Icatibant in angiotensin-converting enzyme (ACE) inhibitor-associated angioedema

Over diagnosis of bradykinin angioedema in patients treated with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers

Background

Bradykinin angioedemas are a potentially serious side effect of angiotensin-converting enzyme inhibitors (ACEI) and more controversially of angiotensin II receptor blockers (ARB). Their challenging diagnosis is based on the absence of any recurrence after more than 6 months of drug discontinuation; otherwise mast-cell driven angioedemas as a differential diagnosis must be considered.

Objective

The aim of this study was to determine the prevalence of recurrent angioedema in patients referred for ACEI/ARB-induced bradykinin angioedema, after more than 6 months of drug discontinuation.

Methods

We included ACEI/ARB-treated patients referred for angioedema(s) without hives and unresponsive to antihistamines, after they discontinued ACEI/ARB for at least 6 months. Any C1-inhibitor deficiency was excluded. The primary endpoint was the prevalence of patients with recurrent angioedema after more than 6 months of drug discontinuation and/or developing hives during follow-up. The secondary endpoint was the identification of epidemiological factors associated with any final diagnosis.

Results

Thirty-eight of 93 patients (41%) with a suspicion of ACEI/ARB-induced bradykinin angioedema still had recurrent angioedema (n = 27) or developed hives (n = 2) or both (n = 9) after 6 months of drug discontinuation. Good response to icatibant and facial but not oral localization were predictive for the final diagnosis of ACEI/ARB-induced bradykinin angioedema and mast-cell driven angioedema, respectively.

Conclusion

In patients referred for acquired angioedema without wheals occurring during ACEI/ARB therapy, 59% finally had a diagnosis of ACEI/ARB-induced bradykinin angioedema whereas 41% were rather diagnosed with mast-cell driven angioedema. The overdiagnosis of ACEI/ARB-induced bradykinin angioedema may deteriorate the management of severe cardiovascular conditions.

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.

Pediatric Angioedema without Wheals: How to Guide the Diagnosis

Angioedema (AE) is a vascular reaction of subcutaneous and submucosal tissues that identifies various clinical pictures and often is associated with wheals. AE without wheals (AEwW) is infrequent. The ability to distinguish between AEwW mediated by mast cells and bradykinin-mediated or leukotriene-mediated pathways is often crucial for a correct diagnostic-therapeutic and follow-up approach. AEwW can be hereditary or acquired. Factors typically correlated with hereditary angioedema (HAE) are a recurrence of episodes, familiarity, association with abdominal pain, onset after trauma or invasive procedures, refractoriness to antiallergic therapy, and lack of pruritus. The acquired forms of AE can present a definite cause based on the anamnesis and diagnostic tests. Still, they can also have an undetermined cause (idiopathic AE), distinguished according to the response to antihistamine in histamine-mediated and non-histamine-mediated forms. Usually, in childhood, AE responds to antihistamines. If AEwW is not responsive to commonly used treatments, it is necessary to consider alternative diagnoses, even for pediatric patients. In general, a correct diagnostic classification allows, in most cases, optimal management of the patient with the prescription of appropriate therapy and the planning of an adequate follow-up.

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.

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.

Angioedema Masqueraders

Angioedema is a common reason for referral to immunology and allergy specialists. Not all cases are in fact angioedema. There are many conditions that may mimic its appearance, resulting in misdiagnosis. This may happen when a clinician is unfamiliar with conditions resembling angioedema or when there is a low index of clinical suspicion. In this article, we explore a list of differential diagnoses based on body parts, including the lips, the limbs, periorbital tissues, the face, epiglottis and uvula, as well as the genitalia, that may pose as a masquerader even to an experienced eye.

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.

Icatibant for Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema in Intubated Patients: Case Series and Literature Review

Purpose

A case series of icatibant use in intubated patients with angiotensin-converting enzyme inhibitor- (ACEI-) induced angioedema is presented along with a relevant literature review and recommendations for utilization.

Summary

Three intubated patients admitted to the intensive care unit for ACEI-induced angioedema were treated with icatibant. A literature search identified one controlled study and four case reports describing the use of icatibant in intubated ACEI-induced angioedema patients.

Conclusion

Icatibant administration in intubated patients may be beneficial in decreasing time to extubation and length of intensive care unit stay. In the three cases described, icatibant administration did not appear to elicit a response in intubated patients, which has been described in previous case reports. For clinicians considering icatibant in the treatment of ACEI-induced angioedema, earlier administration upon arrival to the ED or immediately upon arriving to the intensive care unit is strongly advised. The suggested benefit of icatibant in intubated ACEI-induced angioedema patients should be verified by randomized clinical trials and cost-benefit analyses should be performed at individual institutions.

Angioedema: Clinical Presentations and Pharmacological Management

Angioedema (AE) is a unique clinical presentation of an unchecked release of bradykinin. The origin of this clinical presentation can be either genetic or acquired. The outcome within the patient is subcutaneous swelling of the lower layers of the epidermis. Symptoms are most often localized to the upper airway or the gastrointestinal tract. A typical course resolves in 5 to 7 days, but in some patients, the clinical manifestations exist up to 6 weeks. Hereditary AE is rare and genetically linked, and typically, the patient has episodes for many years before diagnosis. Episodes of acquired AE may be drug induced, triggered by a specific allergen, or idiopathic. Angioedema can elicit the need for critical care interventions, for advanced airway management, or unnecessary abdominal surgery. The treatment for these patients is evolving as new pharmacological agents are developed. This article addresses subtypes of AE, triggers, pharmacology, and information for interdisciplinary team planning of individualized case management.

C1 Esterase Inhibitor (Berinert) for ACE Inhibitor-Induced Angioedema: Two Case Reports

OBJECTIVE

To describe 2 cases of angiotensin-converting enzyme inhibitor (ACEI)-induced angioedema treated with C1 esterase inhibitor (human) [Berinert].

SUMMARY

Case 1 is a 60-year-old Caucasian male with angioedema from lisinopril. He was initially treated with a conventional regimen of an antihistamine, methylprednisolone, epinephrine, and fresh frozen plasma. When symptoms did not resolve, intravenous C1 peptide esterase inhibitor (C1INH) was administered, with clinical improvement. Four hours later, symptoms returned and the patient underwent emergency tracheostomy. Case 2 is a 64-year-old Caucasian male who presented with angioedema due to enalapril. In the emergency department, he received conventional treatment. Endotracheal tube placement was unsuccessful. While the patient was undergoing intubation in the operating room, intravenous C1INH was administered resulting in quick improvement of symptoms.

DISCUSSION

Angioedema from ACEI occurs at an incidence of 0.7%. Conventional treatment may be of limited benefit due to the mechanism of the reaction. C1INHs, which are indicated for hereditary angioedema, have been utilized in treating ACEI-induced angioedema. According to the Naranjo algorithm scale, the patient in case 1 experienced angioedema that is probably related to lisinopril. C1INH was administered intravenously when symptoms progressed, despite conventional treatment. In case 2, the patient experienced angioedema, which is possibly related to enalapril, and was treated with C1INH.

CONCLUSION

C1INH (human) was a successful addition to the traditional management of 2 patients with angioedema due to ACEI.

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.