Ursodeoxycholic Acid (UDCA) is a hydrophilic, tertiary bile acid used primarily as a hepatoprotective and choleretic agent. It is the standard pharmacological therapy for primary biliary cholangitis (PBC) and is widely used for gallstone dissolution and various cholestatic liver conditions. In the Indian context, it is a first-line treatment for PBC and is extensively prescribed for symptomatic gallstones in patients unfit for surgery.
Adult: PBC & PSC: 13-15 mg/kg/day in 2-4 divided doses with meals. For a 70kg adult, ~900-1050 mg/day. Gallstone dissolution: 8-10 mg/kg/day in 2-3 divided doses, usually at bedtime. The 450mg strength is convenient for these regimens (e.g., 2 tablets/day for dissolution, 2-3 tablets/day for PBC).
Note: Take with meals to improve tolerance and ensure consistent absorption. For gallstone dissolution, the evening dose is critical. Tablets should be swallowed whole with a glass of water. Do not crush or chew. Therapy for gallstones requires confirmation of stone dissolution via ultrasound every 6 months.
UDCA exerts multiple hepatoprotective and choleretic effects. 1) It replaces endogenous, hydrophobic, cytotoxic bile acids (like chenodeoxycholic and deoxycholic acid) in the bile acid pool, reducing their detergent injury to hepatocyte membranes and bile duct epithelial cells. 2) It stimulates hepatobiliary secretion, inducing a bicarbonate-rich hypercholeresis, which improves bile flow and protects cholangiocytes. 3) In cholestasis, it activates alternative excretory pathways. 4) It has anti-apoptotic, membrane-stabilizing, and immunomodulatory properties.
Pregnancy: Pregnancy Category B (US FDA). Animal studies show no risk, but human data is limited. Used for cholestasis of pregnancy. Use only if potential benefit justifies potential risk. Monitor LFTs closely.
Driving: No known effects on driving ability. Dizziness has been reported rarely.
| Cholestyramine, Colestipol, Colesevelam | Markedly reduce absorption of UDCA by binding it in the intestine. Efficacy is lost. | Major |
| Aluminium-based Antacids | May reduce absorption. Separate administration by at least 2 hours. | Moderate |
| Oral Contraceptives, Estrogens | May counteract UDCA's effect on bile cholesterol saturation, reducing gallstone dissolution efficacy. | Moderate |
| Ciclosporin (Cyclosporine) | UDCA may increase the absorption of ciclosporin, potentially raising its blood levels. Monitor ciclosporin levels. | Moderate |
| Clofibrate, Fibrates | Increase biliary cholesterol secretion, potentially counteracting UDCA in gallstone therapy. | Moderate |
| Rosuvastatin, Atorvastatin | No major interaction. Often used concomitantly in PBC for lipid management. | Minor |