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Omalizumab (Subcutaneous)

Medically reviewed by Last updated on Jan 11, 2023.

Subcutaneous route(Powder for Solution;Solution)

AnaphylaxisAnaphylaxis presenting as bronchospasm, hypotension, syncope, urticaria, and/or angioedema of the throat or tongue, has been reported to occur after administration of omalizumab. Anaphylaxis has occurred as early as after the first dose of omalizumab, but also has occurred beyond 1 year after beginning regularly administered treatment. Because of the risk of anaphylaxis, initiate omalizumab therapy in a healthcare setting and closely observe patients for an appropriate period of time after omalizumab administration. Health care providers administering omalizumab should be prepared to manage anaphylaxis which can be life-threatening. Inform patients of the signs and symptoms of anaphylaxis and instruct them to seek immediate medical care should symptoms occur. Selection of patients for self-administration of omalizumab should be based on criteria to mitigate risk from anaphylaxis .

Commonly used brand name(s)

In the U.S.

  • Xolair

Available Dosage Forms:

  • Solution
  • Powder for Solution

Therapeutic Class: Antiasthma

Pharmacologic Class: Monoclonal Antibody

Uses for omalizumab

Omalizumab injection is used to treat moderate to severe persistent allergic asthma. It is used when a patient's asthma has not been controlled sufficiently on other asthma medicines. Omalizumab will not relieve an asthma attack that has already started. Your doctor will perform a skin or blood test to check if you have allergies to year-round allergens.

Omalizumab injection is also used to treat nasal polyps in patients who have tried other medicines (eg, nasal corticosteroids) but they did not work well enough.

Omalizumab injection is also used to treat chronic idiopathic urticaria (CIU) in patients who continue to have hives that are not controlled by an antihistamine (allergy medicine).

Omalizumab is a medicine called an IgE blocker. IgE is short for immunoglobulin E, a substance that occurs naturally in the body in small amounts. This substance plays an important role in allergic asthma. When people with allergic asthma breathe in a year-round allergen, such as cat or dog dander, their bodies make more IgE. This may cause a series of reactions in your body that can lead to asthma attacks and symptoms. Omalizumab works by helping to block IgE.

Omalizumab is to be given only by or under the direct supervision of your doctor.

Before using omalizumab

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For omalizumab, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to omalizumab or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies on the relationship of age to the effects of omalizumab injection to treat asthma in children younger than 6 years of age, nasal polyps in children, and chronic idiopathic urticaria in children younger than 12 years of age have not been performed. Safety and efficacy have not been established.


Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of omalizumab injection in the elderly.


There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Interactions with food/tobacco/alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems

The presence of other medical problems may affect the use of omalizumab. Make sure you tell your doctor if you have any other medical problems, especially:

  • Allergy to latex or
  • Asthma attack or
  • Bronchospasm (breathing problem), acute or
  • Other allergic conditions (besides asthma)—Should not be used in patients with these conditions.
  • Cancer, or history of or
  • Parasite infection, or history of—Use with caution. May make these conditions worse.

Proper use of omalizumab

A nurse or other trained health professional will give you or your child omalizumab in a medical facility. It is given as a shot under your skin, usually in the upper arms, stomach, or thighs.

Omalizumab comes with a Medication Guide and patient instructions. Read and follow these instructions carefully. Ask your doctor or pharmacist if you have any questions.

If you are receiving omalizumab for asthma or nasal polyps, you will receive omalizumab once every 2 or 4 weeks. Your dose will be determined by your IgE level, which your doctor will measure with a simple blood test before treatment begins, and your body weight. Based on your dose, your doctor will also tell you if you will need 1, 2, or 3 injections per dose. If you need more than 1 injection, each will be given in a different place on your body.

Omalizumab is not a rescue medication and should not be used to treat sudden asthma attacks. It is not a substitute for the medicines you are already taking. Never suddenly stop taking, or change the dose of your steroid medicine (inhaled or taken by mouth) unless your doctor tells you to do so.

If you are receiving omalizumab for chronic idiopathic urticaria, you will receive omalizumab every 4 weeks.

Omalizumab injection may also be given at home to patients who have received at least 3 doses of omalizumab under the supervision of a doctor. If you are using omalizumab at home, your doctor or nurse will teach you how to inject the medicine. Be sure that you understand exactly how to use this.

If you use omalizumab at home, you will be shown the body areas where this shot can be given. Use a different body area each time you give yourself a shot. Keep track of where you give each shot to make sure you rotate body areas. This will help prevent skin problems. Do not inject into scars, moles, or skin areas that are red, bruised, tender, hard, or not intact.

Allow the prefilled syringe to warm to room temperature for 15 to 30 minutes before using it. Do not warm the medicine in any other way.

Check the liquid in the prefilled syringe. It should be clear and colorless to pale brownish yellow. Do not use omalizumab if it is cloudy, discolored, or if you see particles in it.


