Nucala (mepolizumab)

What is Nucala and how does it work?

Nucala is a prescription medicine used with other medicines:

  • for add-on maintenance treatment of asthma in people 12 years of age and older whose asthma is not controlled with their current asthma medicines. Nucala helps prevent severe asthma attacks (exacerbations).
  • for the treatment of adults with eosinophilic granulomatosis with polyangiitis (EGPA). Nucala helps reduce symptoms and flares, and it may allow your healthcare provider to reduce your oral corticosteroid medicine.
  • for the treatment of people 12 years of age and older with hypereosinophilic syndrome (HES). Nucala helps reduce symptoms and prevent flares.

  • Medicines such as Nucala reduce blood eosinophils. Eosinophils are a type of white blood cells that may contribute to your disease.
  • Nucala is not used to treat sudden breathing problems that occur with asthma.

It is not known if Nucala is safe and effective in children with severe asthma under 12 years of age.

It is not known if Nucala is safe and effective in children and adolescents with EGPA under 18 years of age.

Do not use Nucala if you are allergic to mepolizumab or any of the ingredients in Nucala.

What are the side effects of Nucala?

  • Allergic (hypersensitivity) reactions, including anaphylaxis. Serious allergic reactions can happen after you get your Nucala injection. Allergic reactions can sometimes happen hours or days after you get a dose of Nucala. Tell your healthcare provider or get emergency help right away if you have any of the following symptoms of an allergic reaction:
    • swelling of your face, mouth, and tongue
    • breathing problems
    • fainting, dizziness, feeling lightheaded (low blood pressure)
    • rash
    • hives
  • Herpes zoster infections. Herpes zoster infections that can cause shingles have happened in people who received Nucala.

The most common side effects of Nucala include: headache, injection site reactions (pain, redness, swelling, itching, or a burning feeling at the injection site), back pain, and weakness (fatigue).

These are not all the possible side effects of Nucala.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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What is the dosage for Nucala?

Your healthcare provider will prescribe the dose that is right for you depending on what you are being treated for.

When injection is given by a healthcare provider:

  • A healthcare provider will inject Nucala under your skin (subcutaneously) every 4 weeks.

When injection is given by a patient or patient caregiver with a prefilled syringe or prefilled autoinjector:

  • Use Nucala every 4 weeks exactly as your healthcare provider tells you to.
  • Read the Instructions for Use that comes with Nucala for instructions about the right way to give your injections at home.
  • Nucala may be prescribed as a single-dose prefilled autoinjector or as a single-dose prefilled syringe.
  • Before you use Nucala, your healthcare provider will show you or your caregiver how to give the injections.
  • You should inject Nucala under your skin (subcutaneously) into your thigh or stomach (abdomen). Also, a caregiver may give the injection in your upper arm.
  • If you miss a dose, inject a dose as soon as possible. Then continue (resume) your injection on your regular dosing schedule. If you do not notice that you have missed a dose until it is time for your next scheduled dose, then inject the next scheduled dose as planned. If you are not sure when to inject Nucala, call your healthcare provider.

What Drugs Interact with Nucala?

Formal drug interaction trials have not been performed with Nucala.

Notify your doctor if you are taking oral or inhaled corticosteroid medicines. Do not stop taking your corticosteroid medicines unless instructed by your healthcare provider. This may cause other symptoms that were controlled by the corticosteroid medicine to come back.

Is Nucala safe to take while pregnant or breastfeeding?

Before receiving Nucala, tell your healthcare provider about all of your medical conditions, including if you:

  • Are pregnant or plan to become pregnant. It is not known if Nucala may harm your unborn baby.
    • Pregnancy Registry. There is a pregnancy registry for women with asthma who receive Nucala while pregnant. The purpose of the registry is to collect information about the health of you and your baby. You can talk to your healthcare provider about how to take part in this registry or you can get more information and register by calling 1-877-311-8972 or go to
  • Are breastfeeding or plan to breastfeed. You and your healthcare provider should decide if you will use Nucala and breastfeed. You should not do both without talking with your healthcare provider first.


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Nucala (mepolizumab) helps prevent severe asthma attacks. It also helps reduce flares of eosinophilic granulomatosis with polyangitis (EGPA).

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You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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