When is prophylaxis for hereditary angioedema necessary?
OBJECTIVE
To determine when newer agents, such as C1 esterase inhibitor protein (C1-INH), should be considered as prophylaxis to decrease hereditary angioedema (HAE) attacks as an alternative to androgens, which have significant adverse events.


METHODS
A literature review (PubMed, Google, and Ovid), guideline review, expert panel meeting, and group discussion were performed to decide when prophylaxis is indicated.


METHODS
Articles addressing HAE therapy published in the peer-reviewed literature were selected.


RESULTS
The retrieved studies demonstrate that C1-INH is effective and that the half-life makes it attractive for prophylactic use. The short half-lives of ecallantide, icatibant, and recombinant human C1-INH limit their use as prophylactic agents. Patients with severe anxiety, more than 1 attack per month, rapid progression of attacks, limited access to health care, more than 10 days lost from work or school per year, previous laryngeal swelling, more than 3 emergency department visits per year, more than 1 hospitalization per year, previous intubation, previous intensive care unit care, significant compromise in quality of life, or narcotic dependency should be considered for androgen or C1-INH prophylaxis therapy.


CONCLUSIONS
Patients with HAE with frequent attacks, severe attacks, past laryngeal attacks, excessive loss of work or school, significant anxiety, and poor quality of life should be considered for C1-INH prophylaxis, especially those who fail, are intolerant of, have adverse reactions to, or are not candidates for androgen therapy.
Craig
Timothy
T
Department of Medicine and Pediatrics, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania 17033, USA. tcraig@psu.edu
Riedl
Marc
M
Dykewicz
Mark S
MS
Gower
Richard G
RG
Baker
James
J
Edelman
Frank J
FJ
Hurewitz
David
D
Jacobs
Joshua
J
Kalfus
Ira
I
D000728:Androgens / Q000009:adverse effects / Q000627:therapeutic use; D054179:Angioedemas, Hereditary / Q000175:diagnosis / Q000453:epidemiology / Q000517:prevention & control*; D001920:Bradykinin / Q000009:adverse effects / Q000031:analogs & derivatives / Q000627:therapeutic use; D065168:Bradykinin Receptor Antagonists; D002986:Clinical Trials as Topic; D003174:Complement C1 Inactivator Proteins / Q000009:adverse effects / Q000235:genetics / Q000627:therapeutic use; D050718:Complement C1 Inhibitor Protein; D006801:Humans; D007610:Kallikreins / Q000037:antagonists & inhibitors; D009026:Mortality; D010455:Peptides / Q000009:adverse effects / Q000627:therapeutic use
D000728:Androgens; D065168:Bradykinin Receptor Antagonists; D003174:Complement C1 Inactivator Proteins; D050718:Complement C1 Inhibitor Protein; D010455:Peptides; C469952:SERPING1 protein, human; C511194:ecallantide; C065679:icatibant; D007610:Kallikreins; D001920:Bradykinin