At present, there is no safe, widely applicable treatment that is capable of reducing the rate at which disability advances in secondary progressive multiple sclerosis (SPMS). There is good evidence that the primary cause of disability is axonal degeneration within the CNS, so there is considerable interest in developing treatments which can protect axons from degeneration. Experimental work by members of our group has established that axons may degenerate upon exposure to the inflammatory mediator nitric oxide. The mechanism of the damage implies that protection might be afforded by the novel approach of partially blocking sodium channels, and our group and others have recently demonstrated that drugs including flecainide, phenytoin and lamotrigine can reduce axonal degeneration when optic nerves or spinal roots are exposed to nitric oxide, and in experimental autoimmune encephalomyelitis.