Provided herein are methods for treating or ameliorating cholestatic liver disease in a subject in need thereof. The methods include administering an Apical Sodium-dependent Bile Acid Transport Inhibitor (ASBTI) to the subject. The methods include determining a genotype of the subject and predicting subject response to the ASBTI administration based upon the genotype. The methods further include determining, adjusting, or modulating a dose of the ASBTI administered to the subject based upon the genotype or upon measurements of clinically relevant disease parameters.
