Comparative analysis of the sedative effects of mequitazine and other antihistaminic drugs: Review of the literature

Background: Antihistamines (H-1-receptor antagonists) are widely prescribed to treat symptoms of seasonal and perennial allergic rhinitis and chronic urticaria. Drowsiness and impairment of cognition and psychomotor performan ce have been reported as adverse events in many trials, and all antihistami nes appear to have some sedative properties. Sedation, however, may be a di rect result of allergic rhinitis, and the degree of sedation may depend on each individual's response to antihistamine therapy, and thus cannot be pre dicted. Objective: The purpose of this review was to compare the adverse sedative e ffects of mequitazine with those of other antihistamines used in clinical p ractice. Methods: A literature search was conducted to identify all available public ations from the MEDLINE(R) and Excerpta Medica databases on mequitazine and review articles on nonsedating antihistamine drugs in peer-reviewed journa ls from 1975 to 1999. Additional publications on mequitazine mere provided, by the manufacturer of the drug. The clinical outcomes of drowsiness and f atigue in patients with allergic rhinitis were the focus of this comparativ e analysis. Conclusions: The classification of antihistamines based on their chemical s tructure alone is misleading. Based on our review of all available product literature on mequitazine and recently published reviews of nonsedating ant ihistaminic drugs, mequitazine demonstrates a clinically proven low-sedatio n profile, similes to that seen with current antihistamines, which are freq uently reported to be nonsedating, Mequitazine has a low propensity to indu ce drowsiness, comparable to that of cetizizine and loratadine. Thus, it, d iffers from truly sedative antihistaminic drugs, such as dexchlorpheniramin e, which produce drowsiness and fatigue in patients with atopy to a degree that is measurably different from placebo. Key words: mequitazine, review, nonsedating, antihistamines.