Antihistamine therapy for spontaneous urticaria: integration of pharmacological approach and clinical experience

The high efficacy and good tolerability of second-generation antihistamines in the treatment of idiopathic urticaria allow for their long-term successful use. Clinical experience accumulated over the past decades and data from modern studies, including meta-analyses, have convincingly demonstrated that many second-generation antihistamines have a wide therapeutic window and maintain a favorable benefit-risk ratio even when used significantly above standard doses. This has led to a reconsideration of previous restrictions and the establishment of a strategy for using high-dose second-generation antihistamines as the standard for patients with an inadequate response to first-line therapy. Currently, international and Russian guidelines have developed a strategy for using high doses of second-generation antihistamines (2–4 times the recommended dose) for resistant and severe forms of chronic spontaneous urticaria accompanied by frequent exacerbations, with the goal of completely eliminating symptoms and achieving sustained remission. It should be noted that increasing the dose is a preferable tactic over switching to a different second-generation antihistamines.

When selecting a specific drug for long-term therapy, especially in patients whose work requires increased alertness or in those with polypharmacy, the pharmacodynamic and pharmacokinetic characteristics of individual agents must be considered. Fexofenadine exhibits a predictable safety profile, lacks sedation, is non-cardiotoxic, and exhibits minimal risk of drug interactions. Furthermore, its efficacy within the high-dose strategy of second-generation antihistamine is among the highest. According to a 2016 meta-analysis evaluating the efficacy of increased doses of second-generation antihistamines, increasing the fexofenadine dose for the treatment of chronic spontaneous urticaria was effective in 83.1 % of cases ― the best result among all second-generation antihistamines studied.