Hazards 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 lead to an increase in tramadol plasma degrees in addition to a lessen in the amounts of the Energetic metabolite, M1.The effects of