Treatment of ACEI-related angioedema with icatibant: a case series

Tenecteplase-associated orolingual angioedema: A case report and literature review

PURPOSE

Orolingual angioedema (OA) secondary to administration of thrombolytic therapy is a rare, but serious, known adverse effect. Despite the lack of robust evidence for their use, C1 esterase inhibitors are recommended by guidelines for the treatment of refractory thrombolytic-associated OA. This report highlights the use of a C1 esterase inhibitor in a patient with tenecteplase-associated OA unresolved by antihistamine and corticosteroid therapy.

SUMMARY

A 67-year-old white male with a history of hypertension managed with lisinopril presented to the emergency department with acute onset of slurred speech and left-sided hemiparesis. Following workup, an outside hospital's neurology stroke team suspected an acute infarct and determined the patient to be a candidate for tenecteplase. Approximately 1 hour after tenecteplase administration, the patient began complaining of dyspnea and mild oral angioedema. Immediate interventions for OA management included intravenous therapy with dexamethasone 10 mg, diphenhydramine 25 mg, and famotidine 20 mg. After an additional 30 minutes, the patient's OA symptoms continued to progress and a C1 esterase inhibitor (Berinert) was administered. Shortly after administration of the C1 esterase inhibitor, the patient's symptoms continued to worsen, ultimately leading to endotracheal intubation. Following intubation, symptom improvement was noted, and the patient was safely extubated after 30 hours.

CONCLUSION

Although rare, OA is a potentially life-threatening complication of tenecteplase therapy and requires prompt pharmacological intervention to optimize patient outcomes. Currently, no single agent or treatment algorithm exists that has shown significant efficacy or safety in the setting of thrombolytic-associated OA. Until data are available for C1 esterase inhibitors in this application, these inhibitors should only be considered if there is continued symptom progression after intravenous administration of corticosteroids and antihistamines.

A challenging case of bradykinin-mediated angioedema with airway obstruction: management and therapeutic strategies

Angioedema is a potentially life-threatening condition that can have an allergic origin, usually mediated by histamine or a non-allergic origin, mediated by bradykinin. The distinction between these origins may present a clinical challenge at first approach, especially in cases that appear as an emergency and the outcome is time dependent. The authors describe a rare case of bradykinin angioedema associated with airway obstruction and discuss the right approach and therapeutic options. A 46-year-old patient under ACE inhibitor, renin-angiotensin-aldosterone blocker and beta blocker presented with difficulty swallowing, shortness of breath and angioedema, associated with inspiratory stridor, incapacity of talking, plantar pruritus and vomits minutes after ingestion of shrimp. The symptoms did not respond to epinephrine, anti-histamines or steroids. The airway quickly became an emergency and the authors discuss the importance of airway obstruction management and having a multidisciplinary well-defined plan of approach with backup plans. Exuberant angioedema persisted leading to the suspicion of drug induced angioedema. Treatment with tranexamic acid 1g 6/6h and icatibant 30 mg 6/6h (3 doses) was started with resolution. In these cases, the rapid institution of the right pharmacological line will relate significantly to a better outcome. It is particularly important because, as their underlying physiopathologic mechanism differ, bradykinin mediated angioedema does not respond to drugs that histamine mediated angioedema does, like corticosteroids and antihistaminic. In severe and life-threatening cases icatibant and tranexamic acid have proven to be an effective therapy.

Bradykinin Metabolism and Drug-Induced Angioedema

Bradykinin (BK) metabolism and its receptors play a central role in drug-induced angioedema (AE) without urticaria through increased vascular permeability. Many cardiovascular and diabetic drugs may cause BK-mediated AE. Angiotensin-converting enzyme inhibitors (ACEIs) and neprilysin inhibitors impair BK catabolism. Dipeptidyl peptidase-IV (DPP-IV) inhibitors reduce the breakdown of BK and substance P (SP). Moreover, angiotensin receptor blockers, thrombolytic agents, and statins may also induce BK-mediated AE. Understanding pathophysiological mechanisms is crucial for preventing and treating drug-induced AE.

