Intravenous immune globulin: dosage and administration.

Intravenous immune globulin (IV-IgG) is approved for use in substitution therapy of immunodeficiency syndromes and treatment of idiopathic thrombocytopenic purpura (ITP). The initial dose for substitution therapy is 0.2 g/kg body weight repeated monthly. If necessary, the dose may be increased to 0.3 g/kg and the frequency to every 2-3 weeks. The approved dosage for ITP is 0.4 g/kg daily for 2 to 5 consecutive days. Repeat doses of 0.4 g/kg have been used as maintenance therapy. The initial infusions of IgG to immunodeficient patients who have not been treated during the previous 8 weeks or never treated at all should proceed with caution. These patients are at risk of potentially serious complement-mediated adverse reactions. Adverse reactions due to IgG administration are less frequent and less severe for patients with ITP. Currently available preparations are contraindicated in patients with a selective IgA deficiency and detectable IgA antibodies.