Antiviral and Nausea Treatments Ease Fatigue in MS, Small Study Reports

An antiviral medication called amantadine and ondansetron, which treats chronic nausea, both work to reduce fatigue in people with multiple sclerosis (MS), but amantadine may be more effective, a single-site trial in Iran reports.

The study, “Comparison of the effects of amantadine and ondansetron in treatment of fatigue in patients with multiple sclerosis,” was published in the journal Clinical and Translational Medicine.

Fatigue is a commonly experienced by MS patients, and most anti-inflammatory MS therapies do not address this particular symptom. A need exists for other interventions — pharmacological or not — to address fatigue in these people.

Amantadine is an antiviral therapy that has been suggested for the management of fatigue, although its mechanism of action is not clear. Ondansetron is used to treat chronic nausea and vertigo, including in MS patients, the researchers said. Studies have suggested that both these therapies may be helpful with MS-related fatigue.

Researchers compared their effectiveness and safety in 53 people with MS-associated fatigue in a clinical trial (IRCT20120215009014N250). All were treated at the Imam Clinic and Sina Hospital in Hamadan from November 2018 through March.

Participants were randomly assigned to treatment with amantadine (100 mg twice daily) or ondansetron (4 mg twice daily) for four weeks. Then after a four-week pause, they resumed a four-week treatment using the other therapy. Their average age was 54, and most were female (45 patients).

Fatigue was assessed using the Fatigue Severity Scale (FSS) questionnaire; patients were also asked to self-rate their fatigue as mild, moderate, or severe before treatment and again after each therapy.

Results showed that in both treatment groups, fatigue was significantly decreased at the end of treatment compared to its start — FSS scores dropped from 43.07 to 37.36 after treatment with amantadine, and from 43.22 to 40.0 after treatment with ondansetron.

These results supported the efficacy of both in addressing fatigue in MS patients, and suggested that amantadine was slightly better than ondansetron.

More patients while on amantadine rated their fatigue as significantly less severe after four weeks than did those using ondansetron, the study noted.

“Both drugs significantly decreased the fatigue severity of patients. There was no statistically significant difference between the two regimens in terms of the mean score of fatigue before and after treatment, and the frequency of complications,” researchers wrote. “However, when ranking the severity of fatigue (mild, moderate, severe), fatigue reduction after intervention in the amantadine group was significantly higher than ondansetron.”

No side effects were reported in either treatment group.

Researchers emphasized that additional studies are needed to validate these findings, and to determine exactly how these medications work to ease fatigue in MS.