Weight-Based Dosing of Ursodeoxycholic Acid (UDCA)
The recommended weight-based dosing of UDCA is 13-15 mg/kg/day for primary biliary cholangitis (PBC), which represents the established first-line treatment with the strongest evidence base. 1, 2
Disease-Specific Dosing Recommendations
Primary Biliary Cholangitis (PBC)
- Standard dose: 13-15 mg/kg/day - This is the established treatment of choice supported by multiple placebo-controlled trials and long-term case-control studies 1, 2
- This dosing significantly decreases serum bilirubin, alkaline phosphatase, cholesterol, and immunoglobulin M levels 1
- Long-term treatment at this dose delays histological progression when started at early disease stages and reduces likelihood of liver transplantation or death 1, 2
- Research suggests 900 mg/day (approximately 13.5 mg/kg/day for a 67 kg patient) produces optimal enrichment of UDCA in serum bile acids 3
Primary Sclerosing Cholangitis (PSC)
- Conditional dose: 15-20 mg/kg/day - May improve serum liver tests and surrogate markers of prognosis, though evidence is weak 4, 1
- Critical warning: DO NOT use 28-30 mg/kg/day - This high dose is associated with enhanced risk of liver transplantation and development of varices in advanced disease 1, 5
- The American Association for the Study of Liver Diseases does not support routine use of UDCA for PSC due to limited efficacy and potential harm at high doses 1, 5
- Biliary enrichment of UDCA reaches a plateau at 22-25 mg/kg, with no increase in toxic hydrophobic bile acids at these doses 6
Intrahepatic Cholestasis of Pregnancy (ICP)
- Initial dose: 10-15 mg/kg/day divided into 2-3 doses 1, 2
- If pruritus is not relieved, the dose can be titrated to a maximum of 21 mg/kg/day 1
- Decrease in pruritus typically occurs within 1-2 weeks, with biochemical improvement within 3-4 weeks 1
ABCB4 Deficiency and SC-CIP
- Low-to-medium dose: 10-15 mg/kg/day - Provides anticholestatic and anti-inflammatory effects while stimulating biliary bicarbonate secretion 4, 1
- Evidence is limited but supports use for small duct sclerosing cholangitis and hepatolithiasis associated with ABCB4 deficiency 4
Important Clinical Considerations
Dosing Pitfalls to Avoid
- Never exceed 25 mg/kg/day in PSC - Doses of 28-30 mg/kg/day have demonstrated harm, particularly in late-stage disease with increased mortality and need for transplantation 4, 5
- The difference between recommended (13 mg/kg/day) and toxic dose (28 mg/kg/day) is narrow 7
- For non-responders to standard PBC dosing, increasing to 18-22 mg/kg/day may be considered before second-line therapy, with response rates of 59.4% at 6 months versus 36.1% with standard dosing 8
Monitoring Requirements
- Regular monitoring of liver biochemistry is essential to assess treatment response 1, 2
- In PBC, AMA-positive individuals with normal liver tests require annual reassessment of biochemical markers 1, 2
- In ICP, serum bile acids should be checked at least weekly as they may continue to rise with advancing gestation 2
Safety Profile
- UDCA is generally well tolerated at recommended doses 1
- Side effects may include mild diarrhea, nausea, vomiting, and rash, which are typically tolerable 8
- UDCA is considered safe during pregnancy and breastfeeding 1