18. Treatment with anti-myotonia medication within 30 days prior to screening. May include, but not be limited to: Phenytoin, Carbamazepine, Procainamide, Disopyramide, Nifedipine, Acetazolamide, Clomipramine, Imipramine, Amytriptiline, Taurine, Quinine, Mexiletine