The purpose of this study is to observe pharmacokinetics and safety of nalfurafine hydrochloride in patients receiving hemodialysis.

Inclusion Criteria:

• Patients with chronic renal failure who receive dialysis three times a week on a regular basis and do not expect an important change in treatment nor a rapid change in conditions
• Patients aged 20 years or older
• Patients whose post-dialysis BMI measured at the nearest time before the singing day is in the range of 70 ~ 130 %
• Patients who can understand and follow instructions and participate in the study during the entire study period
• Patients who signed the informed consent form before participating in the study

Exclusion Criteria:

• Patients who have confirmed malignant tumor

• Patients with cognitive impairment including depression, schizophrenia and dementia

• Patients with hepatic cirrhosis as a complication

• Patients with drug allergy to opioids

• Patients with drug dependency or allergic disease (including skin response to UV radiation)

• Patients who participated in other study and received the investigational drug within 1 month before the signing day

• Patients who participated in other TRK-820 study within 4 weeks before the signing day

• Pregnant or lactating women or premenopausal women of childbearing potential who do not conduct contraception

• Patients who received any of the following drugs within 2 weeks before Day 1

  1. Azole antifungal agents

     1. Ketoconazole
     2. Fluconazole
     3. Itraconazole
     4. Clotrimazole

  2. Macrolide antibiotics

     1. Erythromycin
     2. Midecamycin
     3. Josamycin
     4. Roxithromycin
     5. Clarithromycin
     6. Triacetyloleandomycin

  3. Ritonavir

  4. Cyclosporine

  5. Nifedipine

  6. Cimetidine

  7. Amiodarone

• Patients who had the following drinks and foods within 2 weeks before Day 1

  1. Foods and drinks containing grape fruit juice
  2. Food and drinks containing St. John's wort

• Patients who participated in other clinical study during the period between the singing day and hospitalization (Day 1)

• Patients who smoked and drank from three months before the signing day

• Patients who are ineligible for the clinical study for other reasons at the investigator's discretion