Hereditary Angioedema - Acute Treatment

Acute Treatment

The aim of acute treatment is to halt progression of the edema as quickly as possible, which can be life-saving, particularly if the swelling is in the larynx. In Germany, most acute treatment consists of C1 inhibitor concentrate from donor blood, which must be administered intravenously; however, in most European countries, C1 inhibitor concentrate is only available to patients who are participating in special programs. In emergency situations where C1 inhibitor concentrate is not available, fresh frozen plasma (FFP) can be used as an alternative, as it also contains C1 inhibitor.

Other treatment modalities can stimulate the synthesis of C1 inhibitor, or reduce C1 inhibitor consumption. Purified C1 inhibitor, derived from human blood, has been used in Europe since 1979. Several C1 inhibitor treatments are now available in the U.S. Food and Drug Administration and two C1 inhibitor products are now available in Canada. Berinert P (CSL Behring), which is pasteurized, was approved by the F.D.A. in 2009 for acute attacks. Cinryze (ViroPharma), which is nanofiltered, was approved by the F.D.A. in 2008 for prophylaxis. Rhucin (Pharming) is a recombinant C1 inhibitor under development that does not carry the risk of infectious disease transmission due to human blood-borne pathogens.

Newer treatments attack the contact cascade. Ecallantide (Kalbitor, Dyax) inhibits plasma kallikrein, and was approved by the F.D.A. (but not in Europe) for acute attacks in 2009. Icatibant (Firazyr, Jerini) inhibits the bradykinin B2 receptor, and was approved in Europe. Approved by the FDA on August 25, 2011. In hereditary angioedema, specific stimuli that have previously led to attacks may need to be avoided in the future. It does not respond to antihistamines, corticosteroids, or epinephrine.