Fasenra is a brand-name prescription medication. It’s approved to treat severe eosinophilic asthma in adults as well as children ages 12 years and older. Asthma is a condition in which your airways become swollen, making it hard to breathe. With eosinophilic asthma, you also have high levels of eosinophils (a type of white blood cell).

You’ll use Fasenra with your other asthma medications rather than by itself. Keep in mind that Fasenra isn’t a rescue inhaler. So you shouldn’t use it to treat asthma flare-ups or a severe kind of asthma called status asthmaticus. Fasenra also shouldn’t be used to treat other eosinophilic conditions.

Fasenra contains the active drug benralizumab, which is a biologic medication. Biologics are made from living cells rather than from chemicals. Fasenra is also called a monoclonal antibody. This type of drug is a large protein that affects the way certain parts of your body work.

New form available

Fasenra comes in two forms. In 2017, the Food and Drug Administration (FDA) approved Fasenra as a prefilled syringe. A healthcare provider gives you this form of the drug as an injection under your skin (subcutaneous injection).

But in October 2019, the FDA approved a new form of Fasenra. This new form is a prefilled autoinjector pen that’s self-injectable. This means that instead of having to go to your doctor’s office for injections, you can give yourself injections at home after you receive training.

Each syringe or pen contains one dose of Fasenra. Both forms of the drug have one strength: 30 mg/mL.

Effectiveness

A clinical study looked at 1,204 people who had severe eosinophilic asthma and were using at least two medications to treat asthma. They were then given Fasenra or a placebo (treatment with no active drug). After 48 weeks, 35% of people who took Fasenra had asthma flare-ups, compared with 51% of people who took a placebo.

For more information on the effectiveness of Fasenra, see the “Fasenra uses” section below.

Fasenra is available only as a brand-name medication. It contains the active drug benralizumab. This means benralizumab is the ingredient that makes Fasenra work.

Fasenra isn’t currently available in biosimilar form.

A biosimilar is a drug that’s similar to a brand-name medication. A generic drug, on the other hand, is an exact copy of a brand-name medication. Biosimilars are based on biologic medications, which are made from living sources such as proteins or DNA. Generics are based on regular medications, which are made from chemicals. Biosimilars and generics also usually cost less than brand-name drugs.

Fasenra can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Fasenra. These lists don’t include all possible side effects.

For more information on the possible side effects of Fasenra, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may be bothersome.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs they have approved. If you would like to report to the FDA a side effect you’ve had with Fasenra, you can do so through MedWatch.

More common side effects

The more common side effects of Fasenra can include:

If you have a headache or sore throat after taking Fasenra, the side effects will likely fade. But you should tell your doctor if these side effects become more severe or don’t go away. If needed, your doctor can recommend treatments to help you feel better.

Serious side effects

Serious side effects from Fasenra aren’t common, but they can occur. Allergic reaction, which is discussed in detail below, was the only serious side effect reported during clinical studies.

Side effect details

You may wonder how often certain side effects occur with this drug, or whether certain side effects pertain to it. Here’s some detail on several of the side effects this drug may or may not cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Fasenra. But allergic reactions to Fasenra are rare. In clinical studies, only 3% of people who took Fasenra had an allergic reactions. In comparison, 3% of people who took a placebo (treatment with no active drug) had an allergic reaction.

Symptoms of an allergic reaction to Fasenra can include:

  • swelling of your face, including your mouth and tongue
  • trouble breathing
  • fainting
  • dizziness
  • low blood pressure or feeling lightheaded
  • rash
  • hives (itchy welts on your skin)

Call your doctor right away if you have a severe allergic reaction to Fasenra. Call 911 if your symptoms feel life threatening or if you think you’re having a medical emergency.

Headache

Headaches may occur with Fasenra use. In clinical studies, 8% of people who took Fasenra had headaches. In comparison, 6% of people who took a placebo had headaches.

Although headaches can be common while using Fasenra, they’re usually not serious. If you have a headache during your treatment, it’ll likely go away after a few hours. But if a headache doesn’t go away, let your doctor know. They may recommend treatments to help you feel better.

