Xynoz Mechanism of Action

Pharmacology: Pharmacodynamics: Desloratadine is a non-sedating long-acting histamine antagonist with potent, selective peripheral H1-receptor antagonist activity. Desloratadine has demonstrated antiallergic, antihistaminic and anti-inflammatory activities. After oral administration, desloratadine selectively blocks peripheral histamine H1-receptors because the drug is effectively excluded from entry to the central nervous system.
Based on reported data, desloratadine inhibits the broad cascade of events that initiate and propagate allergic inflammation, including: the release of proinflammatory cytokines including IL-4, IL-6, IL-8, IL-13; the release of important proinflammatory chemokines such as RANTES (Regulated upon Activation, Normal T-cell Expressed and Secreted); superoxide anion production by activated polymorphonuclear neutrophils; eosinophil adhesion and chemotaxis; the expression of the adhesion molecules such as P-selectin; IgE-dependent release of histamine, prostaglandin (PGD2), and leukotriene (LTC4); the acute allergic bronchoconstrictor response and allergic cough in animal models.
At the recommended adult dose of 5 mg daily, there was no excess incidence of somnolence and not affect standard measures of flight performance including exacerbation of subjective sleepiness or task related to flying. Also, Xynoz tablet at a dose of 7.5 mg daily does not affect psychomotor performance. Based on reported data, at a dose 20 mg daily for 14 days resulted in no statistical or clinical cardiovascular effect. At a dose 45 mg daily for 10 days, no prolongation of the QTc interval was reported.
No clinically relevant changes in desloratadine plasma concentrations were observed when taken concomitantly with ketoconazole, erythromycin, azithromycin, fluoxetine and cimetidine.
Based on literature, co-administration of alcohol did not increase the alcohol-induced impairment in performance or increase in sleepiness. No significant differences were found in the psychomotor test results, whether administered alone or with alcohol.
In adult and adolescent patients with allergic rhinitis, Xynoz tablet was effective in relieving symptoms such as sneezing, nasal discharge and itching, congestion/stuffiness, as well as ocular itching, tearing and redness, and itching of palate. Xynoz tablet effectively controlled symptoms for 24 hours.
Based on the available data, Xynoz tablet was effective in relieving pruritis and decreasing the size and number of hives as early as 1 day after initiation of treatment in adults and adolescence with chronic idiopathic urticaria (CIU). The effects were sustained over the 24-hour dosing interval. Treatment with Xynoz tablet also improved sleep and daytime function, as measured by reduced interference with sleep and routine daily activities.
Xynoz tablet was effective in alleviating the burden of seasonal allergic rhinitis as shown by the total score of the rhino-conjunctivitis quality of life questionnaires. The greatest amelioration was seen in the domains of practical problems and daily activities limited by symptoms.
Pharmacokinetics: Absorption: Desloratadine plasma concentrations can be detected within 30 minutes of administration. Desloratadine is well absorbed with maximum concentration achieved after approximately 3 hours; the terminal phase half-life is approximately 27 hours. The degree of accumulation of desloratadine was consistent with its half-life (approximately 27 hours) and a once daily dosing frequency. The bioavailability of desloratadine was dose proportional over the range of 5 mg to 20 mg.
Distribution: Desloratadine is moderately bound (83 % - 87 %) to plasma proteins. There is no reported data on desloratadine accumulation following once daily dosing (5 mg to 20 mg) for 14 days.
Biotransformation: Desloratadine does not inhibit CYP3A4 or CYP2D6 and is neither a substrate nor an inhibitor of P-glycoprotein.
Elimination: There was no effect of food (high-fat, high caloric breakfast) and grapefruit juice on the disposition of desloratadine.