an allergic reaction after treatment.