Antigenicity of dextrans is directly related to their degree of branching. Since LMD (dextran 40) has a low degree of branching, it is relatively free of antigenic effect. However, a few individuals have experienced mild urticarial reactions. More severe reactions, consisting of severe anaphylactoid reaction, generalized urticaria, tightness of the chest, wheezing, hypotension, nausea and vomiting may occur in rare instances. Symptoms and signs of adverse systemic reaction may be relieved by parenteral administration of antihistamines, ephedrine or epinephrine, while other means of shock therapy are instituted. The route of administration and dosages of the therapeutic agent selected will depend upon the severity and rapidity of progression of the reaction.
Reactions which may occur because of the solution or the technique of administration include febrile response, infection at the site of injection, venous thrombosis or phlebitis extending from the site of injection, extravasation and hypervolemia.
If an adverse reaction does occur, discontinue the infusion, evaluate the patient, institute appropriate therapeutic countermeasures, and save the remainder of the fluid for examination if deemed necessary (see WARNINGS for treatment of anaphylactic shock).
Severe reactions have been observed with Dextran 40 and Dextran 70. Reported reactions include: generalized urticaria, nausea and vomiting, wheezing, hypotension, shock and cardiac arrest (dextran-induced anaphylactoid reactions, DIAR). FDA has received 94 reports of severe DIAR since 1964. Because these reactions are reported voluntarily and the treated population is of indeterminate size, the frequency of reactions cannot be estimated reliably.