What is the recommended dose of Eltrombopag (thrombopoietin receptor agonist) for adults with chronic immune thrombocytopenia (ITP)?

Eltrombopag Dosing for Adults with Chronic Immune Thrombocytopenia (ITP)

The initial recommended dose of eltrombopag for adults with chronic ITP is 50 mg once daily, with subsequent adjustments based on platelet response, not exceeding 75 mg daily. 1

Initial Dosing and Special Populations

• Standard initial dose: 50 mg once daily for most adults 1
• Reduced initial dose: 25 mg once daily for patients of East or Southeast Asian descent 1
• Reduced initial dose: 25 mg once daily for patients with hepatic impairment (Child-Pugh A, B, C) 1

Administration Requirements

• Must be taken on an empty stomach (1 hour before or 2 hours after meals) 1
• This dietary restriction is important for proper absorption and consistent drug levels

Dose Adjustment Algorithm

1. Initial monitoring: Check platelet counts weekly for the first 6 weeks 1
2. Response assessment: Evaluate platelet response after 2-3 weeks of treatment 1
3. Dose escalation: If platelet count remains <50 × 10^9/L after 2-3 weeks, increase dose to 75 mg daily 1
4. Dose maintenance: Once stable response is achieved (platelet count ≥50 × 10^9/L for at least 6 months), consider gradual dose reduction 1
5. Dose reduction strategy: Decrease by 25 mg every 2 weeks while monitoring platelet counts 1

Treatment Goals and Efficacy

• Target platelet count: ≥50 × 10^9/L (not normalization) to reduce bleeding risk 1
• Response typically occurs within 1-2 weeks of starting treatment 1
• Response rates: 70-81% with doses of 50-75 mg, and up to 85-95% in long-term studies 1, 2

Long-term Maintenance Options

For patients with stable response, two maintenance approaches are possible:

1. Daily dosing: Continue with lowest effective daily dose that maintains target platelet count
2. Intermittent dosing: Some patients may maintain adequate response with reduced frequency (25 mg 2-5 days per week) 1, 3

Monitoring Requirements

• Platelet counts: Weekly until stable, then at least monthly 1
• Liver function tests: Regular monitoring due to risk of hepatotoxicity 1
• Bone marrow examination: Consider if treatment failure or new cytopenia develops (risk of reticulin formation) 1, 4

Common Pitfalls and Caveats

1. Relapse after discontinuation: Approximately 83.3% of patients may relapse after stopping eltrombopag 1
2. Hepatotoxicity risk: Monitor liver function tests regularly; 7% of patients may experience mild ALT elevations 2
3. Thromboembolic risk: Though uncommon (2% in clinical trials), use caution in patients with pre-existing thrombotic risk factors 5, 2
4. Dietary restrictions: Poor compliance with the empty stomach requirement may lead to variable drug levels and inconsistent response

Alternative Approaches

• For patients with good response but quality of life concerns due to dietary restrictions, intermittent dosing (2-4 doses weekly) may be considered 1, 3
• In a study of intermittent dosing, 71% of platelet counts were maintained ≥100 × 10^9/L with 2-4 weekly doses 3

Eltrombopag has demonstrated excellent efficacy in managing chronic ITP, with the majority of patients achieving the target platelet count on appropriate dosing. Regular monitoring and dose adjustments are essential for optimal outcomes.