Profile of serious angioedema requiring an urgent advice from a national reference call center

Angioedema (AE) is a reason for emergency care when it is severe. Care is difficult when the diagnostic is not known before the attack: mast cell (MC) or bradykinin (BK) mediated. One is very common but often benign, the other rare but potentially fatal. The French national reference center of angioedema (CREAK) provides emergency physicians with a hotline and a guideline to help them manage their patients. This study aimed to describe the clinical features of AE episodes prompting a call on the CREAK hotline and classify patients depending on the suspected cause of the AE. This is a retrospective study between March and August 2019. Each physician calling on the CREAK hotline was asked to fill a clinical description form for the AE emergency. Known patients of CREAK was excluded. Eighty four patients were included. Forty one (48.8%) in the angiotensin converting enzyme inhibitors induced acquired angioedema (ACEi-AAE), 39 (46.4%) in the mast cell induced angioedema, and 4 (4.8%) in the Bradykinin mediated angioedema. The mast cell induced angioedema patients have more history of hives (29.3%) than ACEi-AAE (2.4%, P = .0004). ACEi-AAE mainly affected the tongue (58.5% vs 25.6%, P = .003) and larynx (29.3% vs 13%, P = .001). In 65.5% of cases, the etiological diagnosis was not mentioned by the appellant, but made by the hotline. In 31% of cases, the hotline suggested the administration of a specific treatment not previously provided by the caller. All the doctors who called the hotline appreciate this tele-expertise especially in case of ACEi-AAE presumptions. In addition to providing rapid AE expertise, this service also allows to educate physicians in the management of AE irrespective of its origin.

A multicenter, open-label, randomized, proof-of-concept phase II clinical trial to assess the efficacy and safety of icatibant in patients infected with SARS-CoV-2 (COVID-19) and admitted to hospital units without invasive mechanical ventilation: study protocol (ICAT-COVID)

BACKGROUND

COVID-19 has quickly become a global pandemic with a substantial number of deaths and is a considerable burden for healthcare systems worldwide. Although most cases are paucisymptomatic and limited to the viral infection-related symptoms, some patients evolve to a second phase, with an impaired inflammatory response (cytokine storm) that may lead to acute respiratory distress syndrome and death. This is thought to be caused by increased bradykinin synthesis.

METHODS

ICAT-COVID is a multicenter, randomized, open-label, proof-of-concept phase II clinical trial assessing the clinical efficacy and safety of adding icatibant to the standard of care in patients hospitalized with COVID-19 without invasive mechanical ventilation. Patients hospitalized with a confirmed COVID-19 pneumonia diagnosis (RT-PCR or antigen test ≤ 10 days prior to randomization, and radiographic evidence of pulmonary infiltrates), rated "4" or "5" on the WHO's clinical status scale, are eligible. Patients will be randomized on a 1:1 ratio to either standard of care-plus-icatibant (experimental group) or to standard of care alone (control group). The experimental group will receive 30 mg of icatibant subcutaneously 3 times a day for 3 days (for a total of 9 doses). The expected sample size is 120 patients (60 per group) from 2 sites in Spain. Primary outcomes are the efficacy and safety of Icatibant. The main efficacy outcome is the number of patients reaching grades "2" or "1" on the WHO scale within 10 days of starting treatment. Secondary outcomes include "long-term efficacy": number of patients discharged who do not present COVID-19-related relapse or comorbidity up until 28 days after discharge, and mortality.

DISCUSSION

Icatibant, a bradykinin type 2 receptor antagonist with proven effectiveness and safety against hereditary angioedema attacks, may be beneficial for COVID-19 patients by inhibiting bradykinin's action on endothelial cells and by inhibiting the SARS-CoV-2 M protease. Our working hypothesis is that treatment with standard of care-plus-icatibant is effective and safe to treat patients infected with SARS-CoV-2 admitted to hospital for pneumonia without invasive mechanical ventilation.

TRIAL REGISTRATION

EudraCT 2020-002166-13.

CLINICALTRIALS

gov NCT04978051.

Bradykinin-induced angioedema in the emergency department

Background

Acute airway angioedema commonly occurs through two distinct mechanisms: histamine- and bradykinin-dependent. Although they respond to distinct treatments, these two potentially life-threatening states present similarly. Poor recognition of the bradykinin-dependent pathway leads to treatment errors in the emergency department (ED), despite the availability of multiple pharmacologic options for hereditary angioedema (HAE) and other forms of bradykinin-induced angioedema. Here, we consider the pathophysiology and clinical features of bradykinin-induced angioedema, and we present a systematic literature review exploring the effectiveness of the available therapies for managing such cases.

Methods

PubMed searches using ‘emergency’, ‘bradykinin’ and various therapeutic product names identified studies reporting the efficacy of treatments for bradykinin-induced angioedema in the ED setting. In all, 22 studies met prespecified criteria and are analysed here.

