Riluzole is a glutamate receptor blocker used in the treatment of ALS, a form of motor neurone disease.
Glutamate receptor blockers are aimed at controlling one of the chemicals involved in transmitting messages from nerve cell to nerve cell. Excessive glutamate can lead to the loss of nerve fibres and research is looking at the effects of trying to control this as a way of protecting nerves in people with multiple sclerosis.
A small study involving 16 people with primary progressive MS investigated if the drug would have a neuroprotective effect. The results did not show any definite effect. There was a trend for a reduction in MRI changes but not in clinical measures of disability. A small study in relapsing remitting MS also failed to find an effect on brain volume.
A further study investigated the potential nerve-protecting effects of riluzole in people with clinically isolated syndrome or early MS when combined with interferon beta 1a. There was no evidence that riluzole treatment reduced brain volume loss in early MS.
Riluzole was one of three drugs studied in the MS-SMART trial, which involved 440 people with secondary progressive MS. Participants took amiloride (used to treat high blood pressure and heart disease), riluzole, fluoxetine (used for depression) or a placebo pill for two years. MRI scans and other clinical measures such as walking, eyesight and simple thinking tests were done before and after treatment to test for signs of MS disease progression. Researchers found no clinical effect of the three drugs being tested. Although the three drugs in MS-SMART were not found to be effective, the trial was valuable in helping researchers to design clinical trials which compare several treatments to placebo at the same time. It has also enhanced our understanding of the biology of progressive MS.