Angiotensin-Converting Enzyme Inhibitor-associated Angioedema Treated with c1-esterase Inhibitor: A Case Report and Review of the Literature

Case Report: A 59-year old man currently on >5 years of angiotensin-converting enzyme inhibitor (ACEI) therapy presented to the emergency department with angioedema of the tongue and difficulty swallowing. After receiving conventional therapy of antihistamine, steroids, and epinephrine, the patient's condition continued to deteriorate, with imminent intubation. The patient was treated with a C1-esterase inhibitor (C1-INH) and experienced rapid resolution of symptoms, which avoided airway complications. Discussion: Although no therapy has been approved for the treatment of ACEI–associated angioedema (AAE), the conventional therapy (antihistamine, steroids, and epinephrine) often proves ineffective in this bradykinin-mediated angioedema. There are drugs approved and used for hereditary angioedema that may be effective in the acute phase of ACEI-AAE that may prevent the need for further interventions, such as intubation and tracheotomy. These drugs include icatibant, ecallantide, fresh frozen plasma, and C1-INH. Conclusion: The literature and clinical evidence indicate C1-INH can be effectively used in the treatment of ACEI-AAE to halt the progression of the condition, prevent airway compromise and the need for intervention, and lead to rapid resolution of symptoms.