Levocet Mechanism of Action

Pharmacology: Pharmacodynamics: Mechanism of action: Levocetirizine is the active R-enantiomer of cetirizine, a second generation antihistamine. The drug is selective antagonist of histamine H1-receptors and as a group, is less sedating.
Pharmacokinetics: Levocetirizine is rapidly and extensively absorbed following oral administration, with peak plasma concentration usually attained in 0.9 hour. A high-fat meal reduces peak plasma concentration by about 36% and delays time to peak plasma concentration by about 1.25 hours, but does not affect AUC. A high-fat meal delays drug absorption but completely absorbed. The average apparent volume of distribution is 0.4 L/kg. Levocetirizine is approximately 91-92% bound to plasma proteins (mainly albumin). The extent of metabolism of levocetirizine is less than 14% of dose by aromatic oxidation, N-dealkylation, O-dealkylation and taurine conjugation. Levocetirizine is excreted in urine; 85.4% (via glomerular filtration and active tubular secretion) and excreted in the feces 12.9%. The elimination half-life is 8-9 hours in adults.