What is the recommended dose of ursodeoxycholic acid (ursodiol) for an 18-month-old child with a liver condition?

Ursodeoxycholic Acid Dosing in an 18-Month-Old Child

For an 18-month-old child with cholestatic liver disease, the recommended dose of ursodeoxycholic acid is 15-20 mg/kg/day, divided into 2-3 doses daily. 1, 2

Dosing Algorithm by Indication

For Intrahepatic Cholestasis (Most Common Pediatric Indication)

• Standard dose: 15-20 mg/kg/day divided into 2-3 doses 1, 2
• This dosing has been specifically studied and validated in pediatric populations as young as 1.5 months 1
• Clinical improvement typically occurs within weeks, with biochemical improvements seen within 3 months 1

For Specific Cholestatic Conditions

FIC1 Disease (PFIC-1) or BSEP Disease:

• Start with ursodeoxycholic acid at standard pediatric dosing (15-20 mg/kg/day) 3
• Monitor response over 3-6 months 3
• If inadequate response, consider partial external biliary diversion (PEBD) or ileal exclusion before disease progresses to cirrhosis 3
• Critical caveat: Approximately 30% of FIC1 patients respond adequately to UDCA alone, allowing delay or avoidance of surgical interventions 3

MDR3 Disease:

• Use 10-15 mg/kg/day as initial therapy 4
• If no response after adequate trial, evaluate for liver transplantation 3

Practical Administration Guidelines

Dosing Schedule

• Divide total daily dose into 2-3 administrations throughout the day 3, 1
• Can be given with or without food, though consistency is important
• For an average 18-month-old (10-12 kg), this translates to approximately 150-240 mg total daily dose

Monitoring Parameters

• Baseline assessment: ALT, AST, alkaline phosphatase, GGT, total and conjugated bilirubin, cholesterol, pruritus severity 1, 2
• Follow-up testing: Every 3 months during first year 1
• Expected response timeline:
  • Pruritus improvement: Within 2-4 weeks 1
  • Biochemical improvement: Within 3 months 1
  • If no improvement by 6-12 months, reassess diagnosis and consider alternative interventions 3

Safety Considerations

Tolerability in Young Children

• UDCA is safe and well-tolerated in children as young as 1.5 months 1
• No significant adverse effects reported in pediatric studies at standard doses 1, 2
• Mild side effects (diarrhea, nausea) are rare and generally well-tolerated 5

Critical Warnings

• Never use high doses (>20 mg/kg/day) in children, as this has not been adequately studied in pediatrics and high doses (28-30 mg/kg/day) are contraindicated in adults with PSC due to worse outcomes 3, 4
• Do not abruptly discontinue once started, as this can cause rapid biochemical deterioration and return of symptoms 6

When UDCA Alone Is Insufficient

Poor Response Indicators

• No improvement in ALT/AST by 6 months 2
• Persistent or worsening pruritus despite 3 months of therapy 2
• Progressive cholestasis on biochemical monitoring 3

Next Steps for Non-Responders

• For FIC1/BSEP disease: Consider PEBD or ileal exclusion if performed before cirrhosis develops 3
• For MDR3 disease: Evaluate for liver transplantation 3
• For unclear etiology: Repeat liver biopsy and consider alternative diagnoses 3

Common Pitfalls to Avoid

• Underdosing: Using adult gallstone dissolution doses (8-10 mg/kg/day) instead of appropriate cholestasis doses (15-20 mg/kg/day) 7, 1
• Premature discontinuation: Stopping therapy before adequate trial period (minimum 6-12 months) 1, 2
• Inadequate monitoring: Failing to assess response at 3-6 month intervals 1
• Missing surgical window: Delaying PEBD/ileal exclusion in FIC1/BSEP patients until cirrhosis develops, when these procedures are less effective 3