The dose of omalizumab will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of omalizumab. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For injection dosage form (prefilled syringe):
    • For asthma:
      • Adults and children 12 years of age and older—Dose is based on IgE level and body weight, and must be determined by your doctor. The dose is usually 150 to 375 milligrams (mg) injected under your skin every 2 or 4 weeks. Your doctor may adjust your dose as needed and tolerated.
      • Children 6 to younger than 12 years of age—Dose is based on IgE level and body weight, and must be determined by your doctor. The dose is usually 75 to 375 mg injected under your skin every 2 or 4 weeks. Your doctor may adjust your dose as needed and tolerated.
      • Children younger than 6 years of age—Use and dose must be determined by your doctor.
    • For nasal polyps:
      • Adults—Dose is based on IgE level and body weight, and must be determined by your doctor. The dose is usually 75 to 600 milligrams (mg) injected under your skin every 2 or 4 weeks. Your doctor may adjust your dose as needed and tolerated.
      • Children—Use and dose must be determined by your doctor.
    • For chronic idiopathic urticaria:
      • Adults and children 12 years of age and older—150 or 300 milligrams (mg) injected under your skin every 4 weeks. Your doctor may adjust your dose as needed and tolerated.
      • Children younger than 12 years of age—Use and dose must be determined by your doctor.

Missed dose

Omalizumab needs to be given on a fixed schedule. If you miss a dose or forget to use your medicine, call your doctor or pharmacist for instructions.


Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Store in the refrigerator. Do not freeze.

Protect the medicine from direct light. Keep the medicine in the original carton until you are ready to use it. Throw away any unused medicine after 4 hours of removing from the refrigerator. Do not use if the prefilled syringe has been frozen.

Throw away used prefilled syringes in a sharps disposal container or in a hard, closed container where the needles cannot poke through. Keep this container away from children and pets.

Precautions while using omalizumab

It is very important that your doctor check your or your child's progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to receive it. Blood tests and other exams may be needed to check for unwanted effects.

If you stop receiving omalizumab injections, your symptoms can be expected to return.

You may not see immediate improvement in your asthma after omalizumab treatment begins. It takes time for the medicine to work. It is important to continue your omalizumab injections until your doctor tells you otherwise.

Omalizumab may cause a serious type of allergic reaction called anaphylaxis, which can be life-threatening and requires immediate medical attention. Anaphylaxis may occur right away or up to 4 days after receiving omalizumab. Tell your doctor right away if you or your child have a rash, cough, chest tightness, trouble breathing, lightheadedness, dizziness, fainting, rapid or weak heartbeat, anxiety, flushing, itching, hives, feeling warm, swelling of the throat or tongue, throat tightness, hoarseness, or trouble swallowing after receiving omalizumab.

A rare but serious condition called eosinophilia (increased white blood cells in the body) may occur while you are receiving omalizumab. A condition called vasculitis (inflammation of the blood vessels) may also be present. Eosinophilia can be serious and requires immediate medical attention. Tell your doctor right away if you or your child have worsening lung symptoms, rash or bruising of the skin, fever, chest pain, or burning, tingling, or numbness in the hands and feet after receiving omalizumab.

Your doctor will ask you or your child to remain at the healthcare facility or clinic for at least 2 hours after each injection to watch for immediate side effects that can be serious.

Some patients who are receiving omalizumab may have fever, rash, or muscle or joint pain. Tell your doctor right away if you or your child have any of these symptoms.

Using omalizumab may increase your risk of getting certain cancers or infections. Talk to your doctor if you or your child have concerns about this risk.

The needle cap of the prefilled syringe contains dry natural rubber (a derivative of latex), which may cause allergic reactions in people who are sensitive to latex. Tell your doctor if you have a latex allergy before receiving omalizumab.

Before you have any medical tests, tell the medical doctor in charge that you are taking omalizumab. The results of some tests may be affected by omalizumab.

Omalizumab side effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

Less common

  • Blistering, crusting, irritation, itching, or reddening of the skin
  • body produces substance that can bind to drug making it less effective or cause side effects
  • difficulty in moving
  • muscle pain or stiffness
  • pain in the joints
  • stomach pain


  • Cough
  • difficulty with swallowing
  • dizziness
  • fast heartbeat
  • hives, itching, or skin rash
  • malignant tumor
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • tightness in the chest
  • unusual tiredness or weakness

Incidence not known

  • Black, tarry stools
  • bleeding gums
  • blood in the urine or stools
  • chest pain
  • chills
  • fever
  • painful or difficult urination
  • pinpoint red spots on the skin
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • swollen glands
  • unusual bleeding or bruising

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Bleeding, blistering, burning, coldness, discoloration of skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site
  • body aches or pain
  • cold or flu-like symptoms
  • congestion
  • dryness or soreness of the throat
  • headache
  • hoarseness
  • leg pain
  • lumps
  • pain or tenderness around the eyes and cheekbones
  • stuffy or runny nose
  • voice changes

Less common

  • Arm pain
  • cracked, dry, or scaly skin
  • earache

Incidence not known

  • Hair loss

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Frequently asked questions

View more FAQ

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.