Medline ® Abstracts for References 11,15,77
of 'Anaphylaxis: Emergency treatment'
H1-antihistamines for the treatment of anaphylaxis: Cochrane systematic review.
Sheikh A, Ten Broek V, Brown SG, Simons FE
BACKGROUND: Anaphylaxis is an acute systemic allergic reaction, which can be life-threatening. H(1)-antihistamines are commonly used as an adjuvant therapy in the treatment of anaphylaxis. We sought to assess the benefits and harm of H(1)-antihistamines in the treatment of anaphylaxis.
METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library); MEDLINE (1966 to June 2006); EMBASE (1966 to June 2006); CINAHL (1982 to June 2006) and ISI Web of Science (1945 to July 2006). We also contacted pharmaceutical companies and international experts in anaphylaxis in an attempt to locate unpublished material. Randomized and quasi-randomized-controlled trials comparing H(1)-antihistamines with placebo or no intervention were eligible for inclusion. Two authors independently assessed articles for inclusion.
RESULTS: We found no studies that satisfied the inclusion criteria.
CONCLUSIONS: Based on this review, we are unable to make any recommendations for clinical practice. Randomized-controlled trials are needed, although these are likely to prove challenging to design and execute.
Division of Community Health Sciences: GP Section, University of Edinburgh, Edinburgh, UK.
Pharmacologic treatment of anaphylaxis: can the evidence base be strengthened?
Curr Opin Allergy Clin Immunol. 2010;10(4):384.
PURPOSE OF REVIEW: To evaluate the evidence base for the pharmacologic treatment of anaphylaxis.
RECENT FINDINGS: In this review, we focus on four classes of medications (the alpha/beta-agonist epinephrine (adrenaline), H1-antihistamines, H2-antihistamines, and glucocorticoids) that are used in healthcare settings for the initial treatment of anaphylaxis. Epinephrine and many H1-antihistamines and glucocorticoids were introduced before the era of randomized controlled trials and before the era of evidence-based medicine. In anaphylaxis, no randomized controlled trials that are free from methodological problems and meet current standards have been performed with these medications, or with H2-antihistamines. The evidence base for epinephrine injection is stronger than the evidence base for use of other medications in anaphylaxis. Guidelines unanimously recommend prompt injection of epinephrine as the life-saving first-line medication in anaphylaxis; however, they differ in their recommendations for H1-antihistamines, H2-antihistamines, and glucocorticoids. Epinephrine is the only medication that is universally available for anaphylaxis treatment in healthcare settings worldwide. Paradoxically, it is underused in anaphylaxis treatment.
SUMMARY: For ethical reasons, there should never be a placebo-controlled trial of epinephrine in anaphylaxis. We discuss why the possibility of conducting randomized placebo-controlled trials with H1-antihistamines, H2-antihistamines, and particularly with glucocorticoids in anaphylaxis should be considered in order to improve the evidence base for treatment and guide clinical decision-making. We also describe the precautions that will be needed if randomized controlled trials are conducted in anaphylaxis.
Department of Pediatrics&Child Health, Department of Immunology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada. firstname.lastname@example.org
Histamine and H1-antihistamines: celebrating a century of progress.
Simons FE, Simons KJ
J Allergy Clin Immunol. 2011;128(6):1139.
In this review we celebrate a century of progress since the initial description of the physiologic and pathologic roles of histamine and 70 years of progress since the introduction of H(1)-antihistamines for clinical use. We discuss histamine and clinically relevant information about the molecular mechanisms of action of H(1)-antihistamines as inverse agonists (not antagonists or blockers) with immunoregulatory effects. Unlike first (old)-generation H(1)-antihistamines introduced from 1942 to the mid-1980s, most of the second (new)-generation H(1)-antihistamines introduced subsequently have been investigated extensively with regard to clinical pharmacology, efficacy, and safety; moreover, they are relatively free from adverse effects and not causally linked with fatalities after overdose. Important advances include improved nasal and ophthalmic H(1)-antihistamines with rapid onset of action (in minutes) for allergic rhinitis and allergic conjunctivitis treatment, respectively, and effective and safe use of high (up to 4-fold) doses of oral second-generation H(1)-antihistamines for chronic urticaria treatment. New H(1)-antihistamines introduced for clinical use include oral formulations (bilastine and rupatadine), and ophthalmic formulations (alcaftadine and bepotastine). Clinical studies of H(3)-antihistamines with enhanced decongestant effects have been conducted in patients with allergic rhinitis. Additional novel compounds being studied include H(4)-antihistamines with anti-inflammatory effects in allergic rhinitis, atopic dermatitis, and other diseases. Antihistamines have a storied past and a promising future.
Department of Pediatrics&Child Health and the Department of Immunology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada. email@example.com