Pronunciation: FIR-a-zeer
Generic name: icatibant
Dosage form: injection for subcutaneous use (single-dose prefilled syringe 30 mg/3 mL)
Drug class: Hereditary angioedema agents

Medically reviewed by Carmen Pope, BPharm. Last updated on Jun 30, 2025.

What is Firazyr?

Firazyr is used for hereditary angioedema (HAE) to treat acute HAE attacks in adults 18 years and older. It is given as a single subcutaneous (under the skin) injection. Firazyr may be given up to 3 times in 24 hours during an acute attack.

Firazyr relieves HAE symptoms by blocking bradykinin, a natural substance that causes swelling and pain during an HAE attack. Bradykinin normally binds to specific receptors (called B2 receptors) in your body, which opens up blood vessels and triggers inflammation. Firazyr works by attaching to these same receptors before bradykinin does, preventing it from causing its harmful effects. This helps reduce the swelling, inflammation, and pain that occur during an acute HAE attack.

Firazyr belongs to the drug class called bradykinin B2 receptor antagonists.

Firazyr (icatibant) gained FDA approval on August 25, 2011. A generic is available under the name icatibant. Approval was based on positive results from three Phase 3 clinical trials: FAST-1 (NCT00097695), FAST-2 (NCT00500656), and FAST-3 (NCT00912093), which reported:

• One injection of Firazyr was sufficient to treat 88·2% of attacks; rescue medication was required in 5·3% of attacks.
• Symptoms of HAE were relieved after an average of 2 to 2.5 hours.

Side effects

The most common side effects of Firazyr are:

• injection site reactions, such as redness, irritation, or pain at the injection site
• fever
• Increased levels of transaminase (a liver enzyme)
• dizziness
• a rash.

Serious side effects and warnings

Laryngeal attacks. You should always seek medical attention if you have a laryngeal attack, even after injecting Firazyr. Inject a dose of Firazyr and then go to the nearest hospital emergency room right away. Laryngeal attacks can become life-threatening.

Firazyr may cause an allergic reaction with symptoms similar to the signs of hereditary angioedema, such as hives, trouble breathing, or swelling of your face, lips, tongue, or throat.

Do not use more than 3 injections within 24 hours. Call your doctor if your symptoms do not improve or if they get worse after using this medication.

It is not known if Firazyr is safe in people younger than 18 years old.

Tell your healthcare provider if you have any side effect that bothers you or do not go away. These are not all of the possible side effects of this medicine. For more information, ask your healthcare provider or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Related/similar drugs

Before taking this medicine

Do not use this medicine if you are allergic to icatibant, Firazyr, or any inactive ingredients in the injection.

Before using Firazyr, tell your doctor about all your medical conditions, including if you:

• have allergies
• take any medicines, including heart or blood pressure medications
• are pregnant or intending to become pregnant
• are breastfeeding or intending to breastfeed.

Older adults may be more sensitive to the effects of this medicine.

Pregnancy

It is not known if Firazyr can harm an unborn baby.

Breastfeeding

It is not known if Firazyr passes into breast milk.

How should I use Firazyr?

Read the Instructions for Use at the end of the Firazyr Package Insert for detailed instructions about the correct way to use this medicine.

Use Firazyr exactly as your healthcare provider tells you to. You or your caregiver should know how to give Firazyr before you actually have an HAE attack, so that you can respond right away. 

• Firazyr is injected subcutaneously into the abdominal area as a single dose of 30 mg (1 prefilled syringe).
• If your response to Firazyr is inadequate or your symptoms recur, then you may give an additional injection of 30 mg after an interval of at least 6 hours.
• Do not administer more than 3 Firazyr injections within 24 hours.
• Call your doctor if your symptoms do not improve or if they get worse after using this medicine.

If you have a laryngeal attack, inject 1 dose of Firazyr and then go to the nearest hospital emergency room right away.

How to inject Firazyr

Wash your hands with soap and water before preparing your injection.

Prepare an injection only when you are ready to give it. Do not use the medicine if it has changed colors, looks cloudy, or has particles in it. Call your pharmacist for a new medicine.

• Remove the prefilled syringe and needle from the carton.
• Twist the needle cap to break the seal. The needle should remain inside the protective needle cap. Screw the needle on the prefilled syringe.
• Choose your injection site. This should be a fold of skin on your stomach, about 2 to 4 inches (5 to 10 cm) below your belly button on either side.
• Do not inject Firazyr into an area that is painful, swollen, scarred, or bruised.
• Clean the site with an alcohol swab and allow it to dry.
• Remove the needle from the needle cap.
• Hold the syringe in your hand between your fingers and thumb.
• Use your other hand to gently pinch up the fold of skin.
• Hold the syringe at a 45 to 90-degree angle to your skin and quickly insert the needle into the skin fold.
• Push the plunger at the top of the syringe for at least 30 seconds until no Firazyr is in the syringe.
• Release the skin fold and gently remove the needle.
• Dispose of your used prefilled syringe in an FDA-cleared sharps disposal container. Follow state or local laws about how to dispose of this container. Keep it out of the reach of children and pets.

See How do you administer/inject Firazyr for more information.

Each prefilled syringe is for one use only. Throw it away after one use, even if there is still medicine left inside.

Dosing information

Usual Adult Dose of Firazyr for Acute Attack of HAE:

• Initial dose: 30 mg (1 prefilled syringe) SC into the abdominal area.
• 6+ hours later (if symptoms unresolved/recur): 30 mg (1 prefilled syringe) SC into the abdominal area.
• 6+ hours later (if symptoms unresolved/recur): 30 mg (1 prefilled syringe) SC into the abdominal area.
• Maximum dose: 90 mg/24 hours (3 injections).

What happens if I miss a dose?

Since Firazyr is used when needed, it does not have a daily dosing schedule. Call your doctor if your symptoms do not improve after using this medicine.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include redness, itching, or feeling like you might pass out.

What should I avoid after using Firazyr?

Tiredness, drowsiness, and dizziness can happen in people who take Firazyr. If this happens, do not drive a car, use machinery, or do anything that requires you to be alert.

Storage

Store the prefilled syringe in its original container in a refrigerator or at room temperature. Do not freeze.

What other drugs will affect Firazyr?

Tell your doctor about all your other medicines, especially heart or blood pressure medication.

Other drugs may interact with icatibant, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Ingredients

Active ingredient: icatibant acetate
Inactive ingredients: sodium chloride (isotonicity reagent), glacial acetic acid (pH adjuster), sodium hydroxide (pH adjuster), and water.

Firazyr is available as a 10 mg/mL injection.

Who makes Firazyr?

Firazyr is made by Shire Orphan Therapies GmbH and distributed by Takeda Pharmaceuticals America, Inc.

Frequently asked questions

• How long does Firazyr take to work?
• How do you administer/inject Firazyr?
• What is Firazyr used for?

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer