THE DEFINITIVE GUIDE TO TRAMADOL (RETARD)

Opioid activity is due to each lower affinity binding with the parent compound and better affinity binding with the O-demethylated metabolite M1 to μ-opioid receptors. In animal versions, M1 is as many as 6 occasions far more potent than tramadol in generating analgesia and 200 moments far more potent in μ-opioid binding.         healthdi