The World Health Organization's ATC classification organizes medical drugs based on therapeutic properties, chemical composition, and anatomy. It helps make essential medicines readily available globally and is widely used in the pharmaceutical industry.
Exogenous chenodeoxycholic acid is used as replacement therapy to restore the feedback inhibition lost due to the deficiency/absence of endogenous chenodeoxycholic acid. In CTX, deficiency of chenodeoxycholic acid causes a lack of feedback of cholesterol 7 alpha hydroxylase (CYP7A1) and HMG CoA reductase, causing increased production of atypical bile acids, bile alcohols and cholestanol that lead to the pathological consequences of the condition.