If you have asthma, hives, or nasal polyps, your doctor might suggest Xolair as a treatment option for you. It’s a prescription drug used to treat the following conditions:
- chronic urticaria (a certain type of hives sometimes called chronic spontaneous urticaria); approved for use in adults and certain children
- nasal polyps, to be used in combination with other medications; approved for use in adults
- moderate to severe asthma that’s related to allergies and persists even with other treatments; approved for use in adults and certain children
The active ingredient in Xolair is omalizumab. (An active ingredient is what makes a drug work.) Xolair belongs to a class of drugs called monoclonal antibodies. (These are made from the immune system cells in the body.)
Xolair comes in two forms. One is a prefilled syringe of solution, and the other is a vial of powdered medication. (A healthcare professional mixes the powder into a solution.) Both forms are for subcutaneous injection, which is given under the skin.
This article describes the dosages of Xolair, as well as its strengths and how it’s given. To learn more about Xolair, see this in-depth article.
Note: This article covers Xolair’s usual dosages, which are provided by the drugmaker. But your doctor will prescribe the Xolair dosage that’s right for you.
Note: Xolair’s dosing chart below highlights the basics of Xolair’s dosage for the conditions it treats. Be sure to continue reading beyond the table for more detail.
| Condition | How dosage is determined |
| chronic urticaria | using drugmaker’s recommendation |
| nasal polyps | based on body weight and level of serum IgE* |
| moderate to severe asthma† | based on body weight and level of serum IgE* |
* Serum IgE is a type of antibody (a protein) in the blood. It’s part of the immune system.
† This condition must be related to allergies and persist even with other treatments.
You should use the dosage your doctor prescribes for you. They’ll recommend the dose and dosing schedule that’s best for your condition.
What are the forms of Xolair?
Xolair is available as prefilled syringes of solution and vials of powdered medication. A healthcare professional mixes the powder into a solution. Both forms are for subcutaneous injection, which is given under the skin.
What strengths does Xolair come in?
Xolair prefilled syringes of solution are available in strengths of 75 milligrams (mg) and 150 mg. The vials of powdered medication are available in a strength of 150 mg.
What are the usual dosages of Xolair?
Xolair’s dose and frequency vary depending on the condition being treated. For asthma and nasal polyps, doctors use dosage calculator tables to determine the right dose.
The information below describes dosages that are commonly used or recommended. But your doctor will determine the best dosage to fit your needs.
Dosage for chronic urticaria (a certain type of hives) in adults
Xolair’s usual dosage for chronic urticaria is 150 mg or 300 mg every 4 weeks.
Dosage for nasal polyps in adults
Xolair’s dosage for nasal polyps is based on body weight in kilograms (kg) and serum IgE levels. Dosages can range from 75 mg to 600 mg every 2 to 4 weeks.
The doctor will confirm the body weight of the adult receiving the drug. (For reference, 1 kg equals approximately 2.2 pounds [lb].) They’ll also check the adult’s serum IgE level with a blood test. Once the doctor has these details, they can determine the specific dosage to prescribe.
For this condition, you’ll use Xolair in combination with other medications.
Dosage for asthma in adults
Xolair’s dosage for asthma* is based on body weight in kg and serum IgE levels. Dosages can range from 75 mg to 375 mg every 2 to 4 weeks.
The doctor will confirm the body weight of the adult receiving the drug. (For reference, 1 kg equals approximately 2.2 pounds [lb].) They’ll also check the adult’s serum IgE level with a blood test. Once the doctor has these details, they can determine the specific dosage to prescribe.
* Xolair is approved for use in moderate to severe asthma. It must be related to allergies and persist even with other treatments.
What’s the dosage of Xolair for children?
The information below describes dosages that are commonly recommended for children.
Dosage for chronic urticaria
Xolair is approved to treat chronic urticaria in children ages 12 years and older. The usual dosage is 150 mg to 300 mg every 4 weeks.
Dosage for asthma
Xolair is approved to treat asthma in children ages 6 years and older. Specifically, it’s used for moderate to severe asthma that’s related to allergies and persists even with other treatments.
Xolair’s pediatric dosing for asthma is based on body weight in kg and serum IgE levels. Dosages can range from 75 mg to 375 mg every 2 to 4 weeks.
