I have erectile dysfunction and I can't honestly say whether or not Mexiletine is the problem or not. You need to have your testosterone levels checked by your doctor to see what is going on. My T levels were extremely low and I am on testosterone replacement therapy. I also have to use the tri-mix compound shots to obtain an erection that will last. The shots work very well. If you have continuing problems, you can ask your doctor about those. Best Regards, Staurt

Type of Myotonia: Thomsens

Country: USA