Also known as benralizumab

Key points about Fasenra

  • Fasenra is used to treat a type of severe asthma called eosinophilic asthma.
  • Fasenra is also called benralizumab. 
  • Find out how it is used and possible side effects.
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Fasenra is used to treat severe type of asthma called eosinophilic asthma. This is when there are too many eosinophils (a type of disease-fighting white blood cell) in their blood and lungs. Too many eosinophils can cause asthma flare-ups. This type of asthma is rare, and generally occurs in adults. Fasenra works by reducing the number of eosinophils produced. This has the effect of reducing your symptoms during an asthma attack and how often you get asthma flare-ups. 

Fasenra does not give immediate relief from an asthma attack
If you have an asthma action plan that you have agreed with your doctor, follow it closely at all times.
For severe asthma symptoms, you should use your reliever inhaler immediately and call an ambulance on 111 or go to your nearest Accident & Emergency clinic.

In Aotearoa New Zealand Fasenra is available as an injection given under your skin. Fasenra comes as a single-use pen injection, which means that each pen is used only once for 1 injection. The pen is ready to use meaning it's pre-filled with the medicine, and the needle is already fitted onto the pen. The pen is very easy to use – you don't need to measure or mix anything, or handle a needle.

  • The usual dose of Fasenra is a 30 mg (one prefilled syringe) injection every 4 weeks for the first 3 doses, then one injection every 8 weeks after that.
  • On the day of your injection, take your asthma medication as usual.
  • If you have missed a dose of Fasenra contact your doctor, nurse, or pharmacist as soon as possible. They will tell you what you need to do.

Fasenra injection is given under your skin (called subcutaneous). If you are injecting it by yourself, give it in your thigh or abdomen. If the injection is given by someone else (for example a caregiver or your doctor, nurse or pharmacist), it may also be given in the upper arm. Don't try to inject yourself in the arm.

Store Fasenra in the fridge, in the original package. Don't freeze it – if your pen has been frozen, don't use it. Take your Fasenra pen out of the fridge and leave it at room temperature for about 30 minutes before injecting. Don't warm Fasenra in any other way, eg, in the microwave or hot water. When refrigeration isn't possible (eg, when you are on holiday), you can keep your pen at room temperature (20°C to 25°C ) for up to 14 days.

It's important to get rid of your used injection pens safely.

  • Keep them out of reach of children and pets, and places where they could hurt others. You can do this by buying a sharps container from your pharmacy. This is a special container made of hard plastic that has a tight-fitting lid so used needles and syringes can be stored securely.
  • Don't flush used needles and syringes down the toilet or put them in household or public rubbish or recycle bins. Once your sharps container is full, take it to your pharmacy for safe disposal.

Like all medicines, Fasenra can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Pain and discomfort at the injection site including redness, swelling, itching and a burning sensation of the skin near where the injection was given
  • This is quite common.
  • This usually passes with time. 
  • Tell your doctor if this bother you.
  • Headache
  • Sore throat
  • Fever (high temperature)
  • These are common.
  • This usually passes with time. 
  • Tell your doctor if these bother you.
  • Signs of an allergic reaction such as skin rash, itching, swelling of your lips, face, and mouth or difficulty breathing
  • Tell your doctor immediately or call 111 for an ambulance. 
For more information on side effects, see the Medsafe consumer information leaflet Fasenra.(external link)

Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product.(external link)

The following links provide further information on Fasenra.

Medsafe Consumer Information Sheets: Fasenra(external link)


  1. Benralizumab(external link) New Zealand Formulary


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Credits: Healthify He Puna Waiora Pharmacists. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

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