What are the indications and dosages for Ursodeoxycholic acid (UDCA)?

Indications and Dosages for Ursodeoxycholic Acid (UDCA)

Ursodeoxycholic acid is primarily indicated for the treatment of primary biliary cirrhosis (PBC), dissolution of small radiolucent gallstones, and prevention of gallstone formation in obese patients experiencing rapid weight loss. 1

Primary Biliary Cirrhosis (PBC)

• Dosage: 13-15 mg/kg/day 1, 2, 3
• This dose has been shown to be the most effective in improving liver biochemistry and prolonging survival 2
• Studies comparing different dosages found that 13-15 mg/kg/day was superior to lower doses (5-7 mg/kg/day) and showed no additional benefit with higher doses (23-25 mg/kg/day) 3
• Should be continued long-term as it improves survival 1

Gallstone Dissolution

• Dosage: 8-10 mg/kg/day divided into 2 or 3 doses 4
• Indicated for patients with radiolucent, noncalcified gallstones <20 mm in greatest diameter 4
• Most appropriate for patients with increased surgical risk or those who refuse surgery 4
• Monitoring: Ultrasound images should be obtained at 6-month intervals for the first year to monitor response 4
• Treatment duration: Safety beyond 24 months is not established 4
• Efficacy is approximately 10-12 mg/kg/day 1, 5

Gallstone Prevention

• Dosage: 600 mg/day (300 mg twice daily) 4
• Indicated specifically for obese patients experiencing rapid weight loss 4

Primary Sclerosing Cholangitis (PSC)

• Not recommended for routine treatment of newly diagnosed PSC 6
• Low-to-medium doses (10-15 mg/kg/day) may improve liver biochemistry but not disease progression 6
• High doses (28-30 mg/kg/day) may be harmful in late-stage disease 6
• Exception: May be considered in PSC patients with overlap syndrome (PSC with autoimmune hepatitis features) 1

Other Indications with Limited Evidence

• ABCB4 deficiency: Low-to-medium dose (10-15 mg/kg/day) can be given, but evidence is limited 6
• Sclerosing cholangitis in critically ill patients (SC-CIP): Low-to-medium dose (10-15 mg/kg/day) can be considered 6
• Intrahepatic cholestasis of pregnancy: UDCA is considered safe during pregnancy 6
• Cholestasis-associated pruritus in pregnancy: Start with low dose (10 mg/kg/day) and slowly increase to 20 mg/kg/day 6

Important Considerations

1. Monitoring:

   • Regular assessment of liver function tests is recommended 1
   • For gallstone dissolution, ultrasound follow-up at 6-month intervals 4

2. Treatment Duration:

   • For PBC: Long-term/indefinite treatment
   • For gallstone dissolution: Until confirmed dissolution (safety beyond 24 months not established) 4

3. Precautions:

   • When using with anion exchange resins (cholestyramine), administer at least 4 hours apart 6
   • High doses (28-30 mg/kg/day) may be harmful in late-stage PSC 6

4. Pregnancy Considerations:

   • Medium-dose UDCA is considered safe during pregnancy and breastfeeding 6
   • For cholestasis-associated pruritus in pregnancy, start with low dose and gradually increase 6

Efficacy Expectations

• In PBC: Improves liver biochemistry and may prolong survival 7
• In gallstone dissolution: Most patients who achieve complete dissolution will show partial or complete dissolution at first re-evaluation (6 months) 4
• If partial dissolution is not seen by 12 months, likelihood of success is greatly reduced 4