Miglustat is primarily used in the treatment of type 1 Gaucher disease, a rare genetic disorder. It works by inhibiting the enzyme responsible for the production of glucosylceramide, thereby reducing the accumulation of this substance in the body. This helps to alleviate symptoms such as enlarged spleen and liver, bone abnormalities, and blood disorders. Miglustat is particularly beneficial for patients who cannot undergo enzyme replacement therapy. Additionally, it has shown potential in treating Niemann-Pick disease type C, another rare genetic condition, by similar mechanisms. Its ability to cross the blood-brain barrier makes it effective in addressing neurological symptoms associated with these disorders.