Fatigue is commonly associated with multiple sclerosis and leads to significant disability and loss of quality of life. Several kind of interventions have been carried out, but definitive evidence on their relative efficacy and tolerability are not available. As quite recently it has been hypothesised a relationship between low carnitine levels in the blood and fatigue, and several studies showed that supplementation with carnitine produced improvement in fatigue symptoms. The Authors decided to perform a systematic review to assess the possible efficacy of carnitine in improving fatigue and to identify any adverse events in relapsing-remitting and secondary progressive MS patients. Most of the studies did not meet the inclusion criteria of methodological quality, but one with the enrollement of 36 patients for 12-month intervention with carnitine associated with amantadine, another drug commonly used to improve fatigue.
From this report, it is unclear if carnitine supplementation in MS patients improves fatigue, reduces the disability that results from fatigue or improves quality of life. It is also unclear if the use of carnitine for MS related fatigue is safe. —Cochrane May 2012