PF-03654764 is an orally active, potent, and selective histamine H3 receptor antagonist that inhibits human H3 and rat H3 with Ki values of 1.2 nM and 7.9 nM, respectively.PF-03654764 is often co-administered with Fexofenadine for the treatment of allergic rhinitis.

Store at -20℃ for one year（Powder）；Store at 2-4℃ for two weeks；Store at -20℃ for six months after dissolution.

H3 receptor:7.9 nM (Ki,rat ), H3 receptor:8.98 (pKi,human), H3 receptor:1.2 nM (Ki) (human), H3 receptor:8.10 (pKi,rat)

In a whole cell assay, PF-03654764 exhibits pKi values of 8.98 and 8.10 for human H3 and rat H3, respectively. In HEK-293 cells, PF-03654764 demonstrates pKi values of 8.84 and 7.73, as well as Ki values of 1.4 nM and 19 nM for human H3 and rat H3, respectively. Notably, PF-03654764 displays >1000-fold selectivity for the H3 receptor over the other histamine receptor subtypes[1].Regarding its pharmacokinetics, PF-03654764 has a half-life (T1/2) of 120 minutes in human liver microsomes (HLM) and a clearance (CLh) of less than 5 mL/min•kg in HLM[2].

In Sprague-Dawley rats, PF-03654764 administered orally at a dose of 10 mL/kg for 14 days results in a Cmax of 8057 ng/mL and an AUC0-24 of 67400 ng•h/mL[2].
Similarly, in beagle dogs, oral administration of PF-03654764 at a dose of 1 mL/kg for 7 days yields a Cmax of 6302 ng/mL and an AUC0-24 of 18175 ng•h/mL[2].