Biomedical subjects
J M Negro-Alvarez
Publications and source records attributed to J M Negro-Alvarez.
Chronic idiopathic urticaria treatment.
Chronic idiopathic urticaria (CIU) is a common skin condition that affects 0.1-3 % of people in the USA and Europe and accounts for nearly 75 % of all chronic urticaria cases. Up to 40 % of patients who have chronic urticaria for more than 6 months still have urticarial wheals 10 years later. The therapeutic management should first be oriented towards palliation of symptoms. A 2 % solution of ephedrine as a local spray is very useful for oropharyngeal edema. H1 antihistamines with a low potential for sedation are the most important first-line treatment. Combinations of various antihistamines may be useful in suppressing symptomatology. These include: a) First generation H1 antihistamines; b) Combinations of first and second generations using non-sedating agents in the morning and first generation drugs at night; c) Combinations of second generation antihistamines; d) Combination of doxepin with a first or second generation antihistamine; e) Combination of an H2 anti-receptor antihistamine (eg, cimetidine or ranitidine) with a first or second generation antihistamine. Preliminary reports suggest that desloratadine and anti-leukotrienes may be effective in treating some patients with chronic idiopathic urticaria.
Antiallergic properties of antihistamines.
Histamine is a major mediator of the allergic reaction, and histamine H1-receptor antagonists have a long history of clinical efficacy in a variety of allergic disorders. The pathogenesis of allergic disease is complex, involving not only histamine and mast cell-derived tryptase, but also eosinophil and neutrophil derived mediators, cytokines, and intercellular adhesion molecules (ICAM-1). A number of "in vitro" and "in vivo" studies have been performed to assess the clinical effectiveness of antihistamines in inhibiting the allergen-induced inflammatory process in the skin and mucosa. In vitro human studies have shown that high concentration of second generation antihistamines can block inflammatory mediator release from basophils and mast cells, and reduce ICAM-1 expression in epithelial cell lines. In vivo studies have also shown an effect on the allergen-induced inflammatory reaction; both oral and intranasal antihistamines cause a reduction in nasal symptoms and inflammatory cell influx. Analysis of secretory fluids and tissues after challenge indicates that antihistamines interfere with mediator release. Recruitment of inflammatory cells to the site of the allergic insult is also disturbed by antihistamines of second-generation, suggesting that these drugs may inhibit upregulation of molecules involved in cell adhesion and migration, and perhaps they may interfere with the cytokine cascade through their ability of stabilizing mast cells and of limiting the incursion of inflammatory cells. This article reviews available human data on the antiallergic effects of antihistamines.
Pharmacologic therapy for urticaria.
Treatment of chronic urticaria presents a challenge to both practitioner and patient. Traditional H1 antagonists with good efficacy but substantial side effects are being supplanted in many cases by nonsedating H1. Combinations of H1 and H2 antagonists offer improved results for selected patients. Second-line therapies include a wide range of drugs such as doxepin, dapsone, attenuated androgens, calcium antagonists, antimalarials, gold and methotrexate. The most effective and regularly used second-line agents are corticosteroids. These are best limited to short term crisis management, except in severe recalcitrant cases, and in patients with pressure urticaria or urticarial vasculitis. Further development and investigation of mast cell stabilisers and inhibitors of urticaria mediators other than histamine hold promise. A better understanding of the underlying pathogenesis remains the greatest hope of formulating rational and effective therapy.