Pramipexole for Restless Leg Syndrome in Peritoneal Dialysis Patients

Inclusion Criteria: 1. PD patients (aged ≥18 years) are dialyzed with lactate-buffered glucose dialysate, using a twinbag connection system (Baxter Healthcare, Guangzhou, China). 2. For entry , all patients are required to meet all diagnositic criteria of the International RLS Study Group (IRLSSG), to have a baseline total score \>15 on the Study Group's International RLS Rating Scale (IRLS), and to have experienced RLS symptoms at least 2-3 days per week throughout the perior 3 months. 3. Each patient should write informed consent. 4. All patients are required to be interviewed to the frequency required by the research process. Exclusion Criteria: 1. Patients with severe gastrointestinal illness can not tolerate oral drugs. 2. Patients who work on a shift schedule are not allowed to participate. 3. Women with childbearing potential are excluded for pregnancy, inadequate contraception, or current breastfeeding of a child. 4. Patients are also excluded for current use (within 14 days before baseline) of medications that might affect RLS symptoms, e.g., levodopa, dopamine agonists or antagonists, hypnotics, lithium formulations, or antidepressants. 5. Patients with serum ferritin ≤200 ng/ml, or Hb \<110g/L, or Kt/V \<1.7 are excluded. 6. Patients with severe and unstable inflammation disease (active systemic infection, acute cardiovascular disease, active liver disease, active connective tissue disorder, ,and cancer within 1 year of radiotherapy and chemotherapy, )