Threats of Concomitant Use or Discontinuation of Cytochrome P450 2D6 Inhibitors The concomitant utilization of tramadol hydrochloride tablets with all cytochrome P450 2D6 inhibitors (e.g., amiodarone, quinidine) might result in a rise in tramadol plasma levels in addition to a minimize during the levels of the active metabolite, M1.Teach patients a