December 9, 2022

Common antihistamine triggers repair of the optic nerve


Multiple Sclerosis Patients Show ‘Exciting’ Repair Results After Hay Fever Medication


In a world first, a drug has been discovered that can reverse damage to the nerves of the eye caused by multiple sclerosis (MS).

This long-sought after result was achieved through the use of a common drug, the antihistamine clemastine fumarate, in the preliminary study presented on Tuesday April 12 at the annual meeting of the American Academy of Neurology in Vancouver, Canada.

A group of 50 people, who were diagnosed with MS an average of five years ago, were given either the antihistamine or a placebo for three months. The two groups then switched.

The participants’ vision was tested throughout the study.

One test recorded the time it takes for a nerve signal to travel from the retina to the visual cortex – a measurement that is typically slowed down in MS patients because the protective coatings around their nerves are attacked by their own immune systems.

In the study, delays in this nerve transmission were reduced by an average of two milliseconds in each eye for patients receiving the antihistamine. The research team concluded that this improvement could demonstrate that the protective myelin layer of the optic nerve had been repaired.

Dr Ari Green, a researcher at the University of California at San Francisco, said: “Although the improvement in vision appears modest, this study is promising because it is the first time that a medication can eventually reverse the damage caused by MS.

Dr Green added: “[The] the results are preliminary, but this study provides a framework for future MS repair studies and will hopefully herald findings that will improve the brain’s innate ability to repair itself.

Dr Green said follow-up studies are needed before doctors can recommend the antihistamine for people with MS.

The university team identified clemastine fumerate as a drug that could help repair the brain several years ago, he explained.