Fever

A fever may occur after Fasenra use, but this side effect isn’t very common. In clinical studies, only 3% of people who took Fasenra had a fever. In comparison, 2% of people who took a placebo had a fever. The fevers weren’t serious and didn’t cause any problems with people’s asthma treatment.

If you have a fever after taking Fasenra, you can try to make yourself more comfortable by taking a cool bath.

But if your fever lasts more than 3 days or is higher than 103°F (about 39.4°C), tell your doctor. They may recommend treatments to help reduce your fever and check to see what may be causing it.

Sore throat

Pain, scratchiness, or irritation in the throat may occur with Fasenra. In clinical studies, sore throat occurred in 5% of people taking Fasenra compared with 3% of people who took a placebo.

If you have a sore throat while using Fasenra, it’ll probably improve on its own within a few days.

But if your throat pain is severe or lasts more than a few days, tell your doctor. They may look at your throat and recommend treatments to help you feel better.

Side effects in children

In clinical studies, Fasenra was found to be safe for use in children ages 12 years and older. The side effects seen in children were very similar to those seen in adults. See the “Side effect details” section above to learn more.

Fasenra is prescribed using a standard dosage. This means that most people taking the drug will be prescribed the same dosage. Dosage means the amount of drug you take for each dose and how often you take a dose.

Be sure to take the dosage your doctor prescribes for you. They will determine the best dosage to fit your needs.

Drug forms and strengths

Fasenra comes in two forms:

  • A prefilled syringe. A healthcare provider will give you the drug as an injection under your skin (subcutaneous injection).
  • A prefilled autoinjector pen. You can use the pen to give yourself injections after you receive training from your doctor or pharmacist.

Each syringe or pen contains one dose of Fasenra. Both forms of the drug have one strength: 30 mg/mL.

Dosage for asthma

During the first 3 months of treatment, you’ll have one injection (30 mg/mL) once every 4 weeks. After that, you’ll have one injection once every 8 weeks.

Pediatric dosage

The dosage of Fasenra for children ages 12 years and older is the same as for adults. (See the “Dosage for asthma” section right above.)

Fasenra isn’t approved for use in children younger than age 12 years.

What if I miss a dose?

If you miss a dose of Fasenra, call your doctor right away. They’ll help you decide when you should have your next dose.

To avoid missing a dose of Fasenra, try setting a reminder on your phone or calendar.

Will I need to use this drug long term?

Fasenra is meant to be used as a long-term treatment. If you and your doctor determine that Fasenra is safe and effective for you, you’ll likely take it long term.

Other drugs are available that can treat severe eosinophilic asthma. With this condition, high levels of eosinophils (a type of white blood cell) are found in your airways. These cells cause inflammation (swelling) and trigger asthma flare-ups.

Some drugs may be better suited for you than others. If you’re interested in finding an alternative to Fasenra, talk with your doctor. They can tell you about other medications that may work well for you.

Examples of drugs that may be used to treat severe eosinophilic asthma include:

You may wonder how Fasenra compares to other medications that are prescribed for similar uses. Here we look at how Fasenra and Nucala are alike and different.

About

Fasenra contains the active drug benralizumab, while Nucala contains the active drug mepolizumab.

Both Fasenra and Nucala are called biologic drugs because they’re made from living cells rather than from chemicals. Both drugs are also known as monoclonal antibodies. These types of drugs are large proteins that affect the way certain parts of your body work.

Fasenra and Nucala both belong to the same class of drugs called anti-interleukin 5 monoclonal antibodies. (A drug class is a group of medications that work in a similar way in your body.)

Uses

The Food and Drug Administration (FDA) has approved Fasenra and Nucala to treat severe eosinophilic asthma in adults as well as children. Fasenra may be used in children ages 12 years and older. Nucala, on the other hand, may be used in children ages 6 years and older.

Asthma is a condition in which your airways become swollen, making it hard to breathe. With eosinophilic asthma, you also have high levels of eosinophils (a type of white blood cell).

