Ursodeoxycholic Acid is a naturally occurring bile acid. It is used for the treatment of some liver conditions. This may include diseases such as biliary Artesia (blockage of the bile duct) and cholestasis of cystic fibrosis (occurs when bile flow is restricted). It is also used in the treatment of gallstones.

Indications:
It is a biliary composition and flow-altering drug occurring naturally in mammals, and is sometimes known as a bile acid.
● It is used to reduce the cholesterol content of biliary fluid (produced by the liver and stored in the gall bladder for secretion into the intestine to digest fats).
● In general this drug is used to dissolve gallstones made of cholesterol and to treat a condition called primary biliary cirrhosis (in which the bile ducts are damaged, causing bile to accumulate in the liver, which is then damaged itself).
● Benefits of being on this drug in patients with primary biliary cirrhosis include the prevention or treatment of lack of bile flow from the liver to the intestine (cholestasis), and the dissolving of gallstones in patients who have this problem.

Usage:
● Treatment of primary biliary cirrhosis
● Dissolving gallstones that are radiolucent (they do not show up on X-rays) that are in patients with a functioning gallbladder.

Drug Interactions:
This drug should not be used with the following medications because very serious, possibly fatal interactions may occur:
● Immunosuppressant’s (cyclosporine)
● Antacids, used to treat stomach problems
● Oral contraceptives (estrogens)
● Lipid-regulating drugs (colestipol and colestyramine).

Mechanism of Action:
Ursodeoxycholic acid (UDCA) is used in the treatment of cholestatic liver diseases, gallstone dissolution, and for patients with hepatitis C virus infection to ameliorate elevated alanine aminotransferase levels. The efficacy of UDCA treatment has been debated and the mechanisms of action in humans have still not defined. Suggested mechanisms include the improvement of bile acid transport and/or detoxification, cytoprotection, and anti-apoptotic effects.

Pharmacology:
Ursodeoxycholic acid 1 is the 7[beta]-hydroxy epimer of chenodeoxycholic acid and is normally present in only trace amounts in the bile. Oral administration of pharmacological doses markedly decreases biliary cholesterol saturation.
Complete or partial dissolution of radiolucent gallstones located in a functioning gallbladder occurred in about 40 to 55% of patients treated with ursodeoxycholic acid in controlled studies of 6 months duration.

Pharmacokinetics:
Ursodeoxycholic acid suppresses hepatic synthesis and secretion of cholesterol and also inhibits intestinal absorption of cholesterol.
Absorption: Rapidly and completely absorbed from the GI tract.
Distribution: Protein binding: 96-98%. Undergoes enterohepatic recycling.
Metabolism: Partly conjugated in the liver before being excreted into the bile. Free and conjugated forms undergo 7a-dehydroxylation to lithocholic acid under the influence of gut bactera. Some are reabsorbed and then further conjugated and sulfated by the liver.
Excretion: Faeces.

Side Effects:
Feeling sick (nausea), Vomiting, Diarrhea, Gallstone calcification (calcium deposits form in the gallstone),Itching.

Contraindications:
Ursodeoxycholic acid should be used with caution in: women who are likely to become pregnant or who are breastfeeding. It should not be used in: women who are pregnant, patients with a gall bladder that is not working properly, or who have gallstones which contain calcium (i.e. are opaque on an X-ray), have severe liver problems, stomach ulcers or inflammation of the bowel.

Storage:
Store at room temperature, 15-30° C (59-86°F). Keep away from moisture.