Findings

Whereas histamine-induced angioedema has a faster onset and often presents with urticaria, bradykinin-induced angioedema is slower in onset, with greater incidence of abdominal symptoms. Acute airway angioedema in the ED should initially be treated with anaphylactic protocols, focusing on airway management and treatment with epinephrine, antihistamine and systemic steroids. Bradykinin-induced angioedema should be considered if this standard treatment is not effective, despite proper dosing and regard of beta-adrenergic blockade. Therapeutics currently approved for HAE appear as promising options for this and other forms of bradykinin-induced angioedema encountered in the ED.

Conclusion

Diagnostic algorithms of bradykinin-induced angioedema should be followed in the ED, with early use of approved therapies to improve patient outcomes.

Initial characteristics and follow-up of patients with a diagnosis of angiotensin-converting enzyme inhibitor induced angioedema

Background: A differential diagnosis between angiotensin-converting enzyme inhibitor (ACEi) angioedema (AE) and histaminergic AE (hAE) might be challenging. Follow-up data may help discriminate these conditions but are scarcely reported. Objective: To report on the follow-up of patients with suspected ACEi-AE and to describe the baseline characteristics of AE attacks in patients with a diagnosis of ACEi-AE after follow-up. Methods: Sixty-four patients with suspected ACEi-AE (i.e., with exposure to ACEi before the first attack, no urticaria associated, and normal C1-inhibitor levels) and at least one follow-up visit were included. Data were retrospectively collected at baseline and during the follow-up. Results: After the follow-up, the diagnosis of ACEi-AE was probable in only 30 patients. The remaining patients were reclassified as having probable hAE (21 patients) or undetermined-mechanism AE (13 patients). Patients with ACEi-AE were mostly men (61%), with a median age of 64 years (interquartile range [IQR] ±17 years), with a highly variable delay from ACEi introduction (median: 23 months; interquartile range: 103 months). Attacks preferentially involved lips (50%), tongue (47%), and throat (30%). Interestingly, patients with probable ACEi-AE after a follow-up also frequently presented with a history of allergy and atopic conditions (20%), attacks with preferential evening onset (25%), and spontaneous resolution in < 24 hours (26%), which are usually considered as suggestive of hAE. ACEi-AE attacks responded to icatibant in 79% of the patients. Conclusion: Patients with probable ACEi-AE were mostly men with facial involvement. A third of the patients with an initial suspected diagnosis of ACEi-AE had a final diagnosis of probable hAE. Although a follow-up of all patients should be a standard of care, it is critical to the correct diagnosis in the case of suspected bradykinin-associated AE, which may actually be due to histamine.

Angiotensin-converting enzyme inhibitor induced angioedema: not always a class effect? A case report and short narrative review

INTRODUCTION

Bradykinin-mediated angioedema is a rare but potentially fatal adverse event. Angioedema induced by angiotensin-converting enzyme (ACE) inhibitors is generally attributed to an inhibition of bradykinin degradation following ACE inhibition. Clinical studies on ACE inhibitors mainly focus on their efficacy. Few examine their potential to generate undesirable adverse effects, particularly with regard to angioedema.

CASE DESCRIPTION

We report here a case of angioedema occurring after ramipril initiation in a patient chronically treated with quinapril. Angioedema subsided spontaneously after ramipril discontinuation and quinapril reintroduction.

DISCUSSION AND CONCLUSIONS

Our clinical case suggests that despite similar pharmacodynamic properties, quinapril and ramipril do not have the same potential to generate angioedema. To explain this difference, we suggest a potentiation of the effect of bradykinin at the B2 receptor level by ramipril, which does not occur with quinapril. Consequently, angioedema may not always be a class effect of ACE inhibitors.

What's New in the Treatment of Urticaria and Angioedema

Chronic urticaria and angioedema are diseases often managed by Allergy and Immunology specialists. Recent international guidelines have outlined a stepwise approach to management of patients using dose escalation of second-generation antihistamines followed by use of omalizumab and finally cyclosporine in more refractory cases. In select patients (those with refractory chronic urticaria), nonbiologic alternative medications with anti-inflammatory or immunosuppressant activity may be considered. Angioedema without wheals may have several different pathophysiologic mechanisms. Optimal management of mast cell-mediated angioedema is less clear but is often managed similar to chronic spontaneous urticaria. Drug-induced angioedema due to angiotensin-converting enzyme inhibitors is a common cause of angioedema in the emergency department. Although bradykinin is thought to be a primary mediator for this type of angioedema, studies of targeted therapies have been generally disappointing. In contrast, several targeted therapies have been proven successful using acute and preventive approaches for management of hereditary angioedema. Further developments, including novel biologics, novel oral therapies, and gene therapy approaches, may hopefully continue to broaden therapeutic options to ensure optimal individual management of patients with hereditary angioedema.

