Ursodeoxycholic acid

Ursodeoxycholic acid (UDCA), also known as ursodiol, is a bile acid produced by the liver and used in the treatment of gallstones and liver disease. It is a secondary bile acid, which means it is not produced directly by the liver but is instead formed in the intestine from chenodeoxycholic acid.

Chemistry

Ursodeoxycholic acid is a cholanic acid with a structure similar to that of cholic acid. It has a hydroxyl group at the 3, 7, and 24 positions. The presence of these hydroxyl groups makes the molecule more hydrophilic (water-loving) than other bile acids, which contributes to its therapeutic effects.

Pharmacology

Ursodeoxycholic acid works by increasing the concentration of bile acids in the liver and suppressing the synthesis of cholesterol. This leads to a decrease in the amount of cholesterol in bile, which can help dissolve cholesterol gallstones. In addition, ursodeoxycholic acid has anti-inflammatory and immunomodulatory effects, which can be beneficial in the treatment of certain liver diseases.

Clinical uses

Ursodeoxycholic acid is used in the treatment of several conditions, including:

• Gallstones: Ursodeoxycholic acid can help dissolve small, non-calcified gallstones in patients who are not good candidates for gallbladder surgery.
• Primary biliary cholangitis: This is a chronic liver disease in which the bile ducts in the liver are slowly destroyed. Ursodeoxycholic acid can help slow the progression of this disease.
• Primary sclerosing cholangitis: Although the evidence is less clear, some studies suggest that ursodeoxycholic acid may also be beneficial in this condition.

Side effects

The most common side effects of ursodeoxycholic acid are diarrhea and abdominal pain. Less common side effects include nausea, vomiting, constipation, and skin rash. In rare cases, ursodeoxycholic acid can cause liver damage or pancreatitis.

See also

• Bile acid
• Gallstones
• Liver disease