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Xolair is a popular injectable asthma medication. Its label carries two FDA-mandated warnings, one about anaphylaxis and one related to heart problems and blood vessels in the brain.

Allergists and other physicians routinely prescribe Xolair, manufactured by Genentech, to treat moderate to severe allergic asthma in patients 12 years and older. It is normally reserved for patients who have not responded adequately to high doses of corticosteroids. It is approved for treatment of chronic spontaneous urticaria, better known as chronic hives.

The active substance in Xolair (also known as omalizumab) is actually a monoclonal antibody that helps to block the body's allergic response to certain allergens. Patients receive shots of Xolair every two or four weeks.

Xolair was first approved in 2003 for the treatment of allergic asthma. In 2014, it was also approved for the treatment of chronic hives where there is no known trigger.

Serious side effects of Xolair include heart attacks, mini strokes and anaphylactic reactions, all of which are potentially deadly.

How Xolair Works

Humans have special cells in the body that identify and attack foreign objects like viruses, bacteria, and allergens. These cells are known as antibodies, or immunoglobulin. One type of antibody is known as Immunoglobulin E, or IgE. It plays a key role in the body's allergic responses.

The antibody in Xolair works to stop the allergic response to certain allergens by binding itself to the Immunoglobulin E (IgE). Once it binds itself to the IgE, the response is stopped. When the allergic response is stopped, it stops the body's reaction to the allergens.

For people with allergic asthma, that means the airways stay open when they become exposed to allergens. Over time, this helps keep asthma attack rates down and improves lung function.

The U.S. Federal Drug Administration (FDA) approved new label changes in 2014 in response to a five-year study that showed that patients taking this medication have a higher risk of problems with the heart and vessels that feed blood to the brain.

This medication has several serious side effects. Anaphylaxis is one of the most serious side effects, occurring in one out of every 1000 patients. Other serious side effects include heart attacks, pulmonary hypertension, deep vein thrombosis, chest pain, and an increased potential for cancer development.

Serious side effects

Among the most serious side effect of Xolair is anaphylaxis, a life-threatening allergic reaction that can cause heart attacks, lung airway spasms, drops in blood pressure, fainting or swelling of the throat or tongue.

An anaphylactic reaction can occur up to 24 hours after an injection of Xolair is given. It can occur at the first dose or even after a year or more of treatments.

To keep patients safe, doctors are urged to monitor patients two hours after administering Xolair. They must have the equipment and drugs on hand to treat anaphylaxis symptoms immediately as they can be life threatening. Patients taking Xolair are urged to carry emergency self-treatment medication (Epi-Pens for example) with them in case something happens after they leave the doctor's office.

Patients taking this drug have experienced heart attacks, pulmonary hypertension, deep vein thrombosis, pulmonary embolisms (blood clots) and chest pain after receiving an injection. Some of these incidents have been life threatening.

Studies have shown that patients who have received Xolair to treat asthma may have a higher chance of getting certain kinds of cancer. Those studies also demonstrated that people taking Xolair have a higher risk of certain parasitic infections.

Other side effects

Patients reported less serious side effects while using Xolair also. These included the following:

  • Pain, bruising and swelling at the injection site
  • Recurrent headaches
  • Fatigue
  • Pain in the muscles and joints
  • Dizziness
  • Pain in the ear
  • Loss of hair
  • Itching or mild rash
  • Sore throat
  • Symptoms of a cold

FDA Action

The safety of Xolair has been under constant review since its release. In 2007, the FDA approved changes to the drug label indicating the risk of anaphylaxis. The 2014 changes centered on the heart and brain risks found after a five-year study of adverse events involving use of the drug.

In 2007, the FDA changed the labeling on Xolair to enhance the warnings about anaphylaxis. This stemmed from the potential delay that patients could experience between the injection and the anaphylactic reaction.

In 2014, the FDA approved additional label changes that focused on higher risks of heart problems and the blood vessels in the brain. The new labeling also indicates that some patients were at higher risk of developing certain cancers than the normal population.