Clinical Practice Statement: What is the Emergency Department Management of Patients with Angioedema Secondary to an ACE-Inhibitor?

BACKGROUND

Angioedema is a complication that has been reported in up to 1.0% of individuals taking angiotensin-converting enzyme inhibitors (ACE-Is). Importantly, the onset of angioedema can occur anywhere from hours to several years after initiation of therapy with ACE-Is. Although most cases of ACE-I-induced angioedema (ACE-I-AE) are self-limiting, a major clinical concern is development of airway compromise, which can potentially require emergent airway management. The underlying pathophysiology of ACE-I-AE is incompletely understood, but is considered to be due in large part to excess bradykinin. Numerous medications have been proposed for the treatment of ACE-I-AE. This article is an update to the 2011 Clinical Practice Committee (CPC) statement from the American Academy of Emergency Medicine.

METHODS

A literature search in PubMed was performed with search terms angioedema and ACE inhibitors from August 1, 2012 to May 13, 2019. Following CPC guidelines, articles written in English were identified and then underwent a structured review for evaluation.

RESULTS

The search parameters resulted in 323 articles. The abstracts of these articles were assessed independently by the reviewers, who determined there were 63 articles that were specific to ACE-I-AE, of which 46 were deemed appropriate for grading in the final focused review.

CONCLUSIONS

The primary focus for the treatment of ACE-I-AE is airway management. In the absence of high-quality evidence, no specific medication therapy is recommended for its treatment. If, however, the treating physician feels the patient's presentation is more typical of an acute allergic reaction or anaphylaxis, it may be appropriate to treat for those conditions. Any patient with suspected ACE-I-AE should immediately discontinue that medication.

ACE inhibitor-mediated angioedema

Angioedema (AE) occurring during ACE inhibitor therapy (ACEi-AE) is a rare complication involving between 0.1 and 0.7% of treated patients. AE can also complicate other therapeutic regimens that block the renin-angiotensin aldosterone system. Other drugs, such as immune suppressors, some type of antidiabetics or calcium antagonists, can increase the likelihood of ACEi-AE when associated to ACEi. There is a clear ethnic predisposition, since African-Americans or Hispanics show a higher prevalence of this condition compared to Caucasians. At least in African-Americans the genetic predisposition accounts for a general higher prevalence of AE, independently from the cause. People that experience ACEi-AE may have some recurrence when they are switched to an angiotensin-receptor blocker (ARB); however, epidemiological studies on large cohorts have shown that angiotensin receptor blockers (ARB) do not increase the likelihood of AE compared to other antihypertensives. Clinical manifestations consist of edema of face, lips, tongue, uvula and upper airways, requiring intubation or tracheotomy in severe cases. Attacks last for 48-72 h and require hospital admission in most cases. Intestinal involvement with sub-occlusive symptoms has also been reported. The pathogenesis of ACEi-AE depends mainly on a reduced catabolism and accumulation of bradykinin, which is normally metabolized by ACE. Genetic studies have shown that some single nucleotide polymorphisms at genes encoding relevant molecules for bradykinin metabolism and action may be involved in ACEi-AE, giving a basis for the ethnic predisposition. Treatment of ACEi-AE is still a matter of debate. Corticosteroids and antihistamines do not show efficacy. Some therapeutic attempts have shown some efficacy for fresh frozen plasma or C1 inhibitor concentrate infusion. Interventional studies with the specific bradykinin receptor antagonist icatibant have shown conflicting results; there might be a different ethnic predisposition to icatibant efficacy which has been proven in caucasian but not in black patients.

