What is the recommended dosage of Ursodeoxycholic Acid (UDCA) for adults?

UDCA Dosage for Adults

The recommended dosage of ursodeoxycholic acid (UDCA) for adults varies significantly by indication: 13-15 mg/kg/day for primary biliary cholangitis (PBC), 8-10 mg/kg/day for gallstone dissolution, and UDCA is NOT recommended for routine treatment of primary sclerosing cholangitis (PSC) due to lack of efficacy and potential harm at higher doses. 1, 2, 1

Primary Biliary Cholangitis (PBC)

UDCA at 13-15 mg/kg/day is the established first-line treatment for PBC and should be administered as a single bedtime dose. 3, 4

• This dosage significantly decreases serum bilirubin, alkaline phosphatase, cholesterol, and immunoglobulin M levels compared to placebo 3
• Long-term treatment at this dose delays histological progression when started at early disease stages 3
• Treatment is associated with significant reduction in likelihood of liver transplantation or death in patients with moderate to severe PBC 3
• Research suggests the optimal dose is approximately 900 mg/day (equivalent to 13.5 mg/kg/day for a 70kg adult), which produces the greatest enrichment of UDCA in serum bile acids 5

Gallstone Dissolution

For radiolucent gallbladder stones, the FDA-approved dosage is 8-10 mg/kg/day given in 2 or 3 divided doses. 2

• Bedtime administration may reduce the minimum effective dose to approximately 8.4 mg/kg/day while maintaining efficacy 6
• Treatment should continue until dissolution is confirmed on repeat ultrasound examination within 1-3 months after stones appear dissolved 2
• If partial stone dissolution is not seen by 12 months, the likelihood of success is greatly reduced 2

Gallstone Prevention During Rapid Weight Loss

The recommended dosage is 600 mg/day (300 mg twice daily) for patients undergoing rapid weight loss. 2

Primary Sclerosing Cholangitis (PSC)

UDCA is NOT recommended for routine treatment of newly diagnosed PSC. 1

Critical Dosing Considerations for PSC:

• Low-dose UDCA (10-15 mg/kg/day): Improves liver biochemistry but does not improve clinical outcomes including death, transplantation, or disease progression 1

• Moderate-dose UDCA (15-20 mg/kg/day): May be considered in select cases as it can improve serum liver tests and surrogate markers of prognosis, though available data does not support a firm recommendation 1, 3

• High-dose UDCA (28-30 mg/kg/day): MUST BE AVOIDED - associated with increased serious adverse events, higher rates of death, liver transplantation, and development of varices 1

Important Caveats for PSC:

• The 2019 British Society of Gastroenterology guidelines provide a STRONG recommendation against routine UDCA use in newly diagnosed PSC 1
• For patients already established on UDCA therapy, there is evidence of harm at doses of 28-30 mg/kg/day 1
• The 2010 American Association for the Study of Liver Diseases guidelines recommend against UDCA as medical therapy for adult PSC patients (Grade 1A recommendation) 1
• A large multicenter study of high-dose UDCA (28-30 mg/kg) was terminated early due to higher rates of serious adverse events in the treatment group 1

Intrahepatic Cholestasis of Pregnancy

The recommended dosage is 10-15 mg/kg/day divided into 2-3 doses daily. 3

• Decrease in pruritus typically occurs within 1-2 weeks 3
• Biochemical improvement is usually seen within 3-4 weeks 3
• If pruritus is not relieved, the dose can be titrated to a maximum of 21 mg/kg/day 3
• UDCA is considered safe during pregnancy and breastfeeding 3

Administration Considerations

• Bedtime dosing may be more effective than mealtime dosing for gallstone treatment, allowing for lower effective doses 6
• For PBC, single bedtime dosing of the full daily dose is recommended 4
• Long-term therapy is generally required for chronic liver diseases 7
• Maintain appropriate timing between UDCA and other medications to prevent potential absorption interactions 7

Monitoring Requirements

• Regular monitoring of liver biochemistry is essential to assess treatment response 3
• For gallstone dissolution, ultrasound images should be obtained at 6-month intervals for the first year 2
• In PBC, biochemical response should be evaluated after 1 year of therapy to identify patients at risk of progressive disease 3

Critical Safety Warning

The narrow therapeutic window between the recommended dose (13-15 mg/kg/day) and toxic dose (28-30 mg/kg/day) requires careful dosing, particularly in PSC where high doses have demonstrated clear harm. 1, 8