The doctor will confirm the body weight of the child receiving the drug. (For reference, 1 kg equals approximately 2.2 pounds [lb].) They’ll also check the child’s serum IgE level with a blood test. Once the doctor has these details, they can determine the specific dosage to prescribe.
Is Xolair used long term?
Yes, Xolair is usually used as a long-term treatment. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely use it long term.
Dosage adjustments
If you use Xolair for asthma or nasal polyps, body weight is a factor in determining your dosage. Your doctor may need to adjust your dosage If your body weight changes significantly.
The dosage of Xolair you’re prescribed may depend on several factors. These include:
- the type and severity of the condition you’re using the drug to treat
- your age
- your body weight (see “Dosage adjustments” just above)
- your serum levels of IgE*
* Serum IgE is a type of antibody (a protein) in the blood. It’s part of the immune system.
Xolair is given as a subcutaneous injection. This means the injection is given under the skin, but not into a muscle.
Xolair has a boxed warning about anaphylaxis, which is a life threatening allergic reaction. (See the “Boxed warning: Risk of anaphylaxis” section above.) Due to the risk of anaphylaxis, you’ll get your first few doses of Xolair in a doctor’s office or another healthcare setting. This will allow a healthcare professional to monitor you for symptoms of anaphylaxis. If you have any, they can quickly respond with appropriate treatment.
After several doses, your doctor may decide it’s safe for you or a caregiver to give the injections. In this case, a healthcare professional will show you the proper injection procedure.
Accessible drug labels
If you find it hard to read the prescription label on your medication, tell your doctor or pharmacist. Some pharmacies provide medication labels that:
- have large print or use braille
- feature a code you can scan with a smartphone to change the text to audio
Check your pharmacy for these accessibility features. If yours doesn’t offer them, your doctor or pharmacist might recommend pharmacies that do.
You may get Xolair injections at a doctor’s office or another healthcare setting. If so and you miss an appointment, call as soon as possible to reschedule it. If you’re injecting Xolair at home and miss a dose, call your doctor’s office. They can help you determine when to inject the next dose.
If you need help remembering your next Xolair injection, try using a medication reminder. This can include setting an alarm or downloading a reminder app on your phone.
Do not inject more Xolair than your doctor prescribes, as this can lead to serious side effects.
What to do in case you use too much Xolair
Call your doctor right away if you think you’ve injected too much Xolair. You can also call 800-222-1222 to reach America’s Poison Centers or use the online resource. But if you have severe symptoms, immediately call 911 (or a local emergency number) or go to the nearest emergency room.
Below are answers to some questions commonly asked about Xolair’s dosage.
Is Xolair ever given as more than one injection?
Yes, it is. The maximum recommended injection into one site or area is 150 milligrams (mg). For a dose of more than 150 mg, doctors typically divide it into multiple injections. Usually this will be two or more injections.
Ask your doctor if you have questions about how many Xolair injections you’ll need.
Do I need a blood test before starting Xolair?
Yes, depending on the condition Xolair is treating. Dosages of Xolair for moderate to severe asthma* and nasal polyps are based on body weight and serum IgE level. In this case, you’ll need a blood test before starting the drug.
IgE is an antibody (a protein) that’s part of the immune system. IgE causes the inflammation in nasal polyps. It also causes asthma related to allergies. Xolair treats both conditions by lowering IgE levels. The dose you need will depend on how high your IgE levels are before treatment.
If you have questions about your dosage or using IgE in calculating it, talk with your doctor.
* This condition must be related to allergies and persist even with other treatments.
The sections above describe the usual dosages provided by the drugmaker. If your doctor recommends Xolair for you, they’ll prescribe the dosage that’s right for you.
Remember, you should not change your dosage of Xolair without your doctor’s recommendation. Only use Xolair exactly as prescribed. Talk with your doctor if you have questions or concerns about your current dosage.
Here are some examples of questions you may want to ask your doctor:
- Should my dosage change if Xolair isn’t working well enough for me?
- If I lose or gain weight, will I need a different dosage of Xolair?
- Would it be safe for me to inject Xolair doses at home?
To learn more about Xolair, see these articles:
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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
