Anti-IgE is a form of treatment for allergic conditions that has been approved for the treatment of moderate to severe persistent asthma. Anti-IgE interferes with the function of IgE. IgE is an antibody in the immune system.

How does anti-IgE work?
What anti-IgE medicine is available now?
Are there any side effects or adverse reactions to Xolair®?
What's the safest way to get anti-IgE injections?


How does anti-IgE work?

IgE tells immune cells to initiate allergic reactions. This may bring on symptoms such as coughing, wheezing, nasal congestion, hives and swelling. Anti-IgE attaches to IgE in the blood and helps prevent the allergic reaction.


Primary actions of the Anti-IgE MAb


What anti-IgE medicine is available now?

Xolair® (omalizumab) is the anti-IgE medicine now available. Xolair® is approved by the FDA for use with patients over 12 years of age who:

  • Have poorly controlled moderate to severe persistent asthma,
  • Have year round allergies and
  • Are taking routine inhaled steroids.

Xolair has recently been approved for patients over 12 years of age who:

  • Have chronic idiopathic urticaria (CIU; chronic hives without a known cause) who continue to have hives that are not controlled by conventional treatment such as antihistamines or leukotriene modifying agents.

Xolair® has been shown to decrease asthma episodes in some of these patients.

Xolair® is given by a shot (injection) one to two times a month. The shots are given in the doctor’s office. The dosage varies, depending on the person's weight and IgE blood level. Xolair® is a long-term control medicine. This means it is given routinely to prevent asthma symptoms. It is not a quick relief medicine. Some patients improve quickly. Some patients show a gradual benefit. Xolair® does not appear to work for all patients.



Are there any side effects or adverse reactions to Xolair®?

Common side effects of Xolair® include a reaction at the injection site, viral infections, upper respiratory tract infection, sinusitis, headache and sore throat. These side effects were about as common in patients who received placebo injections.

Several rare, yet severe side effects were reported in the original studies. They include malignancy and anaphylaxis

In the initial studies, cancers  (including breast, skin, prostate, and salivary gland) were seen in 0.5% of patients treated with Xolair®. The rate was 0.2% in patients treated with the placebo dose.

In the initial studies, anaphylaxis was seen in less than 0.1% of the patients treated with Xolair. Since Xolair® was approved in June 2003 additional reports of anaphylaxis have been reported to the FDA.  Information was gathered from about 39,500 patients treated with Xolair. The serious reactions occurred in at least 1 of every 1,000 patients. The reactions these patients had included combinations of symptoms of anaphylaxis.

Symptoms of anaphylaxis include:
  • Increased trouble breathing, coughing, chest tightness or wheezing
  • Dizziness, fainting, rapid or weak heartbeat
  • Swelling in the mouth and throat or trouble swallowing
  • Flushing, itching, hives or a feeling of warmth
  • Vomiting, diarrhea, or stomach cramping.

Although rare, an anaphylaxis reaction can be serious and life-threatening. An anaphylactic reaction may occur with the first dose or after any dose of Xolair®. The reaction may occur soon after the shot is given. It may also occur 24 hours or more after the shot is given.


What's the safest way to get anti-IgE injections?

Although anaphylaxis is rare several steps improve the patient's safety when receiving Xolair®

  • The Xolair® shots are given in the doctor’s office.
  • The patient will need to stay at the doctor’s office for 2 hours after the initial 3 shots are given. After the initial 3 shots the patients will need to stay in the doctor's office for 1 hour after the shot is given.
  • The doctor’s office should be ready to treat an anaphylactic reaction.
  • The patient will be instructed in the use of an epinephrine auto-injector. This is an easy-to-give shot that the patient can use if having an anaphylactic reaction after leaving the doctor’ office.
  • The patient should wear a Medic-Alert bracelet.
  • If you feel you are having an anaphylactic reaction, you need to get medical help right away.

Although anaphylaxis is very rare these are a number of steps that can increase the patient’s safety when receiving anti-IgE treatment.

Remember to talk with your doctor if you have any questions.


This information has been approved by Ronina Covar, MD and Ann Mullen, RN, MSN, CNS, AE-C (April 2014).