Do beta-blockers really enhance the risk of anaphylaxis during immunotherapy?

Systemic Allergic Reactions and Anaphylaxis Associated with Allergen Immunotherapy

Subcutaneous allergen immunotherapy (SCIT) is a proven treatment of allergic rhinitis, asthma, atopic dermatitis, and prevention of Hymenoptera venom anaphylaxis. The known benefit of SCIT, however, must be considered in each patient relative to the potential risks of systemic allergic reactions (SRs). A mean of 1 SR per 1000 injection visits (0.1%) was estimated to occur between 2008 and 2018. Life-threatening anaphylactic events are estimated to occur in 1/160,000 injection visits. The factors that contribute to SRs and fatal reactions (FRs) are reviewed. Risk management strategies are proposed to prevent and decrease future SCIT associated with SRs, anaphylaxis, and FR.

β-Blockers and angiotensin-converting enzyme inhibitors with sublingual immunotherapy: are risks related to individual product safety profile?

PURPOSE OF REVIEW

The objective of this article is to review the available literature regarding the risks associated with sublingual immunotherapy and angiotensin-converting enzyme (ACE) inhibitors or β-blocker use. It also evaluates for any differences in these risks among the available sublingual immunotherapy (SLIT) tablets.

RECENT FINDINGS

A literature search was conducted in PubMed to identify peer-reviewed articles using the following keywords: anaphylaxis, ACE inhibitor, β-blocker, and sublingual immunotherapy. Minimal data exist regarding their safety of SLIT in patients concomitantly taking ACE inhibitors or β-blockers. The adverse reaction rates seem similar between SLIT products.

SUMMARY

A risk-versus-benefit discussion should be communicated with the patient taking a β-blocker before beginning SLIT but automatic denial of SLIT to these patients is not warranted.

Risk for Anaphylactic Reaction from Cardiac Catheterization in Patients Receiving β-Adrenergic Blockers or Angiotensin-Converting Enzyme-Inhibitors

BACKGROUND

β-Adrenergic blockers (BBs) have been associated with increased risk for severe anaphylactic reaction (AR) from contrast media; however, this was shown with intravenous contrast media, before widespread use of low osmolar contrast media, angiotensin-converting enzyme-inhibitors (ACE-Is), and cardioselective BBs.

OBJECTIVE

To assess the risk for AR during cardiac catheterization (CC) associated with BB or ACE-I exposure.

METHODS

Patients who experienced adverse reactions during CC from January 2004 to December 2013 were identified; 1 to 2 matched controls were assigned for each case. We analyzed AR rates in association with demographic variables, medication exposures (BBs, ACE-Is, angiotensin-receptor blockers, aspirin), and comorbidities: cardiovascular disorders, asthma, and atopy.

RESULTS

We analyzed 71,782 CCs. Of these, severe 70 reactors were identified-46 (0.06%) fulfilled AR criteria. There were 35 cases of mild to moderate AR and 11 cases of severe AR (0.015%). There were no significant differences in age (61.3% vs 61.5%), sex (63% vs 64% males), cardiovascular disorder rate (78% vs 93%), and exposure to BBs (46% vs 51%; cardioselective: 77% vs 80%) and ACE-Is (37.0% vs 37.2%) in cases versus controls. Via multivariate logistic regression, BB exposure was not associated with greater AR frequency (P = .35) or severity (P = .40). Neither cardioselective BBs (P = 0.2) nor noncardioselective BBs (P = .5) influenced AR severity. ACE-Is had no effect on AR frequency (P = .35) or severity (P = .14). Lower AR frequency was associated with cardiovascular disorder (P = .01).

CONCLUSIONS

In this case-control study, severe AR was rarely observed. Exposure to BBs or ACE-Is did not significantly influence AR frequency or severity; however, most BBs were cardioselective. Our findings imply that cardioselective BB or ACE-I suspension is not warranted in association with CC.

