ND

Treatment tested

• Naltrexone

  Opioid receptors; mu/kappa/delta antagonist

Inclusion: Subjects must meet all inclusion criteria in order to be eligible for the study diagnosis of Multiple Sclerosis according McDonald criteria, of primary progressive type. Women of child-bearing potential must practice an acceptable method of birth control. Subjects must be between the ages of 18-60 years inclusive. Subjects with EDSS score 3.0 5.5 Subjects must be affected with spasticity scored by Ashworth scale as 1 4 or pain scored by VAS as 1 10 or fatigue scored by Fatigue Severity Scale as 3 7 disease duration of at least 2 year Stable course for the previous 6 months Use of gabaergic or serotoninergic drugs i.e.baclofen, antidepressive .. must be optimized before start of the study and stabilize during study period Exclusion: Any of the following conditions will exclude the subject from entering the study Pregnancy or lactation. Use of opioid analgesics or any opioid-containing drug seven to ten days before initiating treatment with naltrexone and during study period. Use of Novantrone or Cyclofosfamide or IFN Beta or steroids during study period Subjects with acute hepatitis or liver failure Subjects with a clinically significant or unstable medical or surgical condition which would preclude safe and complete study participation. Such conditions may include cardiovascular, pulmonary, hepatic, gastrointestinal, renal, or metabolic diseases or malignancies. Any medical or psychiatric conditions that affect the subject s ability to give informed consent, or to complete the study.

EFFICACY Changes of at least one point from baseline in spasticity or pain or fatigue