Xolair (omalizumab) is a brand-name prescription medication. The Food and Drug Administration (FDA) has approved it to treat certain conditions, such as:
- nasal polyps in adults, if certain other medications did not provide complete relief
- moderate to severe asthma that’s long lasting in certain adults and children ages 6 years and older
- chronic (long-term) hives with an unknown cause in adults and children ages 12 years and older
For more details about Xolair’s uses, including its limitations of use, see this article.
Xolair may be taken long term if you and your doctor decide it’s working well for you.
Here are some fast facts about Xolair:
- Active ingredient: omalizumab, which is a biologic
- Drug class: monoclonal antibody
- How it’s given: subcutaneous injection by:
- your doctor or another healthcare professional, or
- a caregiver or yourself, if your doctor recommends it
As with other drugs, Xolair injections can cause side effects (also known as adverse effects). Read on to learn about potential common, mild, and serious side effects. For a general overview of Xolair, including details about its uses, see this article.
Xolair shots can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.
These are just a few of the more common side effects reported by people who took Xolair in clinical trials. These side effects can vary depending on your age and which condition the drug is being used to treat.*
More common side effects of Xolair include:
- pain, such as joint pain
- dizziness
- fatigue
- reactions at the injection site
- headache†
* For details about the common side effects in children taking Xolair for asthma, see “Side effects in children” below.
† For more information about this side effect, see “Side effect specifics” below.
Mild side effects can occur with Xolair use. These may vary based on the condition you are taking Xolair to treat. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Xolair’s prescribing information.
Mild side effects that have been reported in adults and children ages 12 years and older taking Xolair to treat asthma include:
- pain, which may be felt throughout your body, including your joints, arms, and legs
- fatigue
- dizziness
- skin rash
- itchy skin
- earache
- reactions at the injection site
- headache*
- mild allergic reaction†
Mild side effects that have been reported in people taking Xolair to treat nasal polyps include:
- dizziness
- pain in your joints
- pain in your upper abdomen
- reactions at the injection site
- headache*
- mild allergic reaction†
Mild side effects that have been reported in adults and children ages 12 years and older taking Xolair to treat hives include:
- pain in your joints
- nasopharyngitis (the common cold)
- upper respiratory infection
- sinusitis (inflammation in your sinuses)
- nausea
- cough
- reactions at the injection site
- hair loss*
- headache*
- mild allergic reaction†
These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.
Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking Xolair and want to tell the FDA about it, visit MedWatch.
* For more information about this side effect, see “Side effect specifics” below.
† A mild allergic reaction may occur. However, a more severe allergic reaction is also possible. Xolair has a
Xolair may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Xolair’s prescribing information.
If you develop serious side effects while taking Xolair, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.
Serious side effects that have been reported and their symptoms include:
- Risk of heart and blood circulation problems, such as blood clots, stroke, and heart attack. Symptoms can include:
- pain in your chest or one of your legs
- leg and arm weakness on one side of your body
- slurred speech or being unable to speak clearly
- changes in your vision
- Parasitic worm infection. Symptoms may not always occur, but they can include:
- diarrhea or vomiting
- abdominal pain
- fever
- slowed growth in children
- Immune system reaction. Symptoms can include:
- joint pain
- fever
- inflamed (swollen) lymph nodes
- issues with heart function
- Bone fractures (breaks).
- Severe allergic reaction.*†
- Cancer*
* For more details on this side effect, see “Side effect specifics” section below.
† Xolair has a
Among other uses, Xolair is used to treat a certain form of asthma in children ages 6 years and older.
The following side effects were commonly reported in children ages 6 to 11 years old who took Xolair for asthma:
- nasopharyngitis (the common cold)
- headache
- fever
- ear infection
- strep throat (sore throat from a bacterial infection)
- viral gastroenteritis (the stomach flu)
- pain in their upper abdomen
- bloody nose
- bug bites
If you’re concerned about the side effects your child may experience while taking Xolair, talk with their doctor. They can recommend ways to avoid or help ease your child’s side effects.
Xolair may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.
Are there any long-term side effects of Xolair?
Xolair’s more common side effects are usually temporary. For example, if you have injection site reactions, they should go away within a few days.
However, some of the rare, serious side effects of Xolair may have long-term consequences. For example, if you develop cancer or have bone fractures (breaks) during Xolair treatment, these conditions can affect you for a long time, even after Xolair treatment is stopped.
If you experience side effects that do not go away or ease with time, talk with your doctor. They can recommend ways to relieve them. If these side effects do not ease or go away, or you cannot tolerate them, your doctor can discuss other possible treatment options with you.
Does Xolair treatment cause weight gain or weight loss as a side effect?
No. Changes in body weight were not reported as a side effect of Xolair.
However, your doctor will determine your Xolair dosage based on body weight, among other factors. If you lose or gain weight while you’re taking Xolair, tell your doctor. They may need to adjust your dose to ensure you receive the right amount for your weight.
If you experience weight changes during Xolair treatment, your doctor can help identify the cause. They can also recommend ways to maintain a weight that’s healthy for you.
* For details about Xolair’s dosages, see this article.
What side effects should I expect with Xolair injections for hives?
The side effects of Xolair can vary depending on which condition the drug is being used to treat. In clinical trials, the following side effects were common in people taking Xolair for hives:
- nausea
- nasopharyngitis (the common cold)
- sinus and respiratory infections
- pain in your joints
- headache
Other side effects may also occur. If you have concerns about your risk of side effects while taking Xolair for hives, talk with your doctor. They may recommend ways to help prevent or manage side effects.
Does Xolair treatment cause withdrawal symptoms?
No. Stopping Xolair treatment is not known to cause withdrawal symptoms. Symptoms of withdrawal can occur when you stop taking certain medications that your body has become dependent on. When your body is dependent on a drug, you need to continue taking that drug to function as you typically would.
Keep in mind that the symptoms of your condition may return if you stop taking Xolair. Talk with your doctor if you’d like to stop Xolair treatment. In some cases, you may need to stop taking Xolair. Your doctor will recommend the best time to do so and explain what to expect when treatment ends.
Is depression a side effect of Xolair?
Depression was not reported as a side effect in clinical trials of Xolair. However, some of Xolair’s side effects, such as fatigue and pain, may cause a depressive mood.
In many cases, nasal polyps, asthma, and hives are chronic (long-term) conditions. Due to the ongoing nature of these conditions and their symptoms, they may cause feelings of depression or low mood.
Talk with your doctor if you’re feeling depressed. They can help determine whether your condition or treatment side effects are causing your depressive mood. If you need additional support, they can also recommend healthcare professionals who specialize in treating depression.
Learn more about some of the side effects that Xolair may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Xolair.
Allergic reaction, which may be severe
Xolair can cause a mild allergic reaction or a severe allergic reaction called anaphylaxis. The drug has a
Anaphylaxis is a life threatening reaction. It can occur right after your dose or days after your dose. It can also occur on your first dose of Xolair or after you’ve been taking Xolair for a while. However, this was rarely seen in clinical trials.
Symptoms of a mild allergic reaction can include:
Symptoms of a severe allergic reaction can include the same symptoms as above, and:
- swelling under your skin, typically in your eyelids, lips, hands, or feet
- swelling of your mouth, tongue, or throat, which can make it hard to breathe
- trouble breathing
- low blood pressure
- shock (a life threatening reaction that causes reduced blood circulation to the organs)
- loss of consciousness
What you can do
Before your doctor prescribes Xolair, they’ll discuss the risk of severe allergic reaction. Be sure to tell them if you have any allergies to food or medications.
If your doctor determines Xolair is safe for you, they’ll give your dose of Xolair at their office or a clinic. This will allow them to monitor you for an allergic reaction following your dose. If you have a reaction, they can treat it at that time.
If after you leave your doctor’s office you have mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking Xolair. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.
If your doctor determines that it’s unlikely you’ll have a reaction to Xolair, they may recommend you self-inject Xolair doses at home. However, if you experience an allergic reaction at home, be sure to call your doctor or seek emergency help if needed.
Hair loss
Hair loss may occur with Xolair treatment. This side effect was rarely reported by people taking Xolair for hives. Hair loss wasn’t seen in people taking Xolair for asthma or nasal polyps.
What you can do
If you’re concerned about hair loss, talk with your doctor before starting Xolair treatment. They can discuss your risk of this side effect and recommend alternative treatments if needed.
Cancer
Some people taking Xolair have developed cancer during treatment with Xolair. This side effect was very rare in clinical trials of Xolair.
In trials, some adults and children ages 12 years and older developed breast cancer, prostate cancer, or skin cancer. However, more research is needed to determine whether the cancer was caused by Xolair. New cancer development was not reported in children ages 6 to 12 years old who were taking Xolair.
Symptoms can include:
- lump in your breast
- trouble urinating
- skin changes, such as a mole that changes in appearance
- fatigue
What you can do
Talk with your doctor about your personal and family history of cancer. They’ll discuss your risk of cancer before starting Xolair treatment. If you and your doctor decide that Xolair is safe for you, your doctor can advise you on specific cancer symptoms to watch for.
Headache
Headache may occur while taking Xolair. Headache was one of the common, mild side effects reported in Xolair clinical trials. This side effect was reported in people taking Xolair for nasal polyps, hives, and asthma.
What you can do
Talk with your doctor if you experience headaches during Xolair treatment. They may recommend over-the-counter medications to provide relief.
This drug comes with several warnings.
