Firazyr Side Effects Center

Last updated on RxList: 6/7/2022
Firazyr Side Effects Center

What Is Firazyr?

Firazyr (icatibant) is a synthetic peptide indicated for the treatment of acute attacks of hereditary angioedema (HAE) in adults over the age of 18. People with HAE can develop rapid swelling of the hands, feet, limbs, face, intestinal tract, voice box, or windpipe, which may result in disfigurement, disability, or death.

What Are Side Effects of Firazyr?

Common side effects of Firazyr include:

  • fever,
  • dizziness,
  • fatigue,
  • drowsiness,
  • tired feeling,
  • headache,
  • skin rash, or
  • injection site reactions (pain, pressure, swelling, bruising, burning, warmth, redness, numbness, tenderness, itching, rash, or irritation)

Dosage for Firazyr

Firazyr is available as a single-use, prefilled syringe for subcutaneous administration. Each mL of the solution contains 10 mg strength of icatibant. The recommended dose of Firazyr is 30 mg administered by subcutaneous injection in the abdominal area. Additional doses may be administered at intervals of at least six hours if response is inadequate or if symptoms recur.

What Drugs, Substances, or Supplements Interact with Firazyr?

No more than three doses may be administered in any 24 hour period. Firazyr may reduce the effectiveness of ACE inhibitors. Serious side effects include airway obstruction by laryngeal swelling attacks.

Firazyr During Pregnancy an d Breastfeeding

Patients should inform their doctors if they are pregnant or planning to become pregnant. It is not known if Firazyr will harm unborn babies. Women and their healthcare providers should decide together if Firazyr is the correct treatment. Patients should also inform their doctors if they are breastfeeding or if they plan to breastfeed. It is not know if Firazyr passes into breast milk. Safety and effectiveness in pediatric patients below the age of 18 years have not been established.

Additional Information

Our Firazyr Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Firazyr Consumer Information

Get emergency medical help if you have signs of an allergic reaction to this medicine: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

An allergic reaction to icatibant is unlikely to occur, but could cause symptoms that are very similar to the signs of hereditary angioedema.

Common side effects may include:

  • pain, numbness, bruising, redness, swelling, warmth, burning, irritation, hives, itching, or a feeling of pressure where the injection was given;
  • fever;
  • headache, dizziness;
  • abnormal liver function tests;
  • nausea; or
  • rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Firazyr Professional Information


Clinical Trials Experience

The safety of icatibant was evaluated in three controlled trials that included 223 patients who received FIRAZYR 30 mg (n=113), placebo (n=75), or comparator (n=38). The mean age at study entry was 38 years (range 18 to 83 years), 64% were female, and 95% were white. The data described below represent adverse reactions observed from the two placebo-controlled trials, consisting of 77 patients who received FIRAZYR at a dose of 30 mg SC, and 75 who received placebo.

The most frequently reported adverse reactions (occurring in greater than 1% of patients and at a higher rate with FIRAZYR versus placebo) are shown in Table 1.

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Table 1 Adverse reactions observed in >1% of patients with acute attacks of HAE and at a higher rate with FIRAZYR versus placebo in the placebo-controlled trialsa

System Organ Class
Preferred Term
(N =77)
(N = 75)
Subjects (%) Subjects (%)
General disorders and administration site conditions
  Injection site reactionb 75 (97) 25 (33)
  Pyrexia 3 (4) 0
  Transaminase increased 3 (4) 0
Nervous system disorders
  Dizziness 2 (3) 1 (1)
a Events occurring within 14 days of study drug administration
b Injection site bruising, Injection site hematoma, Injection site burning, Injection site erythema, Injection site hypoesthesia, Injection site irritation, Injection site numbness, Injection site edema, Injection site pain, Injection site pressure sensation, Injection site pruritus, Injection site swelling, Injection site urticaria, and Injection site warmth

The third trial was active-controlled and was comprised of 35 patients who received FIRAZYR 30 mg and 38 patients who received the comparator. Adverse reactions for FIRAZYR were similar in nature and frequency to those reported in Table 1.

In all three controlled trials, patients were eligible for treatment of subsequent attacks in an open-label extension. Patients were treated with FIRAZYR 30 mg and could receive up to 3 doses of FIRAZYR 30 mg administered at least 6 hours apart for each attack. A total of 225 patients were treated with 1,076 doses of 30 mg FIRAZYR for 987 attacks of acute HAE. Adverse reactions similar in nature and frequency were observed to those seen in the controlled phase of the trials. Other adverse reactions reported included rash, nausea, and headache in patients exposed to FIRAZYR.

The safety of self-administration was evaluated in a separate, open-label trial in 56 patients with HAE. In this trial, the safety profile of FIRAZYR in patients who self-administered FIRAZYR was similar in nature and frequency to that of patients whose therapy was administered by healthcare professionals.


Across repeated treatment in the controlled trials, 4 patients tested positive for anti-icatibant antibodies. Three of these patients had subsequent tests which were negative. No hypersensitivity or anaphylactic reactions were reported with FIRAZYR. No association between anti-icatibant antibodies and efficacy was observed.

Postmarketing Experience

The following adverse reactions have been identified during post approval use of FIRAZYR: urticaria. Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.


ACE Inhibitors

FIRAZYR is a bradykinin B2 receptor antagonist and thereby has the potential to have a pharmacodynamic interaction with ACE inhibitors where FIRAZYR may attenuate the antihypertensive effect of ACE inhibitors. Clinical trials to date have excluded subjects taking ACE inhibitors.

Read the entire FDA prescribing information for Firazyr (Icatibant Injection for Subcutaneous Administration)

© Firazyr Patient Information is supplied by Cerner Multum, Inc. and Firazyr Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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