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. Acute treatment consists of C1-INH (C1-esterase inhibitor) concentrate from donor blood, which must be administered intravenously. In an emergency, fresh frozen blood plasma, which also contains C1-INH, can also be used. However, in most European countries, C1-INH concentrate is only available to patients who are participating in special programmes. [ citation needed ] The medications ecallantide and icatibant may be used to treat attacks.  In 2017 these medications cost between 5,700 and 14,000 US$ per dose in the United States, prices that tripled in two years.  [ medical citation needed ]
Referring to the studies of Cicardi et al. (2010) and Cicardi et al. (2010) , Giavina-Bianchi et al. (2011) stated that the registration in only a few countries of formulations of C1 esterase-inhibitor concentrate is not an adequate justification to use a placebo comparison drug, and called for studies comparing icatibant and ecallantide with C1 esterase-inhibitor concentrate. Cicardi and Banerji (2011) replied that since their studies were performed in accordance with both the Declaration of Helsinki and expert consensus, they considered them ethically acceptable.