Hazards of Concomitant Use or Discontinuation of Cytochrome P450 2D6 Inhibitors The concomitant use of tramadol hydrochloride tablets with all cytochrome P450 2D6 inhibitors (e.g., amiodarone, quinidine) might bring about an increase in tramadol plasma ranges in addition to a minimize while in the levels of the Lively metabolite, M1.The effects of