Medication Summary
Glucocorticoids and intravenous immunoglobulin (IVIG) are the mainstays of medical therapy for immune thrombocytopenia (ITP). Indications for use, dosage, and route of administration are based on the patient's clinical condition, the absolute platelet count, and the degree of symptoms. Consultation with a hematologist may be needed prior to starting therapy.
In children with ITP who have no bleeding or mild bleeding (eg, cutaneous manifestations such as bruising and petechiae), the American Society of Hematology (ASH) recommends management with observation alone, regardless of the platelet count. [16] A retrospective review by Schultz et al found that this approach did not lead to an increase in later treatment or an increase in delayed bleeding symptoms. [21]
Adults with platelet counts > 50,000/mm3 do not require treatment. Treatment is indicated for adults with counts < 50,000/mm3 with significant mucous membrane bleeding. Treatment also is indicated for those adults with risk factors for bleeding (eg, hypertension, peptic ulcer disease, vigorous lifestyle) and in patients with a platelet count < 20,000-30,000/mm3.
IV Rho immunoglobulin (RhIG) is generally less toxic than IV steroids but is more expensive and has been associated with acute intravascular hemolysis, with an estimated incidence of one in 1115 patients. The ASH advises against the use of IV RhIG in splenectomized children, in those with a hemoglobin concentration that is decreased because of bleeding, or in those with evidence of autoimmune hemolysis. However, the ASH suggests that a single dose of IV RhIG can be used as first-line treatment in Rh-positive, nonsplenectomized children who require treatment. [16]
Steroid use and immunosuppressives and splenectomy may be undesirable because of their associated complications. For long-term steroid use, those include osteoporosis, glaucoma, cataracts, loss of muscle mass, and an increased risk of infection. For immunosuppressive therapy and splenectomy, risks include worsening immunosuppression and infection or sepsis.
Second-line options for treatment of ITP include rituximab and thrombopoietin receptor agonists (TPO-RAs). Rituximab has been used on its own as well as in combination with corticosteroids and in triple therapy with cyclosporine and dexamethasone. [22, 23, 24, 25]
The TPO-RAs eltrombopag, romiplostim, and avatrombopag are approved for use in patients with chronic ITP who have shown insufficient response to corticosteroids, immunoglobulins, or splenectomy. [26, 27, 28] With both agents there are potential safety concerns such as thrombocytosis and rebound thrombocytopenia. It is unlikely that emergency physicians should be prescribing these agents without the recommendation of a hematologist.
Glucocorticoids
Prednisone (Deltasone, Orasone, Sterapred)
Useful in treating inflammatory and allergic reactions; may decrease inflammation by reversing increased capillary permeability and suppressing PMN activity. DOC for all adult patients with platelet counts < 50,000/mm3. Asymptomatic patients with platelet counts >20,000/mm3, or patients with counts 30,000-50,000/mm3 with only minor purpura, may not need therapy; withholding medical therapy may be appropriate for asymptomatic patients, regardless of count.
Methylprednisolone (Solu-Medrol, Depo-Medrol)
Decreases inflammation by suppressing migration of polymorphonuclear leukocytes and reversing increased permeability. Used as alternative glucocorticoid of choice for all patients with severe, life-threatening bleeding or children with platelet counts < 30,000/mm3. Careful observation without medical treatment may be appropriate in some asymptomatic children.
Blood products
Intravenous immune globulin (IVIg)
Drug of choice for patients with severe, life-threatening bleeding or for children with platelet counts < 20,000/mm3 with minor purpura; can be used alone or in addition to glucocorticoid therapy.
Thrombopoietic Agents
Avatrombopag (Doptelet)
Second-generation orally administered thrombopoietin receptor agonist (TPO-RA). Stimulates proliferation and differentiation of megakaryocytes from bone marrow progenitor cells, resulting in an increased production of platelets
Eltrombopag (Promacta)
Oral thrombopoietin (TPO) receptor agonist. Interacts with transmembrane domain of human TPO receptor and induces megakaryocyte proliferation and differentiation from bone marrow progenitor cells. Indicated for thrombocytopenia associated with chronic immune thrombocytopenia in patients experiencing inadequate response to corticosteroids, immunoglobulins, or splenectomy. Not for use to normalize platelet counts but used when clinical condition increases bleeding risk.
Romiplostim (Nplate)
An Fc-peptide fusion protein (peptibody) that increases platelet production through binding and activation of the thrombopoietin (TPO) receptor, a mechanism similar to endogenous TPO. Indicated for chronic immune thrombocytopenia in patients who have had an insufficient response to corticosteroids, immunoglobulins, or splenectomy.
