Desloratadine

Desloratadine is a potent antagonist for human histamine H1 receptor with IC50 of 51 nM.

Comparative efficacy of bilastine, desloratadine and rupatadine in the suppression of wheal and flare response induced by intradermal histamine in healthy volunteers.[Pubmed:27659218]

Curr Med Res Opin. 2017 Jan;33(1):129-136.

OBJECTIVE: To compare the peripheral antihistaminic activity of bilastine, rupatadine and Desloratadine in inhibiting the histamine-induced wheal and flare (W&F) response. RESEARCH DESIGN AND METHODS: Twenty-four healthy volunteers aged 18-40 years participated in this crossover, randomized, double-blind, placebo-controlled clinical study. Subjects received single doses of bilastine 20 mg, Desloratadine 5 mg, rupatadine 10 mg and placebo. W&F responses induced by intradermal injection of histamine 5 mug were evaluated before treatment (basal value) and at 0.5, 1, 2, 4, 6, 9, 12 and 24 hours after treatment. Fifteen minutes after histamine injection, W&F surface areas (cm(2)) were quantified using the Visitrak System. Itching sensation was evaluated using a 100 mm visual analog scale. EudraCT number: 2015-000790-13. MAIN OUTCOME MEASURES: The primary outcome measure was the percentage reduction in W&F areas after each active treatment compared with corresponding basal values. RESULTS: Bilastine induced the greatest inhibition in wheal area and was significantly superior to Desloratadine and rupatadine from 1 to 12 hours (both p < .001). Rupatadine and Desloratadine were better than placebo without differences between them. Maximum wheal inhibition occurred at 6 hours (bilastine 83%, Desloratadine 38%, rupatadine 37%). Onset of action was 1 hour for bilastine and 4 hours for Desloratadine and rupatadine. Bilastine was significantly superior to Desloratadine and rupatadine for flare inhibition from 1-24 hours (both p < .001) with an onset of action at 30 minutes. Bilastine was significantly better than Desloratadine (2-12 hours; at least p < .05) and rupatadine (2-9 hours; at least p < .01) for reducing itching sensation. Neither Desloratadine nor rupatadine significantly reduced itching compared to placebo. All active treatments were well tolerated. CONCLUSIONS: Bilastine 20 mg induced significantly greater inhibition of the W&F response compared with Desloratadine 5 mg and rupatadine 10 mg throughout the 24 hour study period, and had the fastest onset of action. Only bilastine significantly reduced itching sensation versus placebo.

The pharmacologic profile of desloratadine: a review.[Pubmed:11243504]

Allergy. 2001;56 Suppl 65:7-13.

Desloratadine is a new agent for the treatment of diseases such as seasonal allergic rhinitis and chronic urticaria. The pharmacologic profile of Desloratadine offers particular benefits in terms of histamine H1-receptor binding potency and H1 selectivity. Desloratadine has a half-life of 21-24 h, permitting once-daily dosing. No specific cautions are required with respect to administration in renal or hepatic failure, and food or grapefruit juice have no effect on the pharmacologic parameters. No clinically relevant racial or sex variations in the disposition of Desloratadine have been noted. In combination with the cytochrome P450 inhibitors, ketoconazole and erythromycin, the AUC and Cmax of Desloratadine were increased to a small extent, but no clinically relevant drug accumulation occurred. With high-dose treatment (45 mg/day for 10 days), no significant adverse events were observed, despite the sustained elevation of plasma Desloratadine levels. Specifically, Desloratadine had no effects on the corrected QT interval (QTc) when administered alone, at high dose, or in combination with ketoconazole or erythromycin. Preclinical studies also show that Desloratadine does not interfere with HERG channels or cardiac conduction parameters even at high dose. Desloratadine is nonsedating and free of antimuscarinic/anticholinergic effects in preclinical and clinical studies. Novel antiallergic and anti-inflammatory effects have also been noted with Desloratadine, a fact which may be relevant to its clinical efficacy.