obeticholic acid + ursodeoxycholic acid

A fixed (or co-administered) combination of **obeticholic acid** and **ursodeoxycholic acid**, two pharmacologically distinct bile acid-related agents, used for the treatment of **primary biliary cholangitis (PBC)** in patients who have an inadequate response to ursodeoxycholic acid alone[1][2][3][6]. Obeticholic acid is a **synthetic bile acid analog** and a potent agonist of the farnesoid X receptor (FXR), which helps regulate bile acid synthesis, reduce hepatic bile acid load, and decrease inflammation and fibrosis[2][6]. Ursodeoxycholic acid is a **hydrophilic bile acid** with cytoprotective, choleretic, immunomodulating, and anti-apoptotic properties, facilitating bile flow, protecting hepatocytes and cholangiocytes, and reducing cholesterol saturation of bile[4][6]. The combination addresses different mechanisms and provides additive improvement in selected liver function tests in PBC patients compared to monotherapy.