Cardizem CD, Cartia XT, Dilt-CD: 120-180 mg/day PO; titrate over 7-14 days; maintenance range usually 120-320 mg/day; not to exceed 480 mg/day. DilacorXR, Dilt-XR: 120 mg/day PO; titrate after 7-14 days; maintenance range usually 120-320 mg/day; not to exceed 540 mg/day.