Amantadine (Symmetrel) for fatigue in multiple sclerosis

Amantadine belongs to a class of drugs known as antivirals, used to prevent or treat influenza (flu) infections. This antiviral drug has also shown activity against viruses that belong to the Flaviviridae family of viruses, to which hepatitis C virus belongs. It has been used for many years as a drug of choice in combating fatigue and has been used to treat fatigue in patients with multiple sclerosis (MS). It works by facilitating the release of dopamine (i.e., a nervous system hormone) from nerve cells. Amantadine is also used in Parkinson’s disease.

Since this drug has an antiviral action, and MS exacerbations are triggered by infections, experts suggest that the use of amantadine can reduce the amount of flare-ups by preventing viral infections. In a two-year study, fewer exacerbations resulted in those treated with amantadine versus placebo. Intermittent therapy is suggested due to the diminished effects of the drug after a few months. Caution should be taken by patients with kidney disease to prevent toxicity. It is usually well tolerated, but side effects of amantadine include insomnia, mood disturbances, allergic reactions, confusion, and hallucinations.