<p>Cinacalcet is a strong CYP2D6 inhibitor and may increase serum concentrations of amitriptyline, nortriptyline and desipramine. Cinacalcet may decrease serum concentrations of tacrolimus. CYP3A4 inhibitors such as ketoconazole, erythromycin may increase plasma concentrations of Cinacalcet.</p>