Common Side Effects of Xolair (Omalizumab)
The most common side effects of Xolair (omalizumab) include injection site reactions, headache, joint pain, upper respiratory tract infections, and a small but significant risk of anaphylaxis (0.2% of patients). 1, 2
Most Common Side Effects by Condition
In Adults and Adolescents (12+ years) with Asthma:
- Joint pain (especially in arms and legs)
- Dizziness
- Fatigue
- Itching
- Skin rash
- Bone fractures
- Ear pain or discomfort 2
In Children (6-12 years) with Asthma:
- Swelling of the inside of nose, throat, or sinuses
- Headache
- Fever
- Throat infection
- Ear infection
- Abdominal pain
- Stomach infection
- Nose bleeds 2
In Adults with Chronic Rhinosinusitis with Nasal Polyps:
- Headache
- Injection site reactions
- Joint pain
- Upper abdominal pain
- Dizziness 2
In People with Chronic Spontaneous Urticaria (Hives):
- Nausea
- Headaches
- Swelling of the inside of nose, throat or sinuses
- Cough
- Joint pain
- Upper respiratory tract infection 2, 3
In People with Food Allergy:
- Injection site reactions
- Fever 2
Serious Side Effects to Monitor
Anaphylaxis Risk
The most significant serious side effect is anaphylaxis, which occurs in approximately 0.2% of patients receiving Xolair 1. The American Academy of Allergy, Asthma & Immunology/American College of Allergy, Asthma and Immunology Joint Task Force has documented that:
- Most anaphylactic reactions (77%) occur within the first three doses
- 67% of reactions occur within 2 hours of administration
- Some reactions (13%) can occur more than 12 hours after administration 1
Other Serious Side Effects
- Cancer (rare cases observed in some patients)
- Inflammation of blood vessels (rare, especially in patients also taking oral steroids)
- Fever, muscle aches, and rash (typically 1-5 days after injection)
- Parasitic infections (in those at high risk)
- Cardiovascular events (chest pain, heart attack, blood clots, temporary weakness on one side of the body, slurred speech, or altered vision) 2
Administration and Monitoring Protocol
Due to the risk of anaphylaxis, the following safety measures are recommended:
Xolair should be administered in a healthcare setting
Patients should be observed for:
Patients should be:
Clinical Considerations
- Xolair is generally well-tolerated with adverse event rates similar to placebo in clinical trials 5, 6
- The drug has a long half-life (26 days), allowing for infrequent administration (every 2-4 weeks) 5
- Dosing is determined by body weight and pre-treatment serum IgE levels 5
- In studies of chronic urticaria, no significant side effects were observed in some patient populations 7
By understanding these common side effects and implementing proper monitoring protocols, healthcare providers can safely administer Xolair while minimizing risks to patients.