Challenges 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) could cause an increase in tramadol plasma levels plus a decrease in the levels of the Lively metabolite, M1.Rapid discontinuation has also bee… Read More