In patients w/ mild to moderate renal impairment or mild hepatic impairment concomitantly receiving strong CYP3A inhibitors eg, itraconazole, ketoconazole, the recommended dose is 25 mg once daily. CYP3A/P-gp inducers decrease the plasma conc of mirabegron. Medicines w/ narrow therapeutic index & significantly metabolized by CYP2D6 eg, thioridazine, type 1C antiarrhythmics (eg, flecainide, propafenone) & TCAs (eg, imipramine, desipramine); individually dose-titrated CYP2D6 substrates. In combination w/ digoxin, the lowest dose for digoxin should be initially prescribed.