Get emergency medical help if you have signs of an allergic reaction to Firazyr: 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 Firazyr side effects may include:
pain, numbness, bruising, redness, swelling, warmth, burning, irritation, hives, itching, or a feeling of pressure where the injection was given;
drowsiness, tiredness;
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.
 Firazyr side effects (more detail)
