UDCA Dosing for Gallstone Dissolution in a 30kg Patient
For gallstone dissolution in this 30kg woman with a 0.5cm stone, administer UDCA at 8-10 mg/kg/day divided into 2-3 doses daily, which equals 240-300 mg total daily dose. 1
Specific Dosing Calculation
- Total daily dose: 240-300 mg/day (based on 8-10 mg/kg/day for 30kg body weight) 1
- Divided dosing: Split into 2 or 3 doses throughout the day 1
- Example regimen: 100 mg three times daily OR 150 mg twice daily 1
Stone Characteristics Favoring Success
This patient has favorable characteristics for dissolution therapy:
- Stone size: 0.5 cm is considered small, which predicts better dissolution rates 2, 3
- Optimal candidates: Radiolucent (cholesterol) stones that are small in size respond best 1, 2
- Success rates: 30-80% dissolution occurs with appropriately selected radiolucent stones, with higher success in smaller stones 4, 5
Monitoring Protocol
Initial assessment requirements before starting therapy:
- Confirm gallbladder visualization on oral cholecystogram (functioning gallbladder required) 1, 2
- Verify stone is radiolucent on plain abdominal film 1, 2
- Obtain baseline liver function tests 2
- Perform ultrasound evaluation of gallbladder and biliary tree 2
Follow-up monitoring schedule:
- Ultrasound imaging at 6-month intervals during the first year 1
- If partial dissolution not seen by 12 months, likelihood of success is greatly reduced and therapy should be reconsidered 1
- Once stones appear dissolved, continue UDCA and confirm dissolution on repeat ultrasound within 1-3 months 1
Treatment Duration and Expectations
- Expected duration: 1-2 years for most patients achieving complete dissolution 5
- Early response: Most successful patients show partial or complete dissolution at first 6-month evaluation 1
- Symptom relief: Biliary symptoms typically disappear within 3 months of starting therapy 3
Important Contraindications
Do not use UDCA if:
- Patient is pregnant or likely to become pregnant 2
- Severe acute or chronic intrahepatic cholestasis present 2
- Acute cholestasis or common bile duct obstruction exists 2
- Gallbladder is non-functioning (non-visualizing on oral cholecystogram) 1, 2
- Stones are calcified or pigmented 4
Safety Profile
- Side effects: Less than 1% experience transient diarrhea that does not require discontinuation 4
- Liver function: Remains normal during therapy 4, 3
- Biliary lithocholic acid: Does not increase during treatment 3
- Long-term safety: UDCA has a favorable safety profile with minimal toxicity 2, 5
Critical Pitfall: Stone Recurrence
- Recurrence rate: Approximately 50% of patients experience stone recurrence within 84 months after successful dissolution 4
- Management: Recurrent stones can be retreated with UDCA 4
- Prevention consideration: This high recurrence rate should be discussed with the patient when weighing medical dissolution versus surgical options 4