Description
A selective histamine H1 receptor antagonist; the (R)-enantiomer of cetirizine; binds to the H1 receptor with higher affinity than cetirizine (Kis = 3 and 6 nM, respectively) and is highly selective for H1 over M1-M5 receptors; decreases production of RANTES and eotaxin following antigen stimulation in mouse eosinophils in vitro (MEC = 0.05 µM); dose-dependently decreases histamine-induced nasal rubbing and sneezing in mice (0.01-1% solution)