How Icatibant Injection Works

Generic Icatibant Injection works in the same way that Firazyr®* does. It is a selective bradykinin type 2–receptor antagonist.

What does that mean?

People with Hereditary angioedema (HAE) can enter into an uncontrolled production of a protein called bradykinin. Bradykinin binds to the receptor, B2, found on the lining of blood vessels. When bradykinin is bound to the B2 receptor, the blood vessels vasodilate and allow fluid to pass through leading to swelling.

Untreated HAE patient during an attack

HAE patient after Icatibant Injection treatment

After Icatibant Injection is administered, the drug attaches to the B2 receptor, blocking bradykinin from attaching to it and thereby preventing further vasodilation.

Potential Side Effects of Icatibant Injection11

The most common side effects of Icatibant Injection include:

  • Redness, bruising, swelling, warmth, burning, itching, irritation, hives, numbness, pressure, or pain at the injection site
  • Fever
  • Too much of an enzyme called transaminase in your blood
  • Dizziness
  • Nausea
  • Headache
  • Rash

Tell your healthcare provider if you have any side effect that bothers you or that does not go away. These are not all of the possible side effects of Icatibant Injection. For more information, ask your healthcare provider or pharmacist.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or visit

For more information, see the Full Prescribing Information, including the Patient Information.


  • [11] Icatibant Injection Prescribing Information. Fresenius Kabi USA, LLC; 2020.

*FIRAZYR® is a registered trademark of Shire, a Takeda company.