Mepolizumab Injection


Mepolizumab injection is used along with other medications to prevent wheezing, difficulty breathing, chest tightness, and coughing caused by asthma in certain children 6 years of age and older and adults whose asthma is not controlled with their current asthma medication(s). It is also used to treat eosinophilic granulomatosis with polyangiitis (EGPA; a condition that involves asthma, high levels of white blood cells, and blood vessel swelling) in adults. Mepolizumab injection is in a class of medications called monoclonal antibodies. It works by blocking the action of a certain natural substance in the body that causes the symptoms of asthma.

Side Effects Of Mepolizumab Injection

Mepolizumab injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • pain, redness, swelling, warmth, burning, or itching in the place mepolizumab was injected
  • headache
  • dry and itchy skin with or without red, scaly rashes
  • back pain
  • muscle spasms

Some side effects can be serious. If you experience any of these symptoms or those listed in the WARNINGS and PRECAUTIONS section, call your doctor immediately or get emergency medical treatment:

Mepolizumab injection may cause other side effects. Call your doctor if you have any unusual problems while receiving this medication.

Warnings & Precautions

Before receiving mepolizumab injection:

  • tell your doctor and pharmacist if you are allergic to mepolizumab injection, any medications, or any of the ingredients in mepolizumab injection. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: oral corticosteroids such as prednisone (Rayos) or an inhaled corticosteroid. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have not had chickenpox (varicella) or you have or have ever had any type of infection caused by worms.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while receiving mepolizumab injection, call your doctor.
  • if you have any other medical conditions, such as arthritis, or eczema (a skin disease), they may worsen when your oral steroid dose is decreased. Tell your doctor if this happens or if you experience any of the following symptoms during this time: extreme tiredness, muscle weakness, or pain; sudden pain in stomach, lower body, or legs; loss of appetite; weight loss; upset stomach; vomiting; diarrhea; dizziness; fainting; depression; irritability; and darkening of the skin. Your body may be less able to cope with stress such as surgery, illness, severe asthma attack, or injury during this time. Call your doctor right away if you get sick and be sure that all healthcare providers who treat you know that you recently decreased your oral steroid dose.
  • tell your doctor if you have not been vaccinated against chickenpox. You may need to get a vaccine (shot) to protect you from this infection.

Dosage Of Mepolizumab Injection

Mepolizumab injection comes as a prefilled syringe, a prefilled autoinjector, or as a powder to be mixed with water and injected subcutaneously (just under the skin). It is usually given once every 4 weeks. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Use mepolizumab injection exactly as directed. Do not inject more or less of it or inject it more often than prescribed by your doctor. Your doctor will determine the length of your treatment based on your condition and how well you respond to the medication.

You may receive your first dose of mepolizumab injection in your doctor’s office. After that, your doctor may allow you or a caregiver to give the injections at home. Before you use mepolizumab injection yourself the first time, read the manufacturer’s information for the patient that comes with the medication. Ask your doctor or pharmacist to show you or the person who will be giving the medication how to inject it.

Use each syringe or autoinjector only once and inject all of the solutions in the syringe or autoinjector. Dispose of used syringes or autoinjectors in a puncture-resistant container. Talk to your doctor or pharmacist about how to dispose of the puncture-resistant container.

Remove the prefilled syringe or autoinjector from the refrigerator. Place it on a flat surface without removing the needle cap and allow it to warm to room temperature for 30 minutes (no longer than 8 hours) before you are ready to inject the medication. Do not try to warm the medication by heating it in a microwave, placing it in hot water, leaving it in sunlight, or through any other method.

Do not shake a syringe that contains mepolizumab.

If you are using mepolizumab and have asthma, continue to take or use all other medications that your doctor has prescribed to treat your asthma. Do not decrease your dose of any other asthma medication or stop taking any other medication that has been prescribed by your doctor unless your doctor tells you to do so. Your doctor may want to decrease the doses of your other medications gradually.

Always look at mepolizumab solution before injecting it. Check that the expiration date has not passed and that the liquid is clear and colorless or slightly yellow to slightly brown. The liquid should not contain visible particles. Do not use a syringe that is frozen or if the liquid is cloudy or contains small particles.

You can inject mepolizumab injection anywhere on the front of your thighs (upper leg) or abdomen (stomach) except your navel and the area 2 inches (5 centimeters) around it. If a caregiver injects the medication, the back of the upper arm may also be used. To reduce the chances of soreness or redness, use a different site for each injection. Do not inject into an area where the skin is tender, bruised, red, or hard or where you have scars or stretch marks.

Mepolizumab injection is not used to treat a sudden attack of asthma symptoms. Your doctor will prescribe a short-acting inhaler to use during attacks. Talk to your doctor about how to treat symptoms of a sudden asthma attack. If your asthma symptoms get worse or if you have asthma attacks more often, be sure to talk to your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.


Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body’s response to mepolizumab injection.

Ask your pharmacist any questions you have about mepolizumab injection.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.