Xolair (omalizumab) is a prescription drug used to treat certain conditions, such as asthma or food allergies. The drug comes as an injection. It’s usually given once every 2 or 4 weeks.
Xolair is used to treat the following in adults and certain children:
Xolair is also used to treat chronic (long-term) rhinosinusitis (sinus infection) with nasal polyps in adults only. For this purpose, the drug is used with other medications.
The active ingredient in Xolair is omalizumab. (An active ingredient is what makes a drug work.) Xolair belongs to a group of drugs called monoclonal antibodies. These are made from the immune system cells in the body.
Xolair comes in three forms: a syringe prefilled with solution, an autoinjector prefilled with solution, and 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 Xolair overview.
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.
This Xolair dosing table 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 |
| chronic rhinosinusitis with nasal polyps | based on body weight and level of serum IgE* |
| asthma | based on body weight and level of serum IgE* |
| food allergies | 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.
You should follow 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 syringes and autoinjectors, both prefilled with solution, and vials of powdered medication. (A healthcare professional mixes the powder into a solution.) All forms are for subcutaneous injection, which is given under the skin.
What strengths does Xolair come in?
Xolair syringes and autoinjectors are prefilled with solution in the following strengths, given in milligrams per milliliter (mg/mL):
- 75 mg/0.5 mL
- 150 mg/mL
- 300 mg/2 mL
The vials of powdered medication are available in a strength of 150 milligrams (mg).
What are the usual dosages of Xolair?
Xolair’s dose and frequency vary depending on the condition being treated. For asthma, chronic rhinosinusitis with nasal polyps, and food allergies, doctors use dosage calculator tables to determine the right dose.
The following information describes dosages that are commonly used or recommended for adults. But your doctor will determine the best dosage for your needs.
For children’s dosages of the drug, see the “What’s the dosage of Xolair for children?” section later in this article.
Dosage for chronic urticaria (a certain type of hives)
Xolair’s usual dosage for chronic urticaria is 150 mg or 300 mg every 4 weeks.
Dosage for chronic rhinosinusitis with nasal polyps
Xolair’s dosage for chronic rhinosinusitis with nasal polyps is based on body weight in kilograms (kg) and serum IgE levels. (Serum IgE is a type of antibody in the blood. It’s part of the immune system.) Dosages can range from 75 mg to 600 mg every 2 to 4 weeks.
The doctor will confirm your body weight in kg before you receive the drug. (For reference, 1 kg equals approximately 2.2 pounds [lb].) They’ll also check your serum IgE level with a blood test. Once your 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
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 your body weight in kg before you receive the drug. They’ll also check your serum IgE level with a blood test. Once your doctor has these details, they can determine the specific dosage to prescribe.
Dosage for food allergies
Xolair’s dosage for food allergies is based on body weight in kg and serum IgE levels. Dosages can range from 75 mg to 600 mg every 2 to 4 weeks.
The doctor will confirm your body weight in kg before you receive the drug. They’ll also check your serum IgE level with a blood test. Once your doctor has these details, they can determine the specific dosage to prescribe.
What’s the dosage of Xolair for children?
The following information 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.
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 in kg of the child receiving the drug. 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.
Dosage for food allergies
Xolair is approved to treat food allergies in children ages 1 year and older.
Xolair’s pediatric dosing for food allergies is based on body weight in 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 in kg of the child receiving the drug. 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
Unless you receive Xolair to treat chronic urticaria, 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” earlier)
- 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” earlier in this article.) 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 way to make the injection.
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 its online resource. But if you have severe symptoms, immediately call 911 (or a local emergency number) or go to the nearest emergency room.
Here are answers to some questions commonly asked about Xolair’s dosage.
Is Xolair ever given as more than one injection?
Yes, it is. Your dose may be higher than the strength of the form your doctor prescribes. If so, you’ll need to receive more than one injection for each dose. It’s recommended that you choose a different injection site for each injection that’s at least 1 inch away from other injection sites.
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. Unless you’re receiving Xolair for chronic urticaria, dosages of Xolair 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 related to the conditions Xolair treats. Xolair works by lowering IgE levels. For asthma, chronic rhinosinusitis with nasal polyps, and food allergies, 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.
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.