Relationship Between Anaphylaxis and Use of Beta-Blockers and Angiotensin-Converting Enzyme Inhibitors: A Systematic Review and Meta-Analysis of Observational Studies

BACKGROUND

Beta-blockers (BBs) and angiotensin-converting enzyme inhibitors (ACEIs) have been associated with an increased risk and severity of anaphylaxis. However, the evidence supporting these findings is contradictory.

OBJECTIVE

We carried out a systematic review and meta-analysis of studies that assess the influence of BBs and ACEIs on anaphylaxis.

METHODS

We searched PubMed/MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews, and the Web of Science for relevant observational studies. We searched for studies where the presence and severity of anaphylaxis were compared between patients taking BBs, ACEIs, both types of drug, or neither type of drug. We performed a meta-analysis using a random-effects model.

RESULTS

A total of 21 studies met the study criteria. Of these, 15 assessed the severity and 9 the incidence of anaphylaxis. The studies brought together 22,313 anaphylaxis episodes for the severity studies and 18,101 anaphylaxis episodes for the studies of new cases of anaphylaxis. BBs and ACEIs increased the severity of anaphylaxis (BBs, odds ratio [OR] 2.19, 95% confidence interval [CI] 1.25-3.84; ACEIs, OR 1.56, 95% CI 1.12-2.16), but not the presence of new cases of anaphylaxis (BBs, OR 1.40, 95% CI 0.91-2.14; ACEIs, OR 1.38, 95% CI 0.39-4.86). It was not possible to perform an analysis adjusted for cardiovascular diseases, because only 1 study each for BBs and ACEIs, respectively, had adjusted data.

CONCLUSIONS

The quality of evidence showing that the use of BBs and ACEI increases the severity of anaphylaxis is low owing to differences in the control of confounders arising from the concomitant presence of cardiovascular diseases.

Evidence in immunotherapy for paediatric respiratory allergy: Advances and recommendations

Allergic respiratory diseases are major health problems in paediatric population due their high level of prevalence and chronicity, and to their relevance in the costs and quality of life. One of the most important risk factors for the development of airway diseases in children and adolescents is atopy. The mainstays for the treatment of these diseases are avoiding allergens, controlling symptoms, and preventing them through sustained desensitization by allergen immunotherapy (AIT). AIT is a treatment option that consists in the administration of increasing amounts of allergens to modify the biological response to them, inducing long-term tolerance even after treatment has ended. This treatment approach has shown to decrease symptoms and improve quality of life, becoming cost effective for a large number of patients. In addition, it is considered the only treatment that can influence the natural course of the disease by targeting the cause of the allergic inflammatory response. The aim of this publication is to reflect the advances of AIT in the diagnosis and treatment of allergic respiratory diseases in children and adolescents reviewing articles published since 2000, establishing evidence categories to support the strength of the recommendations based on evidence. The first part of the article covers the prerequisite issues to understand how AIT is effective, such as the correct etiologic and clinical diagnosis of allergic respiratory diseases. Following this, the article outlines the advancements in understanding the mechanisms by which AIT achieve immune tolerance to allergens. Administration routes, treatment regimens, dose and duration, efficacy, safety, and factors associated with adherence are also reviewed. Finally, the article reviews future advances in the research of AIT.

Choosing wisely: practical considerations on treatment efficacy and safety of asthma in the elderly

The prevalence of asthma in the most advanced ages is similar to that of younger ages. However, the concept that older individuals may suffer from allergic asthma has been largely denied in the past, and a common belief attributes to asthma the definition of "rare" disease. Indeed, asthma in the elderly is often underdiagnosed or diagnosed as COPD, thus leading to undertreatment of improper treatment. This is also due to the heterogeneity of clinical and functional presentations of geriatric asthma, including the partial loss of reversibility and the lower occurrence of the allergic component in this age range. The older asthmatic patients are also characterized the coexistence of comorbid conditions that, in conjunction with age-associated structural and functional changes of the lung, may contribute to complicate the management of asthma. The current review addresses the main issues related to the management of allergic asthma in the geriatric age. In particular, the paper aims at revising current pharmacological and non pharmacological treatments for allergic asthmatics of advanced ages, primarily focusing on their safety and efficacy, although most behaviors are an arbitrary extrapolation of what has been tested in young ages. In fact, age has always represented an exclusion criterion for eligibility to clinical trials. Experimental studies and real life observations specifically testing the efficacy and safety of therapeutic approaches in allergic asthma in the elderly are urgently needed.

