What are the treatment options for Immune Thrombocytopenic Purpura (ITP)?

Treatment Options for Immune Thrombocytopenic Purpura (ITP)

Corticosteroids are the recommended first-line therapy for ITP, followed by splenectomy for those who fail corticosteroid therapy, and thrombopoietin receptor agonists for patients who relapse after splenectomy or have contraindications to splenectomy. 1

First-Line Treatment Options

Corticosteroids

• Prednisone: 0.5-2 mg/kg/day until platelet count increases (70-80% initial response rate)
  • Should be rapidly tapered and stopped within 4 weeks to avoid complications 1
• Dexamethasone: 40 mg/day for 4 days (up to 90% initial response rate)
  • May be more effective than standard prednisone regimens 1
• Methylprednisolone: 30 mg/kg/day for 7 days (up to 95% response rate)
  • Faster response compared to prednisone 1

Emergency/Rapid Response Options

• Intravenous Immunoglobulin (IVIg):

  • Dose: 1 g/kg as one-time dose (can be repeated if necessary)
  • Response rate: Up to 80% 2, 1
  • Faster response than corticosteroids but shorter duration 2
  • Side effects: Headaches, renal failure, thrombosis 2

• Anti-D Immunoglobulin:

  • Dose: 50-75 μg/kg
  • Only for Rh(D)-positive, non-splenectomized patients 2, 1
  • Side effects: Mild extravascular hemolysis common 2

Second-Line Treatment Options

Splenectomy

• Recommended for patients who have failed corticosteroid therapy 2
• Both laparoscopic and open splenectomy offer similar efficacy 2
• Approximately two-thirds of patients achieve normal platelet counts initially 1
• No further treatment needed in asymptomatic patients who maintain platelet counts >30 × 10⁹/L 2

Thrombopoietin Receptor Agonists

• Romiplostim (Nplate):
  • Recommended for patients who relapse after splenectomy or have contraindications to splenectomy 2, 1
  • May be considered for patients at risk of bleeding who have failed one line of therapy 2
  • Clinical trials showed 61% durable platelet response in non-splenectomized patients and 38% in splenectomized patients 3
  • Risks include thrombotic complications, especially in patients with chronic liver disease 1, 3

Rituximab

• May be considered for patients at risk of bleeding who have failed one line of therapy such as corticosteroids, IVIg, or splenectomy 2
• Response rate: 31-79% in children; similar rates in adults 2

Other Second-Line Options

• Azathioprine: 1-2 mg/kg (max 150 mg/day)

  • Response rate: Up to two-thirds of patients
  • Slow response (3-6 months) 2

• Cyclosporin A: 5 mg/kg/day for 6 days then 2.5-3 mg/kg/day

  • Response rate: 50-80%
  • Response time: 3-4 weeks 2

• Cyclophosphamide: 1-2 mg/kg orally daily or IV (0.3-1 g/m² for 1-3 doses every 2-4 weeks)

  • Response rate: 24-85%
  • Response time: 1-16 weeks 2

• Danazol: 200 mg 2-4 times daily

  • Response rate: Up to 67%
  • Response time: 3-6 months 2

• Dapsone: 75-100 mg

  • Response rate: Up to 50%
  • Response time: 3 weeks 2

• Mycophenolate mofetil: 1000 mg twice daily

  • Response rate: Up to 75%
  • Response time: 4-6 weeks 2

Special Populations

Pregnant Patients

• Recommended treatments: Corticosteroids or IVIg 2
• Mode of delivery should be based on obstetric indications, not platelet count 2

Secondary ITP

• HCV-associated ITP: Consider antiviral therapy first; if ITP treatment required, use IVIg initially 2
• HIV-associated ITP: Consider antiviral therapy first; if ITP treatment required, use corticosteroids, IVIg, or anti-D 2
• H. pylori-associated ITP: Eradication therapy if H. pylori infection confirmed 2

Treatment Algorithm

1. Initial Assessment:

   • Treat if platelet count <30 × 10⁹/L or if bleeding symptoms present 1
   • Screen for secondary causes (HCV, HIV, H. pylori) 1

2. First-line Treatment:

   • Start with prednisone 1-2 mg/kg/day or dexamethasone 40 mg/day for 4 days
   • For rapid response: Add IVIg 1 g/kg or anti-D (if Rh+ and non-splenectomized)
   • Taper corticosteroids within 4 weeks

3. If No Response or Relapse After First-line:

   • Consider splenectomy (traditional second-line therapy)
   • Alternative: Thrombopoietin receptor agonists or rituximab if patient refuses splenectomy or has contraindications

4. If No Response to Second-line:

   • Try alternative second-line agents not previously used
   • Consider combination therapies

Monitoring and Goals

• Monitor platelet count weekly during dose adjustments, monthly after stable dose
• Goal: Increase platelet count to safe levels (>30-50 × 10⁹/L) to prevent bleeding 1
• Treatment should focus on preventing bleeding, not normalizing platelet counts 1

Common Pitfalls and Caveats

• Avoid prolonged steroid use due to significant adverse effects
• Overtreatment should be avoided - focus on bleeding prevention, not platelet count normalization
• Diagnostic errors can occur - ensure proper testing for secondary causes before treatment
• Romiplostim carries risks of thrombotic complications, especially in patients with chronic liver disease or those who develop very high platelet counts 1, 3
• Splenectomy, while effective, carries lifelong risk of serious infections and should be carefully considered 4