Although human immunoglobulin has been used to treat primary immunodeficiency disorders (PIDDS) for decades, advancements in the development and manufacturing procedures of immunoglobulin have greatly expanded product options.
 
Because currently available immunoglobulin G (IgG) products vary, specialty pharmacists must be knowledgeable about the differences between these treatments and how they might affect specific patients. A Pharmacy Times Continuing Education activity provided an overview on how to best select products for patients.  
 
Immunoglobulin Product Consideration

With many options to choose from, pharmacists must be able to balance considerations in the composition and characteristics of each product. Careful consideration of product characteristics typically leads to therapy that is well-tolerated with minimal adverse events (AEs).
 
Product characteristics vary in composition, concentration, volume and rate of administration, and frequency and route of administration. Patient factors, including desired IgG levels, site of care and administration, education and training of patient and family, support for the administration of therapy, and management of potential AEs must all be considered as well.
 
Most immunoglobulin products currently on the market are formulated as liquids of varying concentrations. Lyophilized products are reconstituted with water, saline, or dextrose. However, liquid products are often preferred because they do not require reconstitution and have lower risk of hyperosmolarity than lyophilized products.
 
The volume required to be infused is another important consideration in many patients, especially infants, elderly individuals, and those with comorbid conditions who may be affected. Providers should aim to administer low volumes of IgG to those at high risk for volume overload.
 
When it comes to matching products to patients, factors related to tolerability should be weighed against patient risk factors. For example, high-risk patients should be treated with intravenous immunoglobulin (IVIG) products with low sodium content and low osmolality, as well as nonsugar stabilizers. Providers should also monitor patients’ renal function and concomitant cardiac conditions.
 
Adverse Events
 
AEs are most commonly seen with the first infusion of IVIG, with a longer period of time between infusions, or with a change in product. Careful attention to the maximum recommended infusion rate, as well as patient-specific reactions that may require a decrease in infusion rate, can prevent treatment interruption.
 
Often, the most common AE is headache. For moderate or intolerable AEs, a reduction in the infusion rate should be considered. Persistent AEs may be treated with anti-inflammatories, antihistamines, or low-dose corticosteroids; however, severe AEs may require discontinuation of the infusion and a transition to subcutaneous immunoglobulin.
 
Role of the Specialty Pharmacist
 
Overall, specialty pharmacists are in an ideal position to evaluate patient and product characteristics to select optimal therapies, administration site, infusion rate, and dosing. Providing comprehensive medication education and a consistent point of contact can help improve medication adherence, acceptability, and resulting efficacy.