Anaphylaxis is an acute and potentially lethal multisystem allergic reaction. Most consensus guidelines for the past 30 years have held that epinephrine is the drug of choice and the first drug that should be administered in acute anaphylaxis. Some state that properly administered epinephrine has no absolute contraindication in this clinical setting. A committee of anaphylaxis experts assembled by the World Allergy Organization has examined the evidence from the medical literature concerning the appropriate use of epinephrine for anaphylaxis. The committee strongly believes that epinephrine is currently underused and often dosed suboptimally to treat anaphylaxis, is underprescribed for potential future self-administration, that most of the reasons proposed to withhold its clinical use are flawed, and that the therapeutic benefits of epinephrine exceed the risk when given in appropriate intramuscular doses.Key Words: anaphylaxis, epinephrine, management, prevention (WAO Journal 2008;S18YS26) E pinephrine is the treatment of choice and the first drug administered for acute anaphylaxis, as confirmed internationally by most consensus anaphylaxis guidelines published in the English language over the past 30 years.
1Y17Therapeutic recommendations for epinephrine use in anaphylaxis are largely based on clinical pharmacology studies, clinical observation, and animal models.Anaphylaxis often occurs outside of a medical setting, for example, after food ingestion or an insect sting, and the onset may be sudden and without warning. Severity varies from episode to episode even with an identical stimulus in the same patient. Recognition and diagnosis of anaphylaxis is sometimes difficult for health care professionals and for individuals without medical training.
18Few controlled clinical trials, and no placebo-controlled trials, have been performed in anaphylaxis because of the nature of the disease. 19 Randomization to a nonepinephrine treatment would be unethical because of the preponderance of data showing that expeditious treatment with epinephrine is optimal, if not critical, for survival in many instances. 20Y25 The following discussion reviews current evidence for the use of epinephrine in anaphylaxis.
DEFINITIONThe traditional nomenclature for anaphylaxis reserves the term anaphylactic for immunoglobulin E (IgE)Ydependent reactions and the term anaphylactoid for IgE-independent events, which are clinically indistinguishable. The World Allergy Organization, a worldwide federation of national and regional allergy and clinical immunology societies and organizations dedicated to raising awareness and advancing excellence in clinical care, education, research, and training in allergy and clinical immunology, recommends that this terminology be replaced with immunologic (IgE-mediated and non-IgEYmediated [eg, IgG and immune complex complementYmediated]) and nonimmunologic anaphylaxis. 26 Therefore, in this article, the term anaphylaxis refers to both immunologic and nonimmunologic anaphylaxis.
METHODSA literature...