Fasenra dosage, forms, and strengths

Fasenra is a prescription, brand-name maintenance for severe eosinophilic asthma, characterized by high numbers of white blood cells called eosinophils. The active ingredient in Fasenra is benralizumab, a monoclonal antibody. It reduces the number of eosinophils in the body, helping to prevent asthma attacks. Administered as an injection under the skin every eight weeks, Fasenra and other asthma maintenance and rescue medications like inhalers or corticosteroids are used. Healthcare professionals typically don’t prescribe Fasenra or similar biologic medications until current treatments fail to prevent asthma attacks adequately.

Fasenra forms and strengths

Fasenra comes in one dosage form. It is an injection administered under the skin (subcutaneous injection) by patients or their caregivers using a single-dose autoinjector. Healthcare providers use a single-dose Fasenra prefilled syringe to administer injections. 

• Injection pen: 10 mg/0.5 mL (pediatric use), 30 mg/mL

• Prefilled syringe: 30 mg/mL

Fasenra dosage for adults

The U.S. Food and Drug Administration (FDA) has approved Fasenra as an add-on maintenance treatment for adults and children with severe asthma of the eosinophilic phenotype, the most common form of severe asthma. After receiving three starting injections four weeks apart, patients will transition to one injection every eight weeks. 

Fasenra is only right for some. Anyone who has had an allergic reaction such as hives, angioedema, or anaphylaxis to its active ingredient, benralizumab, or any other ingredients (excipients) will not be able to use Fasenra. 

Although not a contraindication, anyone infected with parasite worms (helminth infection) cannot start Fasenra treatment until that parasitic infection resolves.

Fasenra dosage for severe eosinophilic asthma

Eosinophilic asthma, or e-asthma, is a way that healthcare providers classify asthma. Although healthcare professionals believe only a minority of asthma patients have eosinophilic conditions, they account for half of all severe asthma cases, maybe even as much as 84%.

Healthcare providers classify asthma as either allergic or non-allergic and eosinophilic or non-eosinophilic. People with eosinophilic asthma can be diagnosed with eosinophilic allergic asthma or eosinophilic non-allergic asthma. When a doctor diagnoses eosinophilic asthma, it indicates high blood and sputum levels of a specific type of white blood cells called eosinophils. These immune system cells produce the type of inflammatory response most commonly associated with severe asthma.

To prevent eosinophilic asthma attacks, Fasenra contains a monoclonal antibody called benralizumab. Healthcare professionals aren’t certain about the benralizumab’s exact mechanism of action, but they know it attaches itself to a receptor molecule on the surface of eosinophils called interleukin-5. By doing so, benralizumab “paints a target” on eosinophils. Other white blood cells in the immune system then kill them, so the ultimate effect of benralizumab is to reduce blood eosinophil counts. 

Asthma specialists typically do not use biologic drugs like Fasenra except in severe asthma cases that are not being controlled by other maintenance treatments. Fasenra is never used alone. Patients will still need daily maintenance treatments, such as inhalers or corticosteroids, though corticosteroid doses may be reduced or discontinued after Fasenra becomes effective.

Fasenra is an injection administered under the skin (subcutaneously). It can be self-administered, or a caregiver or healthcare provider can administer it. People will receive doses four weeks apart for the first three when treatment starts. After that, injections are only needed every eight weeks.

• Standard Fasenra dosage for severe eosinophilic asthma: 30 mg subcutaneous injection administered every eight weeks

• Maximum Fasenra dose for severe eosinophilic asthma: 30 mg subcutaneous injection 

Fasenra dosage for children

The FDA has approved Fasenra as an add-on maintenance treatment for severe eosinophilic asthma in children 6 and older. Children will receive one of two doses: a pediatric dose of 10 mg or an adult dose of 30 mg. The choice is determined by body weight. As with adults, children will start with three monthly injections: one at the beginning, another one four weeks later, and a third one at eight weeks. They will then only need injections every eight weeks.

Fasenra dosage restrictions

There are no dosage modifications necessary for people with liver disease (hepatic impairment), kidney dysfunction (renal impairment), or other medical conditions.

How to take Fasenra

Patients or their caregivers can give Fasenra injections at home using the Fasenra Pen. Always carefully review the Instructions for Use in the Fasenra package before giving a Fasenra shot. Here’s a summary:

GENERAL DIRECTIONS:

• Take Fasenra as directed by the prescriber. 

• Do not administer injections until you’ve received training from a healthcare provider. The Fasenra website has video instructions that can help people review the procedure for administering Fasenra.

• Please read the Patient Information and Instructions for Use before administering an injection.

• Fasenra is for subcutaneous use only. Never inject Fasenra into a vein.

WHERE TO INJECT:

• Patients can self-administer Fasenra injections into the skin on the lower stomach area or the front of the thighs.

• Caregivers can inject the medicine into the outer upper arms, the lower stomach area, or the front of the thighs.

• Pick a different injection site for each injection.

• Do not inject the medicine into red, hard, scaly, scarred, or bruised skin.

PREPARING FOR THE INJECTION:

• Take the carton out of the refrigerator. Unopened, let it sit at room temperature for 30 minutes. Do not heat it. 

