Double-blind comparison of two antihistamines: mequitazine and dexchlorpheniramine

A dose‐ranging study of the effects of mequitazine on actual driving, memory and psychomotor performance as compared to dexchlorpheniramine, cetirizine and placebo

“…Only few studies had examined the sedative effects of mequitazine prior to the present study. Most of them indicated that mequitazine was non-sedating on the basis of questionnaires [11,12,14]. Studies employing objective laboratory tests reported that mequitazine 5 mg produced no impairment of psychomotor and cognitive functions [16,20].…”

“…Terfenadine, astemizole and mequitazine were among the first compounds to be introduced as non-sedating second-generation antihistamines in the 1980's. Many studies showed that therapeutic doses of these and subsequent drugs did not cause sedation [11][12][13][14][15][16]. Consequently, it was suggested that second-generation antihistamines are not able to cross the blood-brain barrier and do not interact with histamine brain receptors.…”

“…Although mequitazine was one of the earliest second-generation antihistamines on the market, only few comparative studies were performed to actually establish its sedative properties. These studies generally demonstrated that therapeutic doses of mequitazine 5-10 mg produced no or less psychomotor impairment and subjective drowsiness as compared to first-generation antihistamines [11,12,14,16,20]. Most studies, however, used only subjective tests, small sample sizes or a specific population.…”

Does Mast Cell Protection plus Mediator Antagonism Surpass the Effect of a Classic Antihistaminic in the Treatment of Chronic Urticaria?

“…The peculiar, twofold activity of oxat omide, including antagonism of more mediators than histamine alone, probably accounts for these findings. Treatment failure in 1 patient with cholinergic urticaria may not be surprising in view of the lack of anticho linergic effects of oxatomide [11], In contrast, such activity is rather marked with mequitazine which provoked severe urine retention in a patient in this study and may, reportedly, produce dry mouth and disturbed accommodation [2], Finally, it was a rewarding observation that the level of daytime sedation of oxatomide (3 cases, not interfering with treatment) is not exceeding that of mequitazine (2 patients, 1 of whom had to discontinue treatment) which, in turn, has been shown to be more convenient in this respect than other frequently used antihistaminics [2,9],…”

“…Pharmaco logical and morphological studies had shown oxatomide to be a potent antiallergic agent by virtue of a twofold effect: not only does it inhibit mast cell degranulation but it also competitively antagonizes histamine, séro tonine and SRS-A [4]. The first experience with oxatomide in chronic urti caria showed that, compared with a placebo, it effectively reduces the symptoms and is well tolerated [3,10,12], To compare, in this condition, oxatomide with a classic H, blocker, we designed a double-blind trial with the phenothiazine mequitazine, which appeared to be a representative antihistaminic in the treatment of various allergic disorders [2,9] and which has been claimed to be relatively free of sedative effects [7].…”