Both Fasenra and Nucala should be used in addition to your other asthma medications rather than by themselves. Neither drug is a rescue inhaler. So you shouldn’t them to treat asthma flare-ups or a severe kind of asthma called status asthmaticus.

Fasenra also shouldn’t be used to treat other eosinophilic conditions.

Nucala, on the other hand, is also approved to treat a condition called eosinophilic granulomatosis with polyangiitis (EPGA) in adults.

Drug forms and administration

Fasenra comes in two forms:

  • A prefilled syringe. A healthcare provider will give you the drug as an injection under your skin (subcutaneous injection).
  • A prefilled autoinjector pen. You can use the pen to give yourself injections after you receive training from a healthcare provider.

Each syringe or pen contains one dose of Fasenra.

Nucala comes in these three forms:

  • A vial of powder. A healthcare provider will mix the powder with sterile water to form a solution. Then they’ll give you the medication as a subcutaneous injection.
  • A prefilled autoinjector pen. Once a healthcare provider teaches you how to use the pen, you’ll be able to give yourself injections under your skin.
  • A prefilled syringe. As with the pen form, once you learn how to use the syringe, you can give yourself injections under your skin.

Each vial, autoinjector pen, or syringe contains one dose of Nucala.

Side effects and risks

Fasenra and Nucala belong to the same class of drugs. Therefore, both medications can cause some similar side effects. But they can also cause some different side effects. Below are examples of these side effects.

More common side effects

These lists contain examples of more common side effects that can occur with Fasenra, with Nucala, or with both drugs (when taken individually).

  • Can occur with Fasenra:
  • Can occur with Nucala:
    • reactions at the site of your injection (redness, swelling, pain, or burning in the injection area)
    • fatigue (lack of energy)
    • back pain
  • Can occur with both Fasenra and Nucala:

Serious side effects

These lists contain examples of serious side effects that can occur with Fasenra, with Nucala, or with both drugs (when taken individually).

  • Can occur with Fasenra:
    • no unique serious side effects
  • Can occur with Nucala:
  • Can occur with both Fasenra and Nucala:

Effectiveness

Fasenra and Nucala have different FDA-approved uses, but they’re both used to treat severe eosinophilic asthma.

Separate studies of the two drugs were compared in a larger review of studies. People who took either Fasenra or Nucala had fewer flare-ups than people who took a placebo (treatment with no active drug).

Costs

Fasenra and Nucala are both brand-name drugs. There are currently no biosimilar forms of either drug available.

A biosimilar is a drug that’s similar to a brand-name medication. A generic drug, on the other hand, is an exact copy of a brand-name medication. Biosimilars are based on biologic medications, which are made from living sources such as proteins or DNA. Generics are based on regular medications, which are made from chemicals. Biosimilars and generics also usually cost less than brand-name drugs.

Both biosimilars and generics are considered to be just as safe and effective as their parent drugs. However, brand-name medications usually cost more than biosimilars or generics.

According to estimates on WellRx.com, Fasenra syringes and autoinjector pens cost significantly more than Nucala syringes and autoinjector pens. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

Like Nucala (above), the drug Xolair has uses similar to those of Fasenra. Here’s a comparison of how Fasenra and Xolair are alike and different.

About

Fasenra contains the drug benralizumab, while Xolair contains the drug omalizumab.

Both Fasenra and Nucala are called biologic drugs because they’re made from living cells rather than from chemicals. Both drugs are also known as monoclonal antibodies. These types of drugs are large proteins that affect the way certain parts of your body work.

Fasenra belongs to a class of drugs called interleukin-5 monoclonal antibodies. Xolair belongs to a different class of drugs called immunoglobin-E monoclonal antibodies. (A drug class is a group of medications that work in a similar way in your body.)

Uses

Here’s some information about the uses of Fasenra and Xolair.

What Fasenra is used for

The Food and Drug Administration (FDA) approved Fasenra to treat severe eosinophilic asthma in adults as well as children ages 12 years and older. Asthma is a condition in which your airways become swollen, making it hard to breathe. With eosinophilic asthma, you also have high levels of eosinophils (a type of white blood cell).

