Zavesca is used to treat adults with mild to moderate type I Gaucher disease. Zavesca is only used in patients who cannot be treated with enzyme replacement therapy. Zavesca has not been studied in children under 18 years of age.

Type I Gaucher disease is an inherited disease that you get from both your parents. People with Type I Gaucher disease are missing an enzyme that breaks down a chemical in the body called glucosylceramide. Too much glucosylceramide causes liver and spleen enlargement, changes in the blood, and bone disease. Zavesca may stop glucosylceramide from forming.