With oral administration, do not take it with split dose. As a starting dose, cinacalcet 25 mg is administered orally to adults once a day. Thereafter monitoring parathyroid hormone (PTH) and serum calcium concentration in patients based on the serum calcium level or parathyroid hormone (iPTH), the dose is adjusted to 25, 50, 75 mg once a day, and administered orally. However, if the improvement of parathyroid hormone (iPTH) is not confirmed, administer an upper limit of 100 mg per time. In the case of increase, the increase shall be every 25mg, and it is carried out at intervals of at least three weeks. 1. As this drug has a degradation of calcium in the blood, check that the serum calcium level is not low (over 9.0 mg/dL as a standard) and start administration. 2. The serum calcium level is measured once a week at the start of the drug, during the medication measure at least once every two weeks. If the serum calcium level is lower than 8.4 mg/dL, respond as shown in the table below. In order to appropriately judge the efficacy and safety of the drug, the serum calcium level is preferably tested before administration. Further, in the case of hypoalbuminemia (serum albumin value is less than 4.0 g/dL), it is recommended to use the calcium correction. Calcium correction : Corrected calcium (mg/dL) = serum calcium level (mg/dL)-serum albumin level (g/dL) + 4.0 3. Regularly measure parathyroid hormone (iPTH) to ensure that it remains at the control target. It is desirable to measure parathyroid hormone (iPTH) twice a month at the start of the drug and at the time of dose adjustment (about 3 months from the administration as a standard), and once a month after confirming that parathyroid hormone (iPTH) is almost stable. In addition, it is desirable to measure parathyroid hormone (iPTH) before medication in order to properly determine the efficacy and safety of the main agent. 4. Patients with liver disease : Exposure to this drug was 2.4 and 4.2 times higher in patients with moderate and severe liver disease (by Child-Pugh method) than in normal cases (based on AUC), respectively. PTH and serum calcium levels should be closely monitored when the drug is administered in patients with moderate and severe lever disease.