You’ll use Fasenra with your other asthma medications rather than by itself. Keep in mind that Fasenra isn’t a rescue inhaler. So you shouldn’t use it to treat asthma flare-ups or a severe kind of asthma called status asthmaticus. Fasenra also shouldn’t be used to treat other eosinophilic conditions.

What Xolair is used for

Xolair is approved to treat allergic asthma that’s moderate to severe and persistent. The drug is for use in adults as well as children ages 6 years and older.

Xolair is also approved to treat chronic idiopathic urticaria (hives) in adults as well as children ages 12 years and older.

You’ll use Xolair with your other asthma medications rather than by itself. Keep in mind that Xolair isn’t a rescue inhaler. So you shouldn’t use it to treat asthma flare-ups or a severe kind of asthma called status asthmaticus. Xolair also shouldn’t be used to treat other eosinophilic conditions.

Drug forms and administration

Fasenra comes in two forms:

  • A prefilled syringe. A healthcare provider will give you the drug as an injection under your skin (subcutaneous injection).
  • A prefilled autoinjector pen. You can use the pen to give yourself injections after you receive training from a healthcare provider.

Each syringe or pen contains one dose of Fasenra.

Xolair also comes in these two forms:

  • A prefilled syringe. A healthcare provider will give you the drug as a subcutaneous injection.
  • A vial of powder. A healthcare provider will mix the powder with sterile water to form a solution. Then they’ll give you the medication as a subcutaneous injection.

Both the syringe and vial contain one dose of Xolair.

Side effects and risks

Fasenra and Xolair are both monoclonal antibodies, but they have different effects on your body. Therefore, both medications can cause some similar or some different side effects. Below are examples of these side effects.

More common side effects

These lists contain examples of more common side effects that can occur with Xolair, or with Fasenra and Xolair (when taken individually).

Serious side effects

These lists contain examples of serious side effects that can occur with Xolair, or with Fasenra and Xolair (when taken individually).

  • Can occur with Fasenra:
    • no unique serious side effects
  • Can occur with Xolair:
    • cancer, such as breast, skin, or prostate cancer
    • inflammation in your blood vessels
    • fever, joint pain, and rash that happen 1 to 5 days after getting a dose of Xolair
    • infections caused by parasites
    • heart problems, such as a heart attack or chest pain
    • problems with your blood circulation, such as blood clots in your lungs or legs
  • Can occur with both Fasenra and Xolair

* Xolair has a boxed warning for a severe allergic reaction called anaphylaxis. This is the most serious warning from the Food and Drug Administration (FDA).

Effectiveness

Fasenra and Xolair have different FDA-approved uses, but they’re both used to treat asthma.

These drugs haven’t been directly compared in clinical studies. While some studies have found Fasenra to be effective for treating severe eosinophilic asthma, other studies have found Xolair to be effective for treating asthma.

Costs

Fasenra and Xolair are both brand-name drugs. There are currently no biosimilar forms of either drug available.

A biosimilar is a drug that’s similar to a brand-name medication. A generic drug, on the other hand, is an exact copy of a brand-name medication. Biosimilars are based on biologic medications, which are made from living sources such as proteins or DNA. Generics are based on regular medications, which are made from chemicals. Biosimilars and generics also usually cost less than brand-name drugs.

Both biosimilars and generics are considered to be just as safe and effective as their parent drugs. However, brand-name medications usually cost more than biosimilars or generics.

According to estimates on WellRx.com, Fasenra syringes cost significantly more than Xolair syringes. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

The Food and Drug Administration (FDA) approves prescription drugs such as Fasenra to treat certain conditions. Fasenra may also be used off-label for other conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Fasenra for asthma

Fasenra is FDA-approved to treat severe eosinophilic asthma in adults as well as children ages 12 years and older.

