Systematic review of the literature: tratment for central pain in multiple sclerosis

INTRODUCTION: pain is a very common symptom in patients with Multiple Sclerosis, 42 to 65% of patients present it. As the severe symptom, pain in these patients is between 8 to 32%. All central pain syndromes are presented by injury or dysfunction of the central nervous system, causing severe disability and deterioration in the quality of life of patients. OBJECTIVE: to assess the analgesic effectiveness of pharmacotherapies in central pain in patients with Multiple Sclerosis (MS), in order to provide evidence-based recommendations for clinical practice METHODOLOGY: search strategy: we identified randomized trials of pharmacotherapies treatment of central pain in patients with Multiple Sclerosis, MEDLINE (1965-September 2007), EMBASE (2000 to 2007), and Lilacs (1990-2007). Additional reports were identified from the reference lists of retrieved articles. Date of the most recent search: September 2007. Selection criteria: clinical studies randomized controlled double blind, duration of treatment equal to 1 or more days, compared to placebo or one or more pharmacological therapies in patients with Multiple Sclerosis, with a subjective evaluation of pain as primary or secondary results. Data collection and analysis: seven studies were considered eligible, of whom 4 are cannabinoids studies, a study with morphine IV, another with Lidocaina and Mexiletina and finally a combination of Lofepramina, Vitamin B12 and phenylalanine. RESULTS: the inadequate quality of available studies warrants further investigation. Intervention trials with pharmacological therapy (cannabinoids, morphine, lidocaine, mexiletine, lofepramina combination of Vitamin B12, L-phenylalanine) or other intervention undoubtedly require adequate sample sizes, designs, randomized controlled parallel group and clinically relevant outcome measures reliable, and sensitive. But in studies with cannabinoids, it is observed that it is better than placebo, and that in terms of clinical relevance, impact on patient functioning and quality of life related to health has a beneficial effect. CONCLUSIONS: more studies are needed based on clinical evidence, which yield the best results of non-pharmacological or pharmacological treatments, with high efficiency and effectiveness with fewer side effects, which prevent the abandonment of treatment by patients. And to ensure a better quality of life and performance of their daily life activities. Although the evidence that cannabis and single cannabinoids are effective in pain management, are not conclusive, this is enough to order clinical trials of cannabinoids that may provide more clinical information about the effectiveness and presentation of adverse effects. The poor quality of the available studies warranted further investigations.