Amantadine is beneficial in restless legs syndrome

Twenty-one patients (mean age 70 yrs) with restless legs syndrome (RLS) were treated with amantadine in an open-label trial. Amantadine was started at 100 mg per day and was increased every 3-5 days by 100 mg (up to a maximum of 300 mg per day) until significant relief of symptoms or intolerable side effects were experienced. Patients were rated pre- and posttreatment using an RLS rating scale (0-10). Each patient also rated the degree of response in a continuous scale from 0% (no improvement) to 100% (complete improvement). Eleven of 21 (52%) had subjective benefit to amantadine, with degree of response ranging from 25%-100% (mean 69%) among responders. Six had 95%-100% improvement. The RLS score for all 21 patients dropped from a mean (+/- standard deviation) of 9.8 +/- 0.6 (range, 8-10) pretreatment to 6.6 +/- 3.8 (range, 0-10) posttreatment (p = 0.001). The duration of response was 0-13 months (mean, 3.6 +/- 4.5), with nine responders still remaining on the drug as of last follow up. The mean effective dose was 227 mg per day. The most common side effects were drowsiness (3), fatigue (2), and insomnia (2); only two stopped amantadine because of side effects. We conclude that amantadine is an effective and well-tolerated drug for RLS.