Introduction
Xolair (omalizumab) is a prescription medicine used to treat chronic hives that are not controlled by antihistamines. It is an injectable medicine that needs to be given in a physician’s office. It is usually given once a month. Xolair is a monoclonal antibody that binds to the allergy antibody IgE and forms a complex which is then eliminated from the body. Xolair binds to the allergy antibody before it attaches to an allergy cell called a MAST cell. It also reduces the IgE receptors on the surface of MAST cells. The end result is less MAST cell activation, and fewer hives.
Indications
Xolair is indicated for people 12 years of age and older who have had hives for at least 6 weeks. The first line treatment for hives is a non-sedating/low sedating antihistamine such as Zyrtec, Allegra, or Claritin. The dose of the low/non-sedating antihistamine can be increased fourfold if needed. If there is an inadequate response, then Xolair would be the next recommended step.
Benefits
Chronic hives/swelling have a significant impact on the individual, dramatically decrease the quality of life. People with chronic hives may have also been previously treated with various anti-inflammatory medicines with multiple side effects. Xolair has been approved for the treatment of chronic hives since 2014. Approximately 3/4 of patients with chronic urticaria, improve with Xolair, some very dramatically. One study showed that half of patients have complete resolution of the hives. In some patients, a response can be seen as early as one day, though other people may take several months to respond.
Safety
Xolair is one of the safest biologically engineered medicine available, certainly much safer than oral corticosteroids. The major safety risk is a severe allergic reaction called anaphylaxis, which occurs in a very small number of patients. The risk of anaphylaxis some Xolair is much less than the risk from allergy shots. Symptoms of anaphylaxis might include one or more of the following: wheezing, hives, swelling, low blood pressure, breathing. difficulties. The severe allergic reactions can occur anywhere in the course of Xolair. Other very rare side effects include eosinophil conditions, arthritis/arthralgia, rash, fever, lymphadenopathy, cardiac adverse events, problems involving the heart and blood vessels supplying the brain, and malignancy. Please see the package insert for more details.
