Evaluation of different classes of histamine H1 and H2 receptor antagonist effects on neuropathic nociceptive behavior following tibial nerve transection in rats

These results indicate that both blood brain barrier penetrating (chlorpheniramine) and poorly penetrating (fexofenadine) histamine H1 receptor antagonists could improve the neuropathic pain sign, but only the blood brain barrier penetrating histamine H2 receptor antagonist (ranitidine) could produce anti-allodynic effects in the TNT model of neuropathic pain in rats.