Ursodeoxycholic Acid (UDCA) is a hydrophilic, tertiary bile acid used primarily as a hepatoprotective and choleretic agent. It is the standard first-line pharmacological therapy for the dissolution of cholesterol gallstones in a functioning gallbladder and for the treatment of primary biliary cholangitis (PBC). In the Indian context, it is widely prescribed for various cholestatic liver disorders, fatty liver disease, and drug-induced hepatotoxicity.
Adult: Gallstone dissolution: 8-12 mg/kg/day in 2-3 divided doses, usually with meals. For a 600mg tablet, typical dose is one tablet twice daily (approx. 10 mg/kg for a 60kg patient). PBC: 13-15 mg/kg/day in 2-4 divided doses. Maximum recommended dose is 15 mg/kg/day.
Note: Take with food to enhance absorption and reduce gastrointestinal upset. Swallow the tablet whole with a glass of water. Do not crush or chew. For gallstone therapy, bedtime dose is particularly important. Therapy duration for gallstones should be continued for 3-4 months after stone dissolution is confirmed via ultrasound.
UDCA exerts multiple hepatoprotective and choleretic effects. 1) It replaces endogenous, hydrophobic, detergent-like bile acids (like chenodeoxycholic and deoxycholic acid) in the bile acid pool with its own hydrophilic, non-cytotoxic properties, reducing their damaging effects on hepatocyte and biliary epithelial cell membranes. 2) It stimulates hepatobiliary secretion, inducing a bicarbonate-rich hypercholeresis, which improves bile flow and protects cholangiocytes. 3) It promotes the dissolution of cholesterol-rich gallstones by reducing cholesterol secretion into bile and dissolving cholesterol from the stone surface. 4) It exerts anti-apoptotic, immunomodulatory, and anti-inflammatory effects.
Pregnancy: Pregnancy Category B (US FDA). Animal studies show no risk, but adequate human studies are lacking. Used safely in the second and third trimesters for cholestasis of pregnancy. Use in the first trimester only if clearly needed. Benefits of treating PBC or severe cholestasis may outweigh risks.
Driving: UDCA has no known influence on the ability to drive and use machines. Dizziness and fatigue are rare side effects.
| Cholestyramine, Colestipol, Colesevelam | Bile acid sequestrants bind UDCA in the gut, severely reducing its absorption and efficacy. | Major |
| Aluminum-based Antacids | May reduce absorption of UDCA. | Moderate |
| Ciclosporin (Cyclosporine) | UDCA may increase the absorption of ciclosporin, potentially increasing its blood levels and risk of toxicity. | Moderate |
| Oral Contraceptives, Estrogens | May counteract the cholesterol-desaturating effect of UDCA on bile, reducing gallstone dissolution efficacy. | Moderate |
| Clofibrate, Fibrates | May increase biliary cholesterol secretion, antagonizing UDCA's effect on gallstone dissolution. | Moderate |
| Dapsone | UDCA may increase absorption of dapsone. | Moderate |
| Nitrendipine | UDCA may increase bioavailability of nitrendipine. | Minor |