PF-04457845 is an orally active, irreversible inhibitor of fatty acid amide hydrolase (FAAH; IC50 = 7.2 nM) that is selective against other serine hydrolases. It is a covalent inhibitor that carbamylates the active site serine nucleophile of FAAH. In a rat model of inflammatory pain, oral administration of 0.1 mg/kg PF-04457845 has been shown to reduce inflammatory pain with efficacy comparable to that of naproxen.