Inmunoterapia con alérgenos, ¿cuándo y por qué?

La inmunoterapia específica con alérgenos es el único tratamiento que modifica el curso natural de algunas enfermedades alérgicas como asma, rinitis, conjuntivitis, dermatitis atópica y alergia al veneno de himenópteros. Sin embargo, aún existe cierta controversia respecto a su seguridad y su utilidad clínica. En el presente artículo se presenta una revisión de los mecanismos moleculares, las indicaciones y contraindicaciones de dicha inmunoterapia, y se evalúan su seguridad y eficacia en cada una de estas enfermedades mediante casos ilustrativos y una breve revisión del tema.

Aspirin hypersensitivity and desensitization protocols: implications for cardiac patients

Aspirin or acetylsalicylic acid is an important therapy for many cardiology patients but hypersensitivity to this drug affects around 1% of the population and intolerance may affect up to 20%. While alternative medications to aspirin are available, in many cases there is a compelling need for aspirin therapy. In these patients, aspirin desensitization may be considered. However, this is a complex issue with a lack of international standardization. This article reviews the available evidence for aspirin desensitization and provides practical advice for the management of these patients.

Risk factors for severe anaphylaxis in patients receiving anaphylaxis treatment in US emergency departments and hospitals

BACKGROUND

Although reported risk factors for severe anaphylaxis include older age, presence of comorbid medical conditions, and concomitant medications, previous studies have used varying definitions for anaphylaxis and heterogeneous methodology.

OBJECTIVE

To describe risk factors for severe anaphylaxis among US patients treated in emergency departments (EDs) or hospitals for anaphylaxis.

METHODS

Individuals with an ED visit/hospitalization for anaphylaxis were identified from 2 MarketScan Research Databases using an expanded International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code algorithm. Eligibility for the current study required continuous medical and prescription coverage for at least 1 year before and after the index date. Severe anaphylaxis was defined as a reaction requiring hospital admission.

RESULTS

Among 11,972 individuals, 2,622 (22%) had severe anaphylaxis. Unadjusted analysis showed that severe anaphylaxis was associated with older age and higher comorbidity burden. These patients were also less likely to have filled an epinephrine autoinjector (EAI) prescription or visited an allergist/immunologist, but more likely to have had an ED visit/hospitalization (any cause). On multivariable analysis, filling an EAI prescription (odds ratio [OR], 0.64; 95% CI, 0.53-0.78) or visiting an allergist/immunologist (OR, 0.78; 95% CI, 0.63-0.95) before the index event was associated with a lower risk of severe anaphylaxis, while any previous ED visit (OR, 1.18; 95% CI, 1.07-1.30) or hospitalization (OR, 1.55; 95% CI, 1.36-1.75) was associated with a higher risk of severe anaphylaxis.

CONCLUSIONS

In this large cohort with an ED visit or hospitalization for anaphylaxis, 22% had severe anaphylaxis. Pre-index preventive anaphylaxis care (ie, EAI prescription fill and allergist/immunologist visit) was associated with a significantly lower risk, supporting the benefits of preventive anaphylaxis care in real-world practice.

Systemic reactions associated with subcutaneous allergen immunotherapy: timing and risk assessment

BACKGROUND

Subcutaneous allergen immunotherapy (SCIT) is associated with risk of systemic reaction. Although risk factors have been identified, the incidence of immunotherapy-related systemic reactions has not changed in recent years.

OBJECTIVES

To examine patterns of systemic reaction and determine whether risk of systemic reaction from SCIT is associated with patterns of response to skin tests to inhalant allergens recorded before receiving SCIT.

