Azelastine¿¡ ´ëÇÑ Mechanism_Of_Action Á¤º¸ Antihistamines such as azelastine appear to compete with histamine for histamine H1- receptor sites on effector cells (mast cells). The antihistamines antagonize those pharmacological effects of histamine which are mediated through activation of H1- receptor sites and thereby reduce the intensity of allergic reactions and tissue injury response involving histamine release.
Pharmacology
Azelastine¿¡ ´ëÇÑ Pharmacology Á¤º¸ Azelastine is a relatively selective histamine H1 antagonist and an inhibitor of the release of histamine and other mediators from cells (e.g. mast cells) involved in the allergic response. Based on in vitro studies using human cell lines, inhibition of other mediators involved in allergic reactions (e.g. leukotrienes and PAF) has been demonstrated with azelastine. Decreased chemotaxis and activation of eosinophils has also been demonstrated.
Azelastine¿¡ ´ëÇÑ ´Ü¹é°áÇÕ Á¤º¸ In-vitro studies in human plasma indicate that the plasma protein binding of azelastine and N-desmethylazelastine are approximately 88% and 97%, respectively.
Half-life
Azelastine¿¡ ´ëÇÑ ¹Ý°¨±â Á¤º¸ Elimination half-life (based on intravenous and oral administration) is 22 hours. Elimination half-life of the active metabolite, desmethylazelastine, is 54 hours (after oral administration of azelastine).
Absorption
Azelastine¿¡ ´ëÇÑ Absorption Á¤º¸ Absorption of azelastine following ocular administration was relatively low. Systemic bioavailability is approximately 40% after nasal administration.
Azelastine¿¡ ´ëÇÑ Biotransformation Á¤º¸ Azelastine hydrochloride is oxidatively metabolized to the principal metabolite, N-desmethylazelastine, by the cytochrome P450 enzyme system, however the exact cytochrome P450 isoenzyme involved has not been determined. The major metabolite, desmethylazelastine, also has H1-receptor antagonist activity.
Toxicity
Azelastine¿¡ ´ëÇÑ Toxicity Á¤º¸ Not Available
Drug Interactions
Azelastine¿¡ ´ëÇÑ Drug_Interactions Á¤º¸ Not Available
Azelastine¿¡ ´ëÇÑ Description Á¤º¸ Azelastine is an antihistamine and mast cell stabilizer available as a nasal spray for hay fever and as eye drops for allergic conjunctivitis.
The database contains the following fields: The generic name of each chemical For module A10 (liver enzyme composite module): Overall activity category for each compound (A for active, M for marginally active, or I for inactive) based on the number of active and marginally active scores for each compound at the five individual endpoints (see research article for full description of method) Number of endpoints at which each compound is marginally active (M) Number of endpoints at which each compound is active (A) For modules A11 to A15 (alkaline phosphatase increased, SGOT increased, SGPT increased, LDH increased, and GGT increased, respectively): Overall activity category for each compound (A for active, M for marginally active, or I for inactive) based on the RI and ADR values (see the research article for full description of method) Number of ADR reports for each compound, given as <4 or ¡Ã4 Reporting Index value for each compound, except where no shipping units were available (NSU) Group 1 comprises of compounds for which ADR data were available for the first five years of marketing, so when no ADR reports were listed during this period the compounds were evaluated as inactive. Group 2 comprises of compounds for which a 'steady state' period of ADR data were available (1992-1996). In cases where no ADR reports were filed during this period, the compounds were scored as 'NA' (data not available) since they may have had one or more ADR reports during their first five years of marketing which should not be negated by a lack of ADR reports during the steady-state period. AZELASTINE [GGT Increase] [Composite Activity] (Score)I (Marginal) 0 (Active) 0