Boxed warning: Severe allergic reaction
This drug has a
Other precautions
Be sure to talk with your doctor about your health history before you take Xolair. This drug may not be the right treatment option for you if you have certain medical conditions or other factors that affect your health. These are known as drug-condition or drug-factor interactions. The conditions and factors to consider include:
Sudden asthma symptoms. Xolair should not be used to treat sudden symptoms of asthma or asthma attacks (flare-ups). The drug hasn’t been shown to be effective in treating urgent asthma problems. Tell your doctor if you are having sudden asthma symptoms or flare-ups. They’ll recommend the right drug to take to provide fast relief.
Steroid treatment. Tell your doctor if you’re taking steroid drugs for nasal polyps or asthma. Before starting Xolair treatment, your doctor will likely recommend you slowly stop taking steroids instead of suddenly stopping them. Your doctor will advise the best way for you to end the steroid treatment.
Parasitic infection. Xolair may increase the risk of parasitic worm infections in people who have an increased risk of these infections. Let your doctor know if you’ve had a parasitic infection or have been to places where they occur. They can test your stool to determine whether you have a parasitic infection and recommend treatment for it, if needed. Talk with your doctor about your risk of these infections before you start Xolair treatment.
Cancer. Taking Xolair may increase the risk of developing cancer or worsening current cancer. Some people taking Xolair have developed breast, prostate, or skin cancers. Talk with your doctor about your risk of cancer and any family history of cancer.
Allergies to latex. If you have a latex allergy, you should not use the prefilled syringes of Xolair. The prefilled syringes have a cap that contains latex. Tell your doctor if you have a latex allergy before starting Xolair. They may recommend you use the powdered form of the drug that comes in latex-free glass vials.
Pregnancy. It’s unknown whether Xolair is safe to take during pregnancy. See “Pregnancy and breastfeeding while taking Xolair” below for more details.
Breastfeeding. It’s not known whether Xolair is safe to take while you’re breastfeeding. For more information, view “Pregnancy and breastfeeding while taking Xolair” below.
Severe allergic reaction. If you’ve had a severe allergic reaction to Xolair or any of its ingredients, your doctor will likely not prescribe Xolair. If you’re not sure whether you’ve had a severe allergic reaction to this medication in the past, talk with your doctor before starting treatment.
Alcohol with Xolair
There aren’t any known interactions between alcohol and Xolair. However, you should discuss with your doctor whether drinking alcohol during Xolair treatment is safe for you.
Alcohol can affect your body in many ways that may affect your health. For example, alcohol can weaken your immune system. This can lead to an increased risk of cancer or infection. Alcohol can also cause dizziness, which is a side effect of Xolair. Drinking alcohol while taking Xolair may increase the risk or severity of this side effect.
Talk with your doctor about whether it’s safe for you to drink alcohol while taking Xolair.
Pregnancy and breastfeeding while taking Xolair
Below is information about taking Xolair during pregnancy or while breastfeeding.
Pregnancy
It’s not known whether Xolair is safe to take during pregnancy. This drug crosses through the placenta during pregnancy. (The placenta is the organ that passes nutrients to a developing fetus.) So the developing fetus is likely to be exposed to Xolair if the drug is taken during pregnancy.
Researchers studied Xolair’s safety during pregnancy in a study involving 250 pregnant females* with asthma. Most of the people in this group took Xolair during the first trimester (first 3 months) and at least half took Xolair for nearly 9 months.
The study reported no increase in pregnancy loss or congenital anomalies (also known as birth defects). This was in comparison with a group of pregnant females with asthma who did not take Xolair during pregnancy.
However, more infants were born with low birth weight to females who took Xolair compared with those who did not. This may be due to the females in the Xolair group having more severe asthma. Asthma that’s not managed can lead to pregnancy-related problems, such as low birth weight or premature birth. More studies are needed to know for sure.
If you are pregnant or are planning a pregnancy, talk with your doctor about whether it is safe to start or continue taking Xolair.
Breastfeeding
It’s not known whether Xolair passes into breast milk or whether it affects the ability to produce breast milk.
A study that assessed Xolair’s safety during pregnancy also monitored the child’s health after birth. Most of these children were breastfed by people who were taking Xolair. The study found no difference in the frequency of harmful outcomes or side effects in these children. This was compared with children who were breastfed by people not taking Xolair.
Talk with your doctor to learn the risks and benefits of breastfeeding while you’re taking Xolair.
* Sex and gender exist on spectrums. Use of the term “female” in this article refers to sex assigned at birth.
The most common side effects of Xolair are mild. However, the drug can cause serious side effects in rare cases. Talk with your doctor if you have side effects that are bothersome or serious. For more information, see “Side effect specifics” above.
If you’d like to learn more about Xolair, talk with your doctor or pharmacist. They can help answer any questions you have about side effects of taking the drug.
Besides talking with your doctor, you can do some research on your own. These articles might help:
- More information about Xolair. For details about other aspects of Xolair, refer to this article.
- Drug comparison. Learn how Xolair compares with Dupixent and Nucala.
- Cost. For information about Xolair and cost, view this article.
- A look at your condition. For details about your condition, see our:
- list of ear, nose, and throat articles
Disclaimer: Medical News Today 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.