Ursodiol (Urisdol): Clinical Applications and Uses
Ursodiol (Urisdol) is primarily used to treat primary sclerosing cholangitis (PSC) and to dissolve certain types of gallstones, with a standard dose of 13-15 mg/kg/day that should not exceed 20 mg/kg/day due to potential adverse outcomes at higher doses. 1
Primary Indications
Primary Sclerosing Cholangitis (PSC)
- Improves abnormal liver function tests in patients with PSC
- Standard dosing: 13-15 mg/kg/day, not to exceed 20 mg/kg/day
- Does not significantly improve histology or long-term prognosis 1
- May reduce the risk of colonic cancer in PSC patients
Gallstone Dissolution
- Effective for radiolucent (cholesterol) gallstones
- Success rates of 30-80% depending on stone size and number
- Not effective for calcified or pigment stones 2
- Works by:
- Decreasing biliary cholesterol secretion
- Not inhibiting hepatic bile acid synthesis
- Resisting bacterial dehydroxylation (reducing lithocholic acid formation)
Secondary Indications
Primary Biliary Cirrhosis
- Slows disease progression in primary biliary cirrhosis
- Reduces need for liver transplantation
- Most effective when started before significant hyperbilirubinemia or cirrhosis develops 3
Prevention of Hepatic Complications in Bone Marrow Transplantation
- May reduce incidence of veno-occlusive disease (VOD) of the liver
- Particularly useful in patients receiving busulfan plus cyclophosphamide as preparative regimen
- Prophylactic use shows promise in high-risk patients 4, 5
Dosing Considerations
- Standard dosing: 13-15 mg/kg/day for PSC and primary biliary cirrhosis
- Warning: Higher doses (28-30 mg/kg/day) associated with worse outcomes despite improvement in liver function tests 1
- Available forms:
- Commercial: 300 mg capsules and 250 mg tablets
- Can be compounded as suspension (50-100 mg/mL) with 181-day stability 6
Monitoring and Safety Profile
- Excellent safety profile with minimal side effects
- Less than 1% of patients experience transient diarrhea
- Liver function tests typically remain normal during therapy 2
- Regular monitoring of liver enzymes recommended to assess response
Clinical Pearls and Pitfalls
- High-dose ursodiol (>20 mg/kg/day) should be avoided as it may lead to worse outcomes despite improvement in liver enzymes 1
- Recurrence of gallstones may occur in approximately 50% of patients within 84 months after successful dissolution
- For PSC patients, ERCP remains the procedure of choice to manage dominant biliary strictures despite ursodiol therapy
- Annual colonoscopy screening is recommended for PSC patients due to increased colorectal cancer risk 1
- In advanced liver disease with liver failure, ursodiol is not sufficient, and liver transplantation may be necessary
Patient Selection
- Best candidates for gallstone dissolution:
- Patients with radiolucent (cholesterol) stones
- Smaller and fewer stones have better dissolution rates
- Not appropriate for:
- Calcified stones
- Pigment stones
- Advanced liver failure requiring transplantation
Ursodiol represents an important therapeutic option for specific hepatobiliary conditions with an excellent safety profile when used at appropriate doses and in properly selected patients.