The chronic vision damaged caused by multiple sclerosis may be reversed by using clemastine fumarate, an over-the-counter drug used to treat allergies and colds.
The chronic vision damaged caused by multiple sclerosis (MS) may be reversed by using clemastine fumarate, an over-the-counter drug used to treat allergies and colds, according to findings presented at the American Academy of Neurology’s 68th Annual Meeting in Vancouver in April.
Researchers from the Multiple Sclerosis Center at the University of California, San Francisco studied 50 MS patients with optic neuropathy, the damage to the optic nerve which blocks the information exchange between the eyes and the brain. MS patients included in the study had an average age of 40 years, had the disease for an average time period of five years and had mild disability, though they all had evidence of chronic optic neuropathy.
For the first three months, the patients were given either the antihistamine clemastine fumarate or a placebo, followed by a swap for the remaining two months. The patients performed vision tests at baseline and after five months, including one called a “visual evoked potential.” The time for transmission of signal from the eye to the brain was recorded. Any improvement in the delay was considered an improvement, the researchers said, and the patients needed to record times beyond 118 milliseconds in at least one eye to partake in the study.
Delays were reduced by an average of two milliseconds per patient among those who received clemastine fumarate, the researchers reported.
“This study is exciting because it is the first to demonstrate possible repair of that protective coating in people with chronic demyelination from MS,” study author Ari Green, MD, explained in a press release. “This was done using a drug that was identified at UCSF only two and a half years ago as an agent with the potential to help with brain repair.”
One of the side effects that patients reported was a minimal increase in fatigue while taking the drug. And although larger cohorts are needed to confirm the finding, Green added, medications with more powerful effects are currently in development.
“While the improvement in vision appears modest, this study is promising because it is the first time a drug has been shown to possibly reverse the damage done by MS,” said Green. “Findings are preliminary, but this study provides a framework for future MS repair studies and will hopefully herald discoveries that will enhance the brain's innate capacity for repair.”