A 32-year-old woman presents with a 6-month history of menorrhagia and spontaneous bruising. Laboratory investigations reveal platelet count 18,000/μL, normal PT and aPTT, and negative direct antiglobulin test. Bone marrow shows increased megakaryocytes. What is the drug of choice for initial treatment of immune thrombocytopenia (ITP) in this patient?

Explanation

## First-Line Treatment of Immune Thrombocytopenia ### Clinical Presentation This patient has ITP with: - Severe thrombocytopenia (18,000/μL) - Mucocutaneous bleeding (menorrhagia, bruising) - Normal coagulation studies - Increased megakaryocytes on bone marrow (appropriate response to immune destruction) ### Drug of Choice: Prednisolone **Key Point:** Corticosteroids (prednisolone 1 mg/kg/day) are the first-line pharmacological treatment for newly diagnosed ITP with bleeding symptoms. **High-Yield:** Mechanism of action includes: 1. Reduction of antiplatelet antibody production 2. Decreased Fc receptor-mediated platelet destruction in the spleen 3. Immunosuppression via T-cell inhibition **Clinical Pearl:** Response rate to corticosteroids is 60–80% in newly diagnosed ITP, with platelet counts typically rising within 3–7 days. ### Comparative Treatment Approach | Treatment | Indication | Onset | Duration | Role | |-----------|-----------|-------|----------|------| | **Prednisolone** | First-line, symptomatic | 3–7 days | Variable | Initial therapy | | IVIG | Emergency (life-threatening bleed), pregnancy | Hours | 3–4 weeks | Adjunct or emergency | | Splenectomy | Steroid-dependent/refractory | N/A | Long-term | Second-line | | Rituximab | Steroid-refractory | Weeks | Variable | Third-line | **Tip:** In this case, the patient has moderate-to-severe symptomatic ITP (menorrhagia + spontaneous bruising) but no life-threatening hemorrhage (e.g., ICH, GI bleed). Prednisolone is safer, faster to initiate, and has the highest response rate as first-line therapy. ### Why Not IVIG? IVIG is reserved for: - Emergency situations (intracranial hemorrhage, severe GI bleed) - Pregnancy (preferred over corticosteroids) - Patients who cannot tolerate corticosteroids - Rapid platelet increment needed within hours In stable symptomatic ITP, IVIG is too expensive and short-acting to be first-line. ### Why Not Splenectomy or Rituximab? These are second- and third-line therapies for steroid-refractory or steroid-dependent disease, not initial treatment. [cite:Harrison 21e Ch 173]