You’ll use Fasenra with your other asthma medications rather than by itself. Keep in mind that Fasenra isn’t a rescue inhaler. So you shouldn’t use it to treat asthma flare-ups or a severe kind of asthma called status asthmaticus. Fasenra also shouldn’t be used to treat other eosinophilic conditions.

What is severe eosinophilic asthma?

Asthma is a condition that affects your airways, making them swollen. As a result, air can’t move properly into and out of your lungs. Asthma is called severe when you keep having symptoms despite using multiple asthma treatments.

With severe eosinophilic asthma, you have high levels of eosinophils in your body. These are a type of white blood cell that are found mostly in your airways. High levels of eosinophils can cause swelling in your airways and lead to severe eosinophilic asthma.

Effectiveness

Two clinical studies looked at 2,510 people with severe eosinophilic asthma. Half of the people in these studies took Fasenra and half took a placebo (treatment with no active drug). All the people in the studies were also taking at least two other medications to treat their asthma.

In the first study, 35% of people who took Fasenra had asthma flare-ups, compared with 51% of people who took a placebo. In the second study, 40% of people who took Fasenra had asthma flare-ups, compared with 51% of people who took a placebo.

Fasenra for other conditions

In addition to the use listed above, Fasenra may be used off-label for other conditions. Off-label drug use is when a drug that’s approved for one condition is used for a different one that’s not approved.

Fasenra for nasal polyps (off-label use)

Nasal polyps are growths in the lining of your nose that aren’t cancerous. Fasenra isn’t currently approved to treat nasal polyps, but clinical trials such as this one are looking at whether the drug is effective for this condition. A review of studies supports using medications that are in the same class as Fasenra to treat nasal polyps. (A drug class is a group of medications that work in a similar way in your body.)

If you have nasal polyps and you’re interested in taking Fasenra, talk with your doctor. They’ll recommend whether the drug is a good option for you.

Fasenra for COPD (not an appropriate use)

Fasenra isn’t approved for use in people with chronic obstructive pulmonary disease (COPD). Two clinical studies found that Fasenra was not effective at preventing flare-ups in people with moderate to very severe COPD. Ask your doctor what other COPD treatment options are right for you.

Fasenra for children

Fasenra is approved to treat severe eosinophilic asthma in children ages 12 years and older.

Fasenra hasn’t been studied in children younger than 12 years of age.

Fasenra is meant to be used with the other medications you’re taking for asthma treatment. Fasenra isn’t meant to replace any of your drugs, including corticosteroids.

Fasenra also isn’t meant to replace your rescue inhaler, which is used to treat sudden asthma symptoms. You’ll need to keep using your rescue inhaler and other asthma medications as directed by your doctor.

Drugs often used to treat asthma that may be used with Fasenra include:

  • inhaled and oral corticosteroids, such as:
    • beclomethasone (Qvar, Beclovent)
    • budesonide (Pulmicort)
    • ciclesonide (Alvesco)
    • fluticasone (ArmonAir, Arnuity, Flovent)
    • mometasone (Asmanex)
    • triamcinolone
  • beta-adrenergic bronchodilators, such as:
    • albuterol (Proventil HFA, Ventolin HFA)
    • terbutaline (Brethine)
  • leukotriene pathway modifiers, such as:
  • muscarinic antagonists such as:
  • theophylline

Talk with your doctor or pharmacist about which medications you’ll need to take with Fasenra. They can help make sure that you feel comfortable taking the drugs.

Here are answers to some frequently asked questions about Fasenra.

Is Fasenra a biologic?

Yes. Fasenra is a biologic drug, which is created from living cells. In comparison, regular drugs are made from chemicals.

Fasenra is also a monoclonal antibody. This is a type of drug that attaches to proteins in your immune system (your body’s defense against infection). By doing this, Fasenra blocks some of the actions of the proteins that cause symptoms of asthma.

Should I use Fasenra to treat asthma attacks?

No, you shouldn’t. Fasenra isn’t meant to treat sudden asthma symptoms, which are called asthma attacks or flare-ups. Instead, Fasenra is used as a long-term asthma treatment. The drug works in your body to help prevent asthma flare-ups in the first place.

