- Need for any concomitant medication that is moderate or strong CYP inhibitors including CYP3A4, CYP2D6, CYP2C9, and CYP2C19, or P-gp inhibitor. Need for other antidiabetic drugs except for metformin. Other common concomitant medications in diabetic patients may be allowed (eg, aspirin and thyroid hormones) upon agreement between the Sponsor and the PI.