METHODS

We carried out a retrospective review from January 2001 to December 2007. Patterns of systemic reaction from immunotherapy were examined. Cases were matched with controls by age (±10 years), sex, and time of injection (±1 week) to determine whether a pattern of more than 33% 3+ and 4+ skin test responses is associated with elevated risk for systemic reaction.

RESULTS

Rate of systemic reaction from SCIT was 0.28% (46/16,375) per injection visit. Twenty patients had 46 systemic reactions. All severe reactions occurred within 30 minutes. The estimated odds of systemic reaction were almost 6 times higher for patients with more than 33% 3 to 4+ positive skin tests (OR = 5.83; 95%CI: 1.23-27.59, P = .026). For each additional 4+ skin test, the estimated odds for systemic reaction increased by 17% (P = .020).

CONCLUSIONS

A small number of patients receiving SCIT account for a large proportion of systemic reactions. Skin test patterns demonstrating a greater number of larger skin tests responses to inhalant skin testing are associated with significantly elevated risk for systemic reaction in patients receiving SCIT.

Predictors of severe systemic anaphylactic reactions in patients with Hymenoptera venom allergy: importance of baseline serum tryptase-a study of the European Academy of Allergology and Clinical Immunology Interest Group on Insect Venom Hypersensitivity

BACKGROUND

Severe anaphylaxis to honeybee or vespid stings is associated with a variety of risk factors, which are poorly defined.

OBJECTIVE

Our aim was to evaluate the association of baseline serum tryptase concentrations and other variables routinely recorded during patient evaluation with the frequency of past severe anaphylaxis after a field sting.

METHODS

In this observational multicenter study, we enrolled 962 patients with established bee or vespid venom allergy who had a systemic reaction after a field sting. Data were collected on tryptase concentration, age, sex, culprit insect, cardiovascular medication, and the number of preceding minor systemic reactions before the index field sting. A severe reaction was defined as anaphylactic shock, loss of consciousness, or cardiopulmonary arrest. The index sting was defined as the hitherto first, most severe systemic field-sting reaction. Relative rates were calculated with generalized additive models.

RESULTS

Two hundred six (21.4%) patients had a severe anaphylactic reaction after a field sting. The frequency of this event increased significantly with higher tryptase concentrations (nonlinear association). Other factors significantly associated with severe reactions after a field sting were vespid venom allergy, older age, male sex, angiotensin-converting enzyme inhibitor medication, and 1 or more preceding field stings with a less severe systemic reaction.

CONCLUSION

In patients with honeybee or vespid venom allergy, baseline serum tryptase concentrations are associated with the risk for severe anaphylactic reactions. Preventive measures should include substitution of angiotensin-converting enzyme inhibitors.

Anaphylaxis: Recent advances in assessment and treatment

The incidence rate of anaphylaxis is increasing, particularly during the first 2 decades of life. Common triggers include foods, medications, and insect stings. Clinical diagnosis is based on a meticulous history of an exposure or event preceding characteristic symptoms and signs, sometimes but not always supported by a laboratory test such as an elevated serum total tryptase level. Physician-initiated investigation of patients with anaphylaxis whose symptoms and signs are atypical sometimes leads to important insights into previously unrecognized triggers and mechanisms. In idiopathic anaphylaxis, in which no trigger can be confirmed by means of skin testing or measurement of specific IgE, the possibility of mastocytosis or a clonal mast cell disorder must be considered in addition to the possibility of a previously unrecognized trigger. Long-term risk reduction in patients with anaphylaxis focuses on optimal management of relevant comorbidities such as asthma and other respiratory diseases, cardiovascular disease, and mastocytosis or a clonal mast cell disorder; avoidance of the relevant confirmed allergen trigger; and relevant immunomodulation such as medication desensitization, venom immunotherapy, and possibly in the future, immunotherapy with food. Emergency preparedness for recurrence of anaphylaxis in community settings includes having epinephrine (adrenaline) autoinjectors available, knowing when and how to use them, and having a written, personalized anaphylaxis emergency action plan and up-to-date medical identification. Randomized controlled trials of the pharmacologic interventions used in an acute anaphylaxis episode are needed.