Omalizumab (Xolair)

What is it text.

Chronic hives are often driven by an antibody called IgE and the immune cells it switches on. Omalizumab is a lab-made antibody that grabs onto free IgE in the blood. This lowers the amount of IgE that can trigger the cells that release histamine and other itch-causing chemicals. With less of this signaling, hives and itching calm down. It can help even when the exact trigger for the hives is unknown.

For chronic hives, the usual dose is 150 mg or 300 mg given as a shot under the skin once every 4 weeks. Unlike its use for asthma, the hive dose is not based on body weight or IgE level. A healthcare provider usually gives the first injections in the office and watches you for a period of time afterward, because a severe allergic reaction is possible. Over time, some patients may be taught to inject at home if their doctor approves. This is educational only. Follow your care team's plan.

• Redness, swelling, or pain where the shot is given
• Headache
• Cold-like symptoms (stuffy nose, sore throat, sinus congestion)
• Joint pain
• Nausea
• Cough

• Anaphylaxis (a severe, whole-body allergic reaction): trouble breathing, a tight throat, dizziness or fainting, a fast heartbeat, swelling of the face or tongue, or hives that suddenly get worse. This is rare (about 1 to 2 in 1,000) but can happen after any dose, even hours later. Call 911 right away.
• Signs of a new infection or fever
• Rare reports of joint pain with a rash

Because of the anaphylaxis risk, early doses are given where staff can treat a reaction. Some patients are given an epinephrine auto-injector to keep on hand.

• Do not use if you have had a severe allergic reaction (anaphylaxis) to omalizumab before.
• Use with caution if you have a history of severe allergies to foods or drugs, as this may raise the risk of a reaction.
• It is not a rescue medicine and does not treat a sudden, severe allergic emergency.