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How do you administer/inject Firazyr?

Medically reviewed by Carmen Pope, BPharm. Last updated on May 3, 2023.

Official answer

  • Firazyr (icatibant) is given by subcutaneous injection (under the skin).
  • Firazyr may be administered by a health professional or people can be taught to self-administer it.
  • Firazyr treats acute angioedema attacks in adults with hereditary angioedema (HAE).
  • Firazyr works by blocking the actions of bradykinin. Bradykinin increases blood vessel permeability and is thought to be responsible for the symptoms of an acute attack of HAE.

Firazyr (icatibant) is a selective B2 bradykinin receptor antagonist indicated for the treatment of acute attacks in adults 18 years and older with hereditary angioedema (HAE).

Hereditary angioedema is a genetic disorder that causes attacks of swelling severe swelling in the limbs, face, intestinal tract, and airway.

Firazyr may be administered by a trained health professional experienced at treating HAE; however, people can also be taught how to administer it themselves.

How do you administer Firazyr?

Firazyr is given by subcutaneous (under the skin) injection into the abdominal area. A nurse or doctor should teach you how to self administer Firazyr before you try yourself alone.

  1. First, wash your hands with soap and water. Decide where you will inject the Firazyr; choose an area that is free from scars or is not bruised or painful at least 2 to 4 inches below your belly button on either side. Clean the injection site with an alcohol swab and allow to dry.
  2. Remove the prefilled syringe from the carton and remove the seal from the needle cap. Inspect the contents of the syringe. They should be clear and colorless. Do not use the injection if it contains particles, is cloudy, or an unusual color.
  3. Remove the protective cap from the end of the prefilled syringe by unscrewing the cap. Hold the syringe firmly and firmly screw the needle to the prefilled syringe containing the Firazyr.
  4. Hold the needle cap and remove the needle and syringe. Do not touch the plunger.
  5. Hold the injection like a pen and use your other hand to gently pinch the skin up on your injection site into a fold.
  6. Inject the needle into the skin fold at a 45 to 90-degree angle. Push the plunger slowly, releasing the Firazyr into the skin over at least 30 seconds.
  7. Release the skin fold and pull the needle out.
  8. Dispose of your used Firazyr syringe into an appropriate sharps container.

What is the dosage of Firazyr?

The usual dosage to treat an acute attack of angioedema is 30mg. If attack symptoms persist additional doses may be administered at intervals of at least 6 hours.

No more than 3 doses may be administered in any 24 hour period.

How does Firazyr work?

People with hereditary angioedema (HAE) have low levels of naturally occurring C1 inhibitory protein (C1-INH) in their blood. C1-INH is a key regulator of the Factor XII/kallikrein cascade that leads to the production of bradykinin. Bradykinin is thought to be responsible for the characteristic symptoms of angioedema attacks seen in HAE.

Firazyr (icatibant) blocks the bradykinin B2 receptor, to the same extent as what bradykinin would. By inhibiting the binding of bradykinin to the B2 receptor it helps treat the symptoms of an acute attack of HAE.

What is hereditary angioedema?

Hereditary angioedema is a genetic disorder characterized by severe swelling in the limbs, face, intestinal tract, and airway. There are three known types: Type I and II caused by mutations in the Serping I gene and Type III which is caused by mutations in the F12 gene.

The Serping I gene provides instructions for making the C1 inhibitor protein, which helps control inflammation. Mutations in this gene can lead to either reduced levels of C1 protein in the blood or the production of a C1 inhibitor that functions abnormally. When levels of this C1 protein are decreased, excessive amounts of another protein fragment, called bradykinin are generated. Bradykinin increases the leakage of fluid through the walls of blood vessels into body tissues, promoting inflammation. This causes fluid to accumulate which causes the swelling characteristic of hereditary angioedema type I and type II.

Some cases of hereditary angioedema type III are associated with mutations in the F12 gene. This gene codes for an important protein that helps our blood to clot, known as coagulation factor XII. Factor XII is also an important stimulator of inflammation and is involved in bradykinin production. Certain F12 mutations produce Factor XII with an increased activity, which generates more bradykinin, leading to blood vessel wall leakage and angioedema. The gene mutations responsible for other types of hereditary angioedema III have not yet been discovered.


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