First-line or upfront therapy for idiopathic thrombocytopenic purpura

Steroids:

• prednisone 0.5–2 mg/kg/d PO tapered ~4 wk, or dexamethasone 40 mg PO × 4 d

• ↓ Mϕ FcR & ↓ anti-plt Ab

• 70–90% have initial response

• ~20% sustained remission

IVIg (1 g/kg/d IV × 2–3 d)

• Consider if need rapid ↑ in plt in 24–48 hrs; lasts 2–6 wks

• Blocks Mϕ FcR, ↓ anti-plt Ab

• Interferes w/ Mϕ uptake Ab-coated plts; 80% have initial response

Anti-Rh(D) Ig:

• alternative to IVIg if RBC Rh(D) ⊕; 50–75 mcg/kg/d

• Ab-coated RBCs overwhelm Mϕ FcR

• Avoid if h/o hemolysis; not often used