Evaluation and Management of Angioedema in the Emergency Department

Angioedema is defined by non-dependent, non-pitting edema that affects several different sites and is potentially life-threatening due to laryngeal edema. This narrative review provides emergency physicians with a focused overview of the evaluation and management of angioedema. Two primary forms include histamine-mediated and bradykinin-mediated angioedema. Histamine-mediated forms present similarly to anaphylaxis, while bradykinin-mediated angioedema presents with greater face and oropharyngeal involvement and higher risk of progression. Initial evaluation and management should focus on evaluation of the airway, followed by obtaining relevant historical features, including family history, medications, and prior episodes. Histamine-mediated angioedema should be treated with epinephrine intramuscularly, antihistaminergic medications, and steroids. These medications are not effective for bradykinin-mediated forms. Other medications include C1-INH protein replacement, kallikrein inhibitor, and bradykinin receptor antagonists. Evidence is controversial concerning the efficacy of these medications in an acute episode, and airway management is the most important intervention when indicated. Airway intervention may require fiberoptic or video laryngoscopy, with preparation for cricothyrotomy. Disposition is dependent on patient's airway and respiratory status, as well as the sites involved.

Treatment of Life-Threatening ACE-Inhibitor-Induced Angioedema

Incidence of angioedema associated with angiotensin-converting enzyme inhibitors (ACE-I) has been estimated at 0.1%-2.2% of patients receiving treatment. Despite the potential severity of this disease state, standardized treatment is lacking. Traditional pharmacotherapy options include medications that target inflammatory mediators and the angiotensin pathway. However, because ACE-I-induced angioedema is caused by accumulation of bradykinin, these medications fail to target the underlying pathophysiology. Recently, novel therapies that target the kallikrein-bradykinin pathway have been studied. These include icatibant, ecallantide, C1 esterase inhibitors, and fresh-frozen plasma. Recent randomized controlled trials exhibit contradictory results with the use of icatibant. This is a focused review on traditional and novel treatment strategies for ACE-I-induced angioedema.

Efficacy of Treatment of Non-hereditary Angioedema

Non-hereditary angioedema (AE) with normal C1 esterase inhibitor (C1INH) can be presumably bradykinin- or mast cell-mediated, or of unknown cause. In this systematic review, we searched PubMed, EMBASE, and Scopus to provide an overview of the efficacy of different treatment options for the abovementioned subtypes of refractory non-hereditary AE with or without wheals and with normal C1INH. After study selection and risk of bias assessment, 61 articles were included for data extraction and analysis. Therapies were described for angiotensin-converting enzyme inhibitor-induced AE (ACEi-AE), for idiopathic AE, and for AE with wheals. Described treatments consisted of ecallantide, icatibant, C1INH, fresh frozen plasma (FFP), tranexamic acid (TA), and omalizumab. Additionally, individual studies for anti-vitamin K, progestin, and methotrexate were found. Safety information was available in 26 articles. Most therapies were used off-label and in few patients. There is a need for additional studies with a high level of evidence. In conclusion, in acute attacks of ACEi-AE and idiopathic AE, treatment with icatibant, C1INH, TA, and FFP often leads to symptom relief within 2 h, with limited side effects. For prophylactic treatment of idiopathic AE and AE with wheals, omalizumab, TA, and C1INH were effective and safe in the majority of patients.

Diagnosis and treatment of upper airway oedema caused by acute angio-oedema in the emergency department: a French consensus statement

Angio-oedema is a transitory, localized, noninflammatory oedema of subcutaneous tissue or mucous. When the oedema affects the mouth, lips, tongue or larynx, it can result in fatal asphyxiation in the absence of specific treatment. Oedema secondary to plasma extravasation is usually mediated by either histamine or bradykinin. As laboratory tests are not available in an emergency setting, the implicated mediator cannot be readily determined. The challenge for the emergency physician is to determine the aetiological type, evaluate severity and initiate adapted treatment by means of a structured approach. A team of experts from the French Reference Centre for Angio-oedema reached a consensus for recommendations for the diagnostic and therapeutic strategy to be adopted by emergency departments faced with angio-oedema of the upper airways in adults. The experts defined 11 important questions. Responses were rated using a two-round Delphi methodology. The 11 recommendations were related to triage on admission, a step-by-step diagnostic protocol, definition of attack severity, discouragement of instrumental examination, prioritization of treatment for severe attacks according to clinical signs and anticipation of access to specific treatments by the hospital. Angio-oedema of the upper airways can be fatal and requires anticipation by the emergency department. A search for the aetiology, an evaluation of clinical symptoms and the availability of the treatments are challenges justifying these recommendations.

