Not all intravenous immunoglobulin preparations are equally well tolerated.

Intravenous immunoglobulin (IVIG) is used for many indications beyond the original substitution in primary antibody deficiency. Whereas many reports mention adverse reactions, no comparative data exist concerning the incidence of side-effects among the different brands of IVIG. We describe here our experience with the use of different IVIG formulations and their tolerability in a select cohort of 40 patients. The IVIG dose ranged from 0.4 to 3 g/kg/day and was given for 1-2742 days. Fourteen patients (35%) experienced mild to severe adverse reactions during or within 48 h of administration of standard IVIG preparation, which did not recur after switching to an alternative preparation. Adverse reactions included headache, fever, chills, nausea, emesis, hypotension and muscle cramps. One patient experienced a severe adverse reaction; he had a 3-day headache following IVIG infusion. Among the 16 patients who received alternative preparation initially, none experienced adverse reactions. In conclusion, this study shows that IVIG preparations are not all equally well tolerated in patients. The data suggest that, perhaps to a comparable extent to the preparation itself, the infusion rate has a major effect. If a reduction in the infusion rate does not minimize side-effects, one should consider switching the IVIG formulation.