Lamotrigine, Mexiletine Show Similar Benefits for Nondystrophic Myotonias

WEDNESDAY, Oct. 9, 2024 (HealthDay News) -- Improvements in nondystrophic myotonias symptoms are similar for lamotrigine and mexiletine, according to a study published in the October issue of The Lancet Neurology.

Vinojini Vivekanandam, Ph.D., from the Centre for Neuromuscular Disorders at the National Hospital for Neurology and Neurosurgery in London, and colleagues randomly assigned 53 adults with genetically confirmed symptomatic nondystrophic myotonia to receive either mexiletine for eight weeks followed by lamotrigine for eight weeks or lamotrigine followed by mexiletine with a seven-day washout period in between.

The researchers found that the mean interactive voice response stiffness score after treatment with mexiletine was 2.54 versus 2.77 with lamotrigine (mean mexiletine-lamotrigine difference, −0.23; 95 percent confidence interval, −0.63 to 0.17). For both groups, the most common adverse event was indigestion-reflux (eight participants, 208 participant-days receiving mexiletine; seven participants, 130 participant-days receiving lamotrigine). There were no serious adverse events.

"Approximately one in 17 people in the U.K. have a rare disease and the majority have no treatment. Many are neurological diseases and rarity makes clinical trials to develop treatments very difficult," Vivekanandam said in a statement. "The trial results are very exciting and important for patients with this muscle channelopathy."

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