C1 Esterase Inhibitor
You should talk with your healthcare provider prior to using this medication if you have:
- Been treated with a C1 esterase inhibitor in the past and had a reaction to it
- Ever had a stroke, transient ischemic attack (TIA or mini-stroke), heart attack, or blood clot
- Any allergies, including to foods, dyes, or preservatives.
Also, let your healthcare provider know if you are:
- Pregnant or thinking of becoming pregnant (see C1 Esterase Inhibitor and Pregnancy)
- Breastfeeding (see C1 Esterase Inhibitor and Breastfeeding).
Make sure to tell your healthcare provider about all other medications you are taking, including prescription and nonprescription medicines, vitamins, and herbal supplements.
(Click Precautions and Warnings With C1 Esterase Inhibitor to learn more, including information on who should not use the drug.)
HAE is caused by a defect in the gene that controls a protein known as C1 inhibitor. C1 inhibitor helps regulate certain complex reactions in the body, including reactions that lead to the production of bradykinin. Bradykinin is a chemical that causes blood vessels to dilate (widen) and leak fluid into surrounding tissue. It is this leakage of fluid that is thought to cause the swelling and painful attacks associated with HAE.
In people with HAE, the body either does not produce enough C1 inhibitor, or produces C1 inhibitor that does not function properly. As a result, too much bradykinin is produced, blood vessels leak fluid, and swelling and painful attacks can occur.
C1 esterase inhibitor works by replacing C1 inhibitor that is missing or not working properly in people with HAE.