Xolair Dosage

Generic name: omalizumab
Dosage form: injection, solution

This dosage information does not include all the information needed to use Xolair safely and effectively. See full prescribing information for Xolair.

The information at Drugs.com is not a substitute for medical advice. ALWAYS consult your doctor or pharmacist.


Administer Xolair (omalizumab) 150 to 375 mg by subcutaneous (SC) injection every 2 or 4 weeks. Determine doses (mg) and dosing frequency by serum total IgE level (IU/mL), measured before the start of treatment, and body weight (kg). See the dose determination charts below (Table 1 and Table 2) for appropriate dose assignment.

Periodically reassess the need for continued therapy based upon the patient’s disease severity and level of asthma control.

Table 1: Administration Every 4 Weeks: Xolair Doses (milligrams) Administered by Subcutaneous Injection Every 4 Weeks for Adults and Adolescents 12 Years of Age and Older
Pre-treatment Serum IgE (IU/mL) Body Weight (kg)
30-60 > 60-70 > 70-90 > 90-150
≥ 30-100 150 150 150 300
> 100-200 300 300 300
> 200-300 300
> 300-400 SEE TABLE 2
> 400-500
> 500-600


Table 2: Administration Every 2 Weeks: Xolair Doses (milligrams) Administered by Subcutaneous Injection Every 2 Weeks for Adults and Adolescents 12 Years of Age and Older
Pre-treatment Serum IgE (IU/mL) Body Weight (kg)
30-60 > 60-70 > 70-90 > 90-150
≥ 30-100 SEE TABLE 1
> 100-200 225
> 200-300 225 225 300
> 300-400 225 225 300
> 400-500 300 300 375
> 500-600 300 375 DO NOT DOSE
> 600-700 375


Dosing Adjustments

Adjust doses for significant changes in body weight (see Table 1 and Table 2).

Total IgE levels are elevated during treatment and remain elevated for up to one year after the discontinuation of treatment. Therefore, re-testing of IgE levels during Xolair treatment cannot be used as a guide for dose determination.

  • Interruptions lasting less than one year: Dose based on serum IgE levels obtained at the initial dose determination.
  • Interruptions lasting one year or more: Re-test total serum IgE levels for dose determination.

Preparation and Administration

Prepare Xolair for subcutaneous injection using Sterile Water for Injection (SWFI), USP, ONLY. Each vial of Xolair is for single use only and contains no preservatives.


The lyophilized product takes 15-20 minutes to dissolve. The fully reconstituted product will appear clear or slightly opalescent and it is acceptable if there are a few small bubbles or foam around the edge of the vial. The reconstituted product is somewhat viscous; in order to obtain the full 1.2 mL dose, ALL OF THE PRODUCT MUST BE WITHDRAWN from the vial before expelling any air or excess solution from the syringe.

Use the solution within 8 hours following reconstitution when stored in the vial at 2-8ºC (36-46ºF), or within 4 hours of reconstitution when stored at room temperature. Reconstituted Xolair vials should be protected from sunlight.


STEP 1: Draw 1.4 mL of SWFI, USP into a 3  mL syringe equipped with a 1 inch, 18-gauge needle.

STEP 2: Place the vial upright on a flat surface and using standard aseptic technique, insert the needle and inject the SWFI, USP directly onto the product.

STEP 3: Keeping the vial upright, gently swirl the upright vial for approximately 1 minute to evenly wet the powder. Do not shake.

STEP 4: After completing STEP 3, gently swirl the vial for 5-10 seconds approximately every 5 minutes in order to dissolve any remaining solids. There should be no visible gel like particles in the solution. Do not use if foreign particles are present.

Note: If it takes longer than 20 minutes to dissolve completely, repeat STEP 4 until there are no visible gel-like particles in the solution. Do not use if the contents of the vial do not dissolve completely by 40 minutes.

STEP 5: Invert the vial for 15 seconds in order to allow the solution to drain toward the stopper. Using a new 3 mL syringe equipped with a 1-inch, 18-gauge needle, insert the needle into the inverted vial. Position the needle tip at the very bottom of the solution in the vial stopper when drawing the solution into the syringe. Before removing the needle from the vial, pull the plunger all the way back to the end of the syringe barrel in order to remove all of the solution from the inverted vial.

STEP 6: Replace the 18-gauge needle with a 25-gauge needle for subcutaneous injection.

STEP 7: Expel air, large bubbles, and any excess solution in order to obtain the required 1.2 mL dose. A thin layer of small bubbles may remain at the top of the solution in the syringe.


Administer Xolair by subcutaneous injection. The injection may take 5-10 seconds to administer because the solution is slightly viscous. Each vial delivers 1.2 mL (150 mg) of Xolair. Do not administer more than 150 mg per injection site. Divide doses of more than 150 mg among two or more injection sites. (Table 3).

Table 3: Number of Injections and Total Injection Volumes
Xolair Dose
Number of Injections Total Volume Injected
150 1 1.2
225 2 1.8
300 2 2.4
375 3 3.0


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