• Wash your hands with soap and water.

• Clean the injection site with an antiseptic wipe. 

• Carefully remove the Fasenra Pen from the package. Do not shake it.

• Do not use the pen if it appears damaged or the expiration date has passed.

• Inspect the medicine to make sure it is clear to light yellow. Do not use the pen if the medicine is discolored, cloudy, or contains large particles. It’s okay if the medicine contains small white particles or air bubbles.

ADMINISTERING THE INJECTION:

• Carefully remove the cap.

• Hold the pen barrel between your fingers and your thumb with the medicine window visible.

• You may squeeze the skin at the injection site, but it’s unnecessary.

• Position the injector at a 90˚ angle above the injection site with the needle facing the skin.

• Press and hold the injector firmly onto the skin’s surface.

• The pen will click when the injection starts. The green plunger will gradually fill the medicine window.

• The pen will click a second time when the injection is finished.

• Lift the pen straight up.

• The green plunger should fill the window if it doesn’t, call the prescriber.

• Dispose of the autoinjector in a sharps container.

STORING FASENRA:

• Store Fasenra in the refrigerator in its original unopened carton. Do not freeze.

• Do not put the package back in the refrigerator if it has been taken out of the refrigerator and allowed to warm to room temperature.

• Fasenra can be stored in its original package at room temperature for up to 14 days. 

Fasenra dosage FAQs

How long does it take Fasenra to work?

Fasenra reduces the incidence of asthma flare-ups, so its success is measured in months and years. In clinical studies, people showed their best results in the fifth year of treatment. Most people should notice improvement faster than that. In clinical trials, people had improved lung function at least four weeks after the first dose.

How long does Fasenra stay in your system?

With a half-life averaging 15 days, a benralizumab dose is cleared from the body in about 75 days (eight weeks).

What happens if I miss a dose of Fasenra?

Call the prescribing asthma specialist or doctor for advice if a Fasenra dose is missed or forgotten.

How long can you take Fasenra?

Fasenra is intended for long-term use. Clinical trials lasted as long as one year, and some continued for another two years. No side effects due to long-term use were identified in these studies.

How do I stop taking Fasenra?

Do not stop taking Fasenra until the prescribing doctor has been consulted. Stopping Fasenra will not cause withdrawal symptoms, but the prescriber may need to start another medication to prevent asthma exacerbations.

Side effects are relatively minimal, but people may need to stop Fasenra if it doesn’t work or if they experience an allergic reaction. In that case, the prescriber can turn to other biologic drugs that also work at preventing asthma exacerbations in people with severe and uncontrolled asthma in the presence of eosinophils. These other antibody drugs include:

• Nucala (mepolizumab)

• Dupixent (dupilumab)

• Cinqair (reslizumab)

• Tezspire (tezepelumab)

What is the maximum dosage for Fasenra?

The maximum dose of Fasenra is 30 mg. Doses are spaced four weeks apart at the beginning of therapy, and (after 3 doses are given) it is then given eight weeks apart.

Can you overdose on Fasenra?

In clinical trials, large overdoses of Fasenra did not cause problems. An overdose is extremely unlikely. Doses are administered every eight weeks. People purchase one single-dose dose injector pen at a time, and healthcare providers use single-dose prefilled syringes.

What interacts with Fasenra?

Fasenra has no known drug interactions. Even so, make sure to tell the prescriber and the pharmacist about all the medications and supplements you are taking, especially oral or inhaled corticosteroids. 

Do not stop taking inhaled or oral corticosteroids when getting Fasenra injections unless the doctor tells you to. 

What happens when you mix Fasenra and alcohol?

Alcohol does not interact with Fasenra. However, people with asthma should get medical advice from their asthma specialist or other healthcare professional about drinking alcohol. In some people, alcohol is a significant trigger of asthma symptoms. 

Is it safe to take Fasenra during pregnancy?

Fasenra has not been studied in pregnant women, so healthcare professionals don’t know if it causes birth defects or other pregnancy problems. The active ingredient, benralizumab, crosses the placenta and may affect the fetus in the third trimester, but more research is needed to understand the effect. If you take Fasenra and are pregnant or may become pregnant, talk to your healthcare provider, as uncontrolled severe asthma has a higher risk of becoming hypoxic and developing pre-eclampsia.

Is it safe to take Fasenra while breastfeeding?

Healthcare professionals don’t know if Fasenra affects lactation or a nursing baby, but they believe it’s safe. Benralizumab is likely present in human breast milk, but the baby’s digestive system is expected to break it down. Again, women who are breastfeeding should get medical advice from the prescriber.

Sources

• Alcoholic drinks: Important triggers for asthma, The Journal of Allergy and Clinical Immunology

• Asthma, StatPearls

• Asthma Guideline Updates, ACSAP 2022

• Fasenra, AstraZeneca

• Fasenra benralizumab injection prescribing information, DailyMed (NIH National Library of Medicine)

• Fasenra drug summary, Prescriber’s Digital Reference (PDR)

• Fasenra HCP, AstraZeneca

• Global strategy for asthma management and prevention, Global Initiative for Asthma