If you do have an asthma attack, Fasenra won’t help treat your symptoms. You’ll probably need to use your rescue inhaler, as directed by your doctor. Check with your doctor on the best ways to treat asthma attacks and help prevent them.

Is Fasenra a steroid?

No. Fasenra isn’t a steroid. It’s a type of drug called a biologic. (For more about biologics, see “Is Fasenra a biologic?” above.) Steroids are medications that are made from a combination of chemicals.

Even though Fasenra and steroids are both used to treat asthma, these drugs work differently in your body. Fasenra targets and removes eosinophils from your body. Eosinophils (a type of white blood cell) are found in your airways. These cells cause inflammation (swelling) and trigger asthma flare-ups. Steroids reduce inflammation and decrease the amount of mucus in your airways. This makes it easier for you to breathe.

You’ll often take steroids every day for long-term treatment, or you may take them just during asthma flare-ups. But you won’t take Fasenra every day, and it isn’t effective during asthma flare-ups.

If you have questions about steroids or Fasenra, ask your doctor or pharmacist.

Will I still need to take steroids while taking Fasenra?

You might. Fasenra isn’t meant to replace any of your current asthma medications. You’ll use Fasenra with the other drugs you’re taking, which may include steroids.

Talk with your doctor or pharmacist to learn more about Fasenra and your other asthma medications.

There aren’t any known interactions between Fasenra and alcohol. But alcohol can be dangerous for people with asthma.

According to an article published in the International Archives of Allergy and Immunology, experts believe that drinking alcohol can trigger asthma flare-ups.

If you drink alcohol, talk with your doctor about how much is safe for you to consume during your Fasenra treatment.

There aren’t any known interactions between Fasenra and any drugs, herbs, foods, or supplements.

Before taking Fasenra, talk with your doctor or pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

As with all medications, the cost of Fasenra can vary. To find current prices for Fasenra in your area, check out WellRx.com. The cost you find on WellRx.com is what you may pay without insurance. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

It’s important to note that if you use the autoinjector pen form of Fasenra, you’ll have to get it at a specialty pharmacy. This type of pharmacy is authorized to carry specialty medications. These are drugs that may be expensive or may require help from healthcare professionals to be used safely and effectively.

Your insurance plan may require you to get prior authorization before approving coverage for Fasenra. This means that your doctor and insurance company will need to communicate about your prescription before the insurance company will cover the drug. The insurance company will review the request and let you and your doctor know if your plan will cover Fasenra.

If you’re not sure if you’ll need to get prior authorization for Fasenra, contact your insurance company.

Financial and insurance assistance

If you need financial support to pay for Fasenra, or if you need help understanding your insurance coverage, help is available.

AstraZeneca, the manufacturer of Fasenra, has reimbursement counselors on staff who can discuss cost savings options with you. For more information and to find out if you’re eligible for support, call 833-360-HELP (833-360-4357) or visit the program website.

Fasenra comes in two forms: a prefilled syringe and a prefilled autoinjector pen.

Prefilled syringe

With the prefilled syringe form, a healthcare provider will give you Fasenra as an injection under your skin (subcutaneous injection). You’ll go to your doctor’s office or a clinic for the injections.

Fasenra may be injected in different parts of your body such as your upper arms, thighs, or belly.

Before leaving the office or clinic, make sure that you have an appointment for your next Fasenra injection scheduled.

Prefilled autoinjector pen

With the prefilled autoinjector pen form, you’ll use the pen to give yourself injections after you receive training from a healthcare provider.

The Fasenra site also has some useful resources on using the autoinjector pen. These include an FAQ, a video, and how to contact a nurse for training help.

How often the drug is given

During the first 3 months of treatment, you’ll have one injection once every 4 weeks. After that, you’ll have one injection once every 8 weeks.

To avoid missing a dose, try setting a reminder on your phone or calendar.

Fasenra is FDA-approved to treat severe eosinophilic asthma in adults as well as children ages 12 years and older.

