Amifampridine-d3 2HCl is a deuterated compound of Amifampridine 2HCl. Amifampridine 2HCl has a CAS number of 54-96-6. Amifampridine is predominantly in the treatment of a number of rare muscle diseases. Amifampridine works by blocking potassium channel efflux in nerve terminals so that action potential duration is increased. Ca2+ channels can then be open for a longer time and allow greater acetylcholine release to stimulate muscle at the end plate.