Background and importance Intravenous immunoglobulin (IVIG) therapy is relatively expensive and requires careful use. IVIG dosing is based on actual body weight (ABW) but it is mainly distributed in the extracellular and intravascular space and minimally in body fat. This would allow adjusting the dose by ideal body weight (IBW) or adjusted body weight (AdjBW), reducing the dose per patient.

Aim and objectives The objective of this study was to describe the efficiency of precision dosing (PD) compared with ABW dosing in the initial dose of IVIG in patients with haematological malignancies.

Material and methods This was a retrospective descriptive study from May 2008 to September 2019. Patients with haematological malignancies who had received at least one dose of IVIG were included. Exclusion criteria were: <18 years of age and absence of anthropometric and/or clinical data. PD was defined as the use of IBW (Devine formula in men and Robinson formula in women) for dose calculation except: (1) ABW <IBW, dosing with ABW, (2) body mass index (BMI) ≥30 kg/m² or ABW ≥20% IBW, dosing based on AdjBW (AdjBW=IBW+0.5×(ABW−IBW)). Variables from the electronic medical record and records of the hospital pharmacy service were sex, age, ABW, haematological pathology and initial dose of IVIG. Efficiency was determined by the difference (in grams) between the initial mean dose (DMI) per ABW versus PD and the percentage cost difference.

Results Of 88 initial patients who met the inclusion criteria, 39 were excluded. The remaining 49 patients, 22 men and 27 women, had a mean age of 60±18 years, mean ABW of 74±17 kg and mean BMI of 28±5 kg/m². The results are summarised in table 1.

Conclusion and relevance In our population, the use of PD lowered consumption (in grams) compared with AWB. This dosing strategy can be an efficient and easy measure to implement for routine IVIG prescriptions.

References and/or acknowledgements No conflict of interest.