Lamotrigine, a drug commonly used to treat epilepsy and certain mood disorders, has been shown to be an excellent treatment option for a rare genetic neuromuscular disease known as non-dystrophic myotonia, in a world-first trial. The study detailed the "head-to-head" trial implemented by the researchers to test two drugs, mexiletine and lamotrigine, on people with the condition. Patients were randomly assigned to receive either mexiletine for eight weeks followed by lamotrigine for eight weeks, or the reverse order, with a seven-day break in between treatments. Neither the participants nor the researchers knew which treatment was being given at any time....