You’ll use Fasenra with your other asthma medications rather than by itself. Keep in mind that Fasenra isn’t a rescue inhaler. So you shouldn’t use it to treat asthma flare-ups or a severe kind of asthma called status asthmaticus. Fasenra also shouldn’t be used to treat other eosinophilic conditions.

What is severe eosinophilic asthma?

Asthma is a condition that affects your airways, which are a network of tubes that allow air to move from outside of your body into your lungs. Asthma is called severe when you keep having symptoms despite using multiple asthma treatments.

If you have asthma, your airways are swollen. As a result, air can’t move properly into and out of your lungs. Since oxygen is carried in air, this condition reduces how much oxygen reaches the cells inside your body. The most common symptoms of asthma include:

  • wheezing
  • coughing
  • chest pain
  • trouble breathing

With severe eosinophilic asthma, you have high levels of eosinophils in your body. These are a type of white blood cell that are found mostly in your airways. Normal levels of eosinophils help your body fight against infections. But higher levels can cause swelling in your airways and lead to severe eosinophilic asthma.

What does Fasenra do?

Eosinophils contain a protein called interleukin-5 receptor. Fasenra attaches to eosinophils by binding to this receptor. Once Fasenra is attached, it tells your immune system to destroy the eosinophils. This reduces the number of eosinophils in your airways. As a result, there’s less inflammation (swelling), and you have a lower risk for asthma flare-ups.

How long does it take to work?

Fasenra removes almost all eosinophils from your blood within 24 hours after taking the drug. But severe eosinophilic asthma typically requires treatment for some time before the condition improves.

Fasenra should reduce your risk for asthma flare-ups as long as you keep taking it. Don’t stop taking Fasenra if your asthma eases and you have fewer flare-ups, unless your doctor tells you to do so. Stopping treatment may reduce the effect of Fasenra and lead to asthma flare-ups.

It’s not known whether Fasenra is safe to take while pregnant. There haven’t been clinical studies in humans that show the effect of the drug during pregnancy. However, studies of similar medications suggest that if Fasenra is used during the third trimester of pregnancy (week 28 through the birth of your baby), the drug will pass to the growing baby.

In animal studies, Fasenra didn’t cause harm to babies whose mothers were given the drug. But animal studies don’t always predict what may occur in humans.

If you’re pregnant or are planning to become pregnant, talk with your doctor before taking Fasenra. They can let you know whether or not it’s safe for you to take Fasenra and recommend other treatment options, if needed.

Pregnancy study

If you’re pregnant and have already taken Fasenra during your pregnancy, you may be able to join the Fasenra & Pregnancy Study. Such studies help doctors learn more about the safety of certain drugs during pregnancy. To learn more, call 877-311-8972 or visit the study website.

It’s not known if Fasenra is safe to take during pregnancy. If you or your sexual partner can become pregnant, talk with your doctor about your birth control needs while you’re using Fasenra.

It’s not known for sure if Fasenra is safe to use while you’re breastfeeding. Studies of similar medications show that Fasenra may pass into human breast milk. However, it’s not known if the drug would have any effect on a breastfed child.

If you’re breastfeeding or plan to breastfeed, talk with your doctor before taking Fasenra. They can review the benefits and possible risks of breastfeeding while using this drug. Your doctor can also recommend the safest ways to feed your child.

Before taking Fasenra, talk with your doctor about your health history. Fasenra may not be right for you if you have certain medical conditions or other factors affecting your health. These include:

  • Allergic reaction. If you’ve ever had an allergic reaction to Fasenra or any of its ingredients, you shouldn’t take Fasenra. Ask your doctor if they can recommend a different medication for you to use.
  • Parasitic infections. Taking Fasenra may reduce your body’s ability to fight off parasitic infections. If you have a helminth infection (caused by a worm parasite), tell your doctor before taking Fasenra. They’ll prescribe medication to treat your infection before you start using Fasenra.
  • Pregnancy and breastfeeding. It’s not known if Fasenra is safe to use during pregnancy or while breastfeeding. For more information, please see the “Fasenra and pregnancy” and “Fasenra and breastfeeding” sections above.

