RUPATADINE FUMARATE

Biochem/physiol Actions

Rupatadine (UR-12592) is an orally active, dual histamine H1 and platelet-activating factor (PAF) receptor antagonist (K_i(app) = 100/550 nM against pyrilamine/WEB2086 binding to guinea pig cerebellum/rabbit platelet membranes) that inhibits histamine-induced guinea pig ileum contraction (pA2 = 9.29) and PAF-induced platelet aggregation (IC₅₀ = 0.68 µM/human PRP). Rupatadine blocks histamine-/PAF-induced hypotension (ID₅₀ = 1.4/0.44 mg/kg i.v. rats) and bronchoconstriction (ID₅₀ = 113/9.6 µg/kg i.v. guinea pigs), as well as prevents mortality caused by PAF (ID₅₀ = 0.31 mg/kg i.v. or 3.0 mg/kg p.o. mice) and endotoxin (mice/rats ID₅₀ = 1.6/0.66 mg/kg i.v.) in vivo.