CP-107 Drug utilisation study of human normal immunoglobulin in immunodeficient patients in a tertiary paediatric hospital

Background Human normal immunoglobulin (HNIg) indications are replacement therapy for primary or secondary immune deficiencies (ID) and as immunomodulatory therapy for several autoimmune disorders. Since the only way to obtain HNIg is from plasma donors, it represents a valuable, limited and expensive resource. As a consequence, it is necessary for pharmacists to evaluate their use based on scientific indications. Purpose To describe the use of HNIg as replacement therapy in chronic patients with ID in a tertiary referral paediatric hospital. Material and methods Based on medical history records, we collected and analysed cross sectional data from immunodeficient patients in our immunology department receiving replacement therapy with either subcutaneous or intravenous HNIg. We established a normal dosage range for subcutaneous replacement therapy of 100–200 mg/kg, self-administered on a weekly basis. For the intravenous infusion, the normal dosage range was defined as 200–800 mg/kg every 3–4 weeks, although our centre’s standard initial dose was 400–500 mg/kg every 4 weeks. In both cases, the initial dose was later titrated based on plasma immune globulin levels and number of infectious episodes. Results After analysing data obtained from 34 patients, we found that the majority of immunodeficiences treated were primary ID (29/34), mainly common variable immune deficiency disease (CVID, 12/34) the primary indication, followed by Bruton syndrome (5/34) and ataxia telangiectasia (4/34). Most of the patients were treated by intravenous infusion (28/34) with a median monthly dose of 441 mg/kg (355–739). Regarding patients treated by subcutaneous injection (6/34), the median monthly dose was 459 mg/kg (416–541). One patient needed a shortened interval to every 3 weeks to control recurrent infections episodes. Conclusion Primary ID is the major diagnostic immunodeficiency treated by our immunology department, which might be due to the complexity of patients treated by this unit. No patients exceeded the normal dosage range reported in the literature; most patients were treated with a monthly periodicity showing a favourable clinical evolution, although the shortened interval treatment allowed a clinical response to be achieved without increasing the monthly total HNIg dose. References and/or acknowledgements Special acknowledgements to all pharmacy staff. No conflict of interest