Note: For more information about the potential negative effects of Fasenra, see the “Fasenra side effects” section above.

Do not use more Fasenra than your doctor recommends.

What to do in case of overdose

If you think you’ve taken too much of this drug, call your doctor. You can also call the American Association of Poison Control Centers at 800-222-1222 or use their online tool. But if your symptoms are severe, call 911 or go to the nearest emergency room right away.

When you get Fasenra from the pharmacy, the pharmacist will add an expiration date to the label on the bottle. This date is typically 1 year from the date they dispensed the medication.

The expiration date helps guarantee that the medication is effective during this time. The current stance of the Food and Drug Administration (FDA) is to avoid using expired medications. If you have unused medication that has gone past the expiration date, talk to your pharmacist about whether you might still be able to use it.

Storage

How long a medication remains good can depend on many factors, including how and where you store the medication.

You should store Fasenra autoinjector pens in a refrigerator between 36°F to 46°F (2°C to 8°C). If needed, you can keep the drug at room temperature for up to 14 days. But if you don’t use the Fasenra pens within that time frame, you must dispose of them.

Keep Fasenra inside its original package and protect the autoinjector pens from light. Don’t shake, freeze, or expose Fasenra to heat.

Disposal

If you no longer need to take Fasenra and have leftover medication, it’s important to dispose of it safely. This helps prevent others, including children and pets, from taking the drug by accident. It also helps keep the drug from harming the environment.

After using a Fasenra autoinjector pen, be sure to put it in your sharps disposal container.

The FDA website provides several useful tips on medication disposal. You can also ask your pharmacist for information on how to dispose of your medication.

The following information is provided for clinicians and other healthcare professionals.

Indications

Fasenra is indicated to treat severe eosinophilic asthma. It’s not indicated to treat any other eosinophilic disease, acute bronchospasms, or other asthmatic episodes.

Fasenra can be used in adults as well as children ages 12 years and older.

Mechanism of action

The exact mechanism of action of Fasenra has not been completely elucidated.

Fasenra is a humanized IgG1-kappa monoclonal antibody. Its target is the interleukin-5 receptor (IL-5 receptor), to which it binds via the alpha subunit of the receptor. The dissociation constant of this binding is 11 pM.

The IL-5 receptor regulates the growth, multiplication, and function of eosinophils and basophils. By targeting this receptor, Fasenra promotes destruction of these cells via antibody-dependent cell-mediated cytotoxicity. Within 24 hours, Fasenra results in the near-complete elimination of eosinophils in the bloodstream. This reduces inflammation and is thought to reduce asthma symptoms.

Pharmacokinetics and metabolism

Fasenra has a linear pharmacokinetic profile. When administered subcutaneously to patients with asthma, Fasenra has a bioavailability of 59%. Once administered, Fasenra reaches its absorption half-life within 3.5 days. There are no meaningful differences when the drug is administered in the arm, thigh, or abdomen.

Population pharmacokinetic studies show that Fasenra has both a central and peripheral distribution. It reaches distribution volumes of 3.1 L (central) and 2.5 L (peripheral) in people weighing 154 pounds (which is about 70 kilograms).

Fasenra undergoes degradation by proteolytic enzymes throughout the body. The elimination half-life of Fasenra is approximately 15.5 days.

The systemic clearance of Fasenra is 0.29 L/day in people weighing 154 pounds (which is about 70 kilograms). Clearance of Fasenra is not impacted by renal or hepatic function, age, gender, or race. There are no known pharmacokinetic drug interactions with Fasenra.

Contraindications

The use of Fasenra is contraindicated in patients with known hypersensitivity to benralizumab or any inactive ingredient of Fasenra.

Storage

Fasenra should be refrigerated at temperatures between 36°F to 46°F (2°C to 8°C). Fasenra can be kept at room temperature for up to 14 days if necessary. If not used within that time frame, the product must be discarded.

Fasenra should be kept inside its original package and protected from light. Fasenra should not be shaken, frozen, or exposed to heat.

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 other 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.