6. Concomitant use of Cytochrome (CYP3A4) inhibitors (See Appendix 1-2) is not allowed. The use of cytochrome (CYP2D6) substrates (Appendix 1, table 0-3) should be done with caution. If drugs that are CYP2D6 substrates arte to be continued, patients should be carefully monitored and may require dose titration or dose reduction of the CYP2D6 substrate.