Prevention of dextran-induced anaphylactic reactions by hapten inhibition. I. A Scandinavian multicenter study on the effects of 10 ml dextran 1, 15% administered before dextran 70 or dextran 40.

In an open prospective study the prevention of dextran-induced anaphylactic reactions (DIAR) by hapten inhibition was investigated in 29 252 patients. Forty-nine hospitals in Sweden, Norway and Finland participated in the study which was running for two years. Ten ml of dextran 1, 15%, (Promiten, Pharmacia AB, Uppsala, Sweden) with a weight average molecular weight of 1 000 dalton was injected intravenously two minutes before infusion of dextran 70 (Macrodex) or dextran 40 (Rheomacrodex). DIAR were graded according to severity from I to V. Six grade III and one grade IV reactions occurred, representing an incidence of severe DIAR of 0.024%. Compared to a large historical control material, preinjection of 10 ml of dextran 1 exerts a partially protective effect, but no statistical proof can be given. Consequently trials have been started with a 20 ml dose of dextran 1. Adverse reactions to the preinjection of 10 ml of dextran 1 were observed in 0.072%. These reactions were of a mild and shortlasting nature and considered to be of minor clinical importance.