Experimental Medications: Other Therapeutic Strategies
It is hypothesized that accumulation of salt and potassium within the cells of MS lesions may contribute to cellular injury and neurodegeneration (the breakdown of nerves). This hypothesis would suggest that by blocking certain channels in these cells, the buildup of these molecules can be prevented and neurodegeneration can be prevented. This strategy was tested and data presented in 2013,66 looking at the use of amiloride – a potassium-sparing diuretic approved for the treatment of high blood pressure and congestive heart failure – that may have this neuroprotective activity.
The effect of amiloride was studied in 14 people with PPMS using MRI markers of neurodegeneration as outcome measures of neuroprotection. Patients with PPMS underwent MRI scans before and during amiloride treatment (at a dose used for high blood pressure) for a period of three years.
Researchers found a significant reduction in the development of brain atrophy, and a slowing of the development of disability during the treatment phase, suggesting that amiloride may exert neuroprotective effects in patients with progressive MS. Because amiloride does not readily cross the blood-brain barrier, it is not clear the precise mechanism for the results. This pilot study was the first translational study on neuroprotection using amiloride, and supports further investigation of this drug as a potential neuroprotective agent in MS. A phase II trial studying this agent in optic neuritis67 was initiated in 2013 and is expected to run through 2015.