Pharmacology
Mechanism of Action
Histamine H1-receptor antagonist; competes with histamine on effector cells in the gastrointestinal tract, blood vessels and respiratory tract
Absorption
Peak plasma concentration: 114 ng/mL
Peak serum time: 1 hr
Duration: >24 hr ( suppression of skin wheal and flare reactions
Distribution
Protein bound: 93%
Vd: 0.56 L/kg
Metabolism
Metabolism: Liver; low first pass
Limited extent by oxidative O-dealkylation to inactive metabolite
Elimination
Half-life: 7.9hr
Excretion: Urine (70%); feces (10%)