Overview of routes of IgG administration.

The use of exogenous serum to provide protection against infections began more than a century ago. Over time, this concept matured and led to the preparation of concentrated immunoglobulin (IgG) products that were safe and effective when delivered subcutaneously (SC) or intramuscularly (IM) but were not ideal for intravenous (IV) use. Continued improvements led to the development of IgG preparations that are safe for either subcutaneous IgG (SCIG) or intravenous IgG (IVIG) delivery and allow providers and patients significant flexibility to develop an effective but manageable treatment plan. Factors that influence the choice of IgG product and delivery method can maximize the therapeutic benefit and provide the best possible quality of life for patients.