Angioedema Phenotypes: Disease Expression and Classification

Due to marked heterogeneity of clinical presentations, comprehensive knowledge of angioedema phenotypes is crucial for correct diagnosis and choosing the appropriate therapeutic approach. One of the ways to a meaningful clinical distinction can be made between forms of angioedema occurring "with or without wheals." Angioedema with wheals (rash) is a hallmark of urticaria, either acute or chronic, spontaneous or inducible. Angioedema without wheals may still be manifested in about 10 % of patients with urticaria, but it may also occur as a separate entity. Several classifications of angioedema as part of urticaria were published over time, while a latest one, released in 2014 (HAWK group consensus, see below), provided a classification of all forms of "angioedema without wheals" distinct from urticaria, which will be the focus of the present review. At this time, the HAWK consensus classification is the best in terms of covering the pathophysiology, mediators involved, angioedema triggers, and clinical expression. According to this classification, three types of hereditary angioedema (genetic C1-INH deficiency, normal C1-INH with factor XII mutations, and unknown origin) and four types of acquired angioedema (C1-INH deficiency, related to ACE inhibitors intake, idiopathic histaminergic, and idiopathic non-histaminergic) are presented. We will review the distinctive clinical features of each phenotype in details.

Pharmacologic management of angioedema induced by angiotensin-converting enzyme inhibitors

Purpose

The published evidence on pharmacologic approaches to the management of angiotensin-converting enzyme inhibitor (ACEI)–induced angioedema is reviewed.

Summary

Angioedema is a serious, potentially life-threatening adverse effect of ACEI use. Although the underlying mechanism is not fully understood, excess bradykinin produced through a complex interplay between the kallikrein-kinin and renin-angiotensin-aldosterone systems is thought to play a major role. The nonallergic nature of the reaction renders traditional therapies (corticosteroids and antihistamines) ineffective because those agents do not modify the proposed pathophysiology. Fresh frozen plasma (FFP) provides kinase II, a protein that breaks down bradykinin. Case reports support FFP as a treatment for ACEI-induced angioedema, but no formal evaluations have been completed to date. Both ecallantide and complement 1 esterase (C1) inhibitor concentrate reduce bradykinin production through upstream inhibition of kallikrein. C1 inhibitor concentrate has been used successfully to manage ACEI-induced angioedema in a few reported cases, but robust supportive studies are lacking. Conversely, ecallantide has been evaluated in multiple randomized trials but has not been shown to offer advantages over traditional therapies. The use of icatibant, a direct antagonist of bradykinin B2 receptors, was reported to be beneficial in several case reports and in a small Phase II study, safely and rapidly reducing symptoms of ACEI-induced angioedema. An ongoing Phase III trial (NCT01919801) will better define the role of icatibant in the management of ACEI-induced angioedema.

Conclusion

FFP, C1 inhibitor, and icatibant appear to be safe and effective therapeutic options for the management of ACEI-induced angioedema, whereas it appears ecallantide should be avoided.

Off-Label Use of Agents for Management of Serious or Life-threatening Angiotensin Converting Enzyme Inhibitor–Induced Angioedema

Objective: To evaluate the place in therapy of fresh frozen plasma (FFP), C1 esterase concentrate (C1-INH), ecallantide, and icatibant in the management of angiotensin-converting enzyme inhibitor–induced angioedema (ACEI-IA). Data Sources: A literature search was performed using PubMed (1946 through August 2015) and Embase (<1966 through August 2015). References from identified articles were reviewed. Study Selection and Data Extraction: Consensus papers, practice guidelines, case reports/series, clinical trials, and meeting abstracts published in English and involving humans were included. Data Synthesis: No medications are currently Food and Drug Administration–approved for managing ACEI-IA. Emerging evidence suggests that FFP and medications approved for management of acute attacks of hereditary angioedema, another bradykinin-mediated event, may be effective for use in ACEI-IA. Positive efficacy results were reported with FFP and C1-INH while mixed results have been seen with ecallantide. Off-label icatibant has the most evidence supporting its use in ACEI-IA with rapid symptom resolution (10 minutes to 6 hours) and avoidance of intubation and tracheotomy in several cases. These agents were well-tolerated in ACEI-IA. Conclusion: ACEI-IA is typically a self-limiting event. First-line therapies include ACEI discontinuation, observation, and supportive medications (eg, corticosteroids, antihistamines, and epinephrine). Symptom progression can be life-threatening and may require interventions such as tracheotomy and intubation. Off-label use of FFP and medications approved for hereditary angioedema have resulted in rapid resolution of symptoms and avoidance of intubation. Among these agents, icatibant has the most supporting evidence and has been incorporated into practice guidelines and algorithms as a second-line agent for serious life-threatening ACE-IA.