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Mepolizumab Injection

pronounced as (me" poe liz' ue mab)

Why is this medication prescribed?

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). Mepolizumab injection is also used along with other medications to treat chronic rhinosinusitis with nasal polyps (ongoing runny nose, sinus swelling or nasal congestion, with or without a reduced sense of smell or pain and pressure in the face) in adults whose symptoms are not controlled with other medications. 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 also used to treat hypereosinophilic syndrome (HES; group of blood disorders that occurs with high levels of certain white blood cells) in adults and children 12 years and older who have had this condition for 6 months or longer. 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.

How should this medicine be used?

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 solution 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.

Other uses for this medicine

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What special precautions should I follow?

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 or have ever had shingles (a painful rash that occurs after infection with herpes zoster or chickenpox) or 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 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 shingles. You may need to get vaccinated to protect you from this infection.

What special dietary instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget a dose?

Use the missed dose as soon as you remember it and then continue your regular dosing schedule. Do not use a double dose to make up for a missed one. Call your doctor if you miss a dose and have questions about what to do.

What side effects can this medication cause?

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
  • mouth or throat pain
  • joint pain
  • nasal dryness

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

  • wheezing or difficulty breathing
  • shortness of breath
  • cough
  • chest tightness
  • flushing
  • hives
  • rash
  • swelling of the face, mouth, and tongue
  • difficulty swallowing
  • fainting or dizziness

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

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( or by phone (1-800-332-1088).

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store mepolizumab injection in the refrigerator or in an unopened carton at room temperature for up to 7 days, but do not freeze it. Once removed from the carton, mepolizumab injection can be stored at room temperature for up to 8 hours.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach.

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website ( for more information if you do not have access to a take-back program.

In case of emergency/overdose

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

What other information should I know?

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.

Brand names

  • Nucala®
Last Revised - 10/15/2021