List of products in the National Drug Code with proprietary name . Miglustat is used for the long-term treatment of a certain rare genetic problem (Gaucher's disease). It works by decreasing the amount of a certain natural fatty substance (glucosylceramide) that builds up due to this condition. This can help improve symptoms of Gaucher's disease, such as tiredness, pain in the joints/bones, and a swollen liver or spleen.