Content Update: TXA for ACE-Inhibitor- induced angioedema April 2020
Tranexamic acid (TXA) is a readily available, safe, and cost-effective therapy for acute trauma and bleeding. It has been used in ACE-Inhibitor-induced angioedema and idiopathic angioedema, and is recommended by some authors (1). The mechanism of action is unknown, but it may prevent the plasmin-dependent formation of bradykinin (2) No randomized controlled trials are available (3), but weak evidence from observational studies suggests that TXA can be an alternative strategy for ACEI or idiopathic angioedema. The effectiveness of TXA in hereditary Cl inhibitor-deficiency angioedema is not as compelling as for ACEI angioedema (4,5) For a potential airway emergency, the dose is 1 gram IV. See Table 14-6.
1) van den Elzen M et al 'Efficacy of treatment of non-hereditary angioedema.' Clin Rev Allergy Immunol 2018:54 (3):412-431 PMID 276720782)
2)Sheffer AL et al 'Tranexamic acid therapy in hereditary angioneurotic edema' NEnglJMed 1972; 287:452-454
3) Beauchene C et al 'TXA as first line emergency treatment for episodes of bradykinin-mediated angioedema induced by ACE inhibitors' Rev Med Interne 2018; 39(10):772-776 Doi 10.1016/j.revmed.2018.04.014
4) Zanichelli A et al 'Standard care impact on angioedema because of hereditary C1 Inhibitor Deficiency: a 21-month prospective study in a sohort of 103 patients' Allergy 2011; 66:192-96 PMID 21039598
5) Horiuchi T et al 'The use of tranexamic acid for on-demand and prophylactic treatment of hereditary angioedema-A Systematic Review' J CutanImmunolAllergy. 2018; 1:126-138
Anaphylaxis is a serious allergic reaction, with a rapid onset; it may cause death and requires emergent diagnosis and treatment. Consensus clinical criteria provide consistency for diagnosis (Table 14-1).1–3
TABLE 14-1Clinical Criteria for Anaphylaxis |Favorite Table|Download (.pdf) TABLE 14-1Clinical Criteria for Anaphylaxis
Urticaria, generalized itching or flushing, or edema of lips, tongue, uvula, or skin developing over minutes to hours and associated with at least 1 of the following:
Respiratory distress or hypoxiaor
Hypotension or cardiovascular collapseor
Associated symptoms of organ dysfunction (e.g., hypotonia, syncope, incontinence)
Two or more signs or symptoms that occur minutes to hours after allergen exposure:
Skin and/or mucosal involvement
Hypotension or associated symptoms
Persistent GI cramps or vomiting
Consider anaphylaxis when patients are exposed to a known allergen and develop hypotension
The terms anaphylactic and anaphylactoid were previously applied to immunoglobulin E (IgE)-dependent and IgE-independent events, respectively. Because the final pathway in both events is identical, anaphylaxis is the term now used to refer to both.4 Hypersensitivity is an inappropriate immune response to generally harmless antigens, representing a continuum from minor to severe manifestations. Anaphylaxis represents the most dramatic and severe form of immediate hypersensitivity.
Foods, medications, insect stings, and allergen immunotherapy injections are the most common provoking factors for anaphylaxis, but any agent capable of producing a sudden degranulation of mast cells or basophils can induce anaphylaxis (Table 14-2)....