C Polymodal Receptors (CPN)

According to the book I am reading [Pain Medicine: The Requisites in Anesthesiology], primary hyperalgesia is believed to be the result of the sensitization of previously "silent / sleeping" CPN's from mediators on inflammation, such as bradykinin, prostaglandins, serotonin, and histamine.

Now if this is accurate, why do we not see antihistamines being used as part of balanced analgesia...or do we?