Prevention of dextran-induced anaphylactic reactions by hapten inhibition. III. A Scandinavian multicenter study on the effects of 20 ml dextran 1, 15%, administered before dextran 70 or dextran 40.

In an open, prospective multi-center study prevention of dextran-induced anaphylactic reactions (DIAR) was attempted by intravenous injection of 20 ml dextran 1, 15%, Mw 1000 dalton, (Promiten), two minutes before start of infusion of dextran 70 (Macrodex) or dextran 40 (Rheomacrodex). Of 34955 patients investigated, only one developed a severe DIAR of grade III (0.003%). The incidence of severe DIAR after preinjection of 20 ml dextran 1 is significantly lower than that after injection of 10 ml dextran 1 (p = 0.01), and is also markedly lower than that of a large Swedish historical control material (0.037-0.050%). The incidence of mild DIAR is not affected by dextran 1. Adverse reactions to dextran 1 of a generally mild and short-lasting nature were observed in 20 patients. It is recommended that patients who are going to receive dextran 70 or 40 are given a prophylactic i.v. injection of 20 ml dextran 1 before the first unit of clinical dextran to minimize the risk of severe DIAR.