Pifarre et al. Acta Neuropathol. 2011 Apr;121(4):499-508.
Sildenafil (aka Viagra), commonly used to treat sexual dysfunction in men with MS, has been reported to be neuroprotective. In this study, the investigators showed that sildenafil reduces the clinical signs of disease in a mouse model of MS.
"I wonder if Pfizer would be interested in taking this forward in humans? I suspect not with Viagra, but may be one of the longer acting compounds in this class of drugs."