Here's an abstract about the Italian study paulmur posted on, but this one is from the just completed European Neurological Society meeting.
A pilot trial of low-dose naltrexone in primary progressive multiple sclerosis
M. Gironi, F. Martinelli Boneschi, P. Sacerdote, C. Solaro, R. Cavarretta, L. Moiola, M. Zaffaroni, V. Pilato, M. Cursi, M. Radaelli, S. Bucello, V. Martinelli, R. Nemni, G. Comi, G. Martino on behalf of the Italian Federation of Multiple Sclerosis
Introduction: Naltrexone is an orally semi synthetic opiate antagonist licensed, in a 50 mg dose, for the treatment of alcohol and heroin addiction, while at lower doses it is supposed to exert an agonistic activity triggering a prolonged up regulation of beta-endorphins (BE), an endogenous opioid with immunomodulatory functions. A symptomatic effect on spasticity, pain and fatigue of low dose naltrexone (LDN) in Multiple Sclerosis (MS) has been reported in anecdotic observations.
Methods: A six-month pilot multicentre open-label trial with LDN (5 mg/die) has been carried out in 40 patients (pts) affected by primary progressive (PP)MS. Safety and efficacy of LDN on spasticity, pain, fatigue and depression were the major outcome measures of the study. Clinical and biochemical evaluations were serially performed at follow-up visits. BE levels in peripheral blood mononuclear cells (PBMC), as well as allelic variants of the gene coding for the mu opioid receptors (OPRM1) and its mRNA levels were also measured. Validated scales of measures (Ashworth, Visual Analogue Scale, Beck, Fatigue Severity Scale and SF36) were used for testing spasticity, pain, depression, fatigue and quality of life.
Results: Five drop-outs and two unrelated serious adverse events occurred during the study. Transitory haematological abnormalities (increase of liver enzymes), urinary tract infections, mild agitation and sleep disturbance were the commonest adverse events. The PBMC BE levels increased in all patients since the 3rd month of therapy and were still raised 1 month after the end of therapy discontinuation at a statistically significant levels. No change was found for mRNA levels of OPRM1and no correlation between allelic variants and clinical responsiveness. According to pre-defined criteria of responsiveness for spasticity, fatigue, pain or depression, more than half of patients reported an improvement in at least one of these secondary outcomes. As regards quality of life, there was a general trend of improvement between final and baseline evaluation. Only 3 patients experienced EDSS clinical progression of the disease during the study.
Conclusion: Our findings support a safe profile for LDN in PPMS, further studies should be considered in order to explore the potential efficacy of the drug in MS patients.