The antidepressant fluoxetine, the active ingredient in Eli Lilly’s off-patent Prozac, may help to curb disease activity in the relapsing remitting form of multiple sclerosis, according to preliminary research from a new study.

Researchers from the University Medical Center in Groeningen, the Netherlands who carried out the study, which is published in the Journal of Neurology Neurosurgery and Psychiatry, randomly allocated 40 patients with the relapsing remitting form of MS to treatment with either 20 mg daily of fluoxetine or placebo for 24 weeks. Brain scans every four weeks were used to check the 38 patients who completed the trial for new areas of neurological inflammation, a hallmark of active disease, which showed that those in the placebo group had more new areas of inflammation than those treated with Prozac.

Also the study noted that during the last 16 weeks of treatment, almost two-thirds of patients (63%) in the group given fluoxetine had no new areas of inflammation compared with only one in four (26%) in the group given placebo.

The authors acknowledge that their study was too small before any firm conclusions could be drawn but they conclude that their results are “sufficiently encouraging to justify further studies with fluoxetine in patients with MS”. They added that higher doses and treatment combinations with other drugs that alter the immune response, should be considered.