A 28-year-old woman with a lifelong history of easy bruising and menorrhagia presents with a platelet count of 45,000/μL and normal coagulation studies. Bone marrow examination shows increased megakaryocytes. What is the drug of choice for initial treatment of immune thrombocytopenia (ITP) in this patient?

Explanation

## First-Line Treatment of ITP **Key Point:** Corticosteroids are the gold-standard first-line pharmacological agent for immune thrombocytopenia in adults, particularly in symptomatic patients or those with platelet counts <30,000/μL. ### Mechanism of Action Corticosteroids (typically prednisolone 1 mg/kg/day) work by: 1. Suppressing autoantibody production 2. Reducing Fc-receptor-mediated platelet destruction in the spleen 3. Decreasing macrophage activation ### Response Rates and Timeline - **Response rate:** 60–80% of patients achieve platelet count >50,000/μL - **Time to response:** 3–7 days (faster than IVIG in most cases) - **Duration:** Variable; many patients relapse upon taper ### Clinical Indications for Corticosteroids - Symptomatic bleeding (mucosal, intracranial risk) - Platelet count <30,000/μL - Platelet count <50,000/μL with high bleeding risk - First-line before considering splenectomy **High-Yield:** Prednisolone is preferred over dexamethasone because it has lower mineralocorticoid activity and better long-term tolerability. ### Why Not Other Options in First-Line? | Agent | Role | Timing | |-------|------|--------| | IVIG | Rapid response needed (emergency) | Second-line or concurrent | | Rituximab | Steroid-dependent/refractory | Third-line | | Splenectomy | Steroid-responsive patients | After medical optimization | **Clinical Pearl:** In this patient with menorrhagia and symptomatic thrombocytopenia, corticosteroids offer rapid platelet recovery while avoiding the morbidity of splenectomy and the cost/availability issues of IVIG in resource-limited settings. [cite:Harrison 21e Ch 139]