Treatment of an acute flush reaction caused by subcutaneous r-hirudin withpegylated hirudin

We report a patient who was treated with recombinant (r)-hirudin for hepari n-induced thrombocytopenia and developed a flush reaction twice upon re-exp osure to 25 mg of subcutaneous r-hirudin. Antihirudin IgG antibodies develo ped. The patient received 50 mg of PEG-hirudin subcutaneously over 2 days. No side-effects occurred. The level of IgG antihirudin antibodies increased . Ecarin clotting time and thrombin inhibition S2238 assay were not influen ced by the patient's IgG antihirudin antibody. PEG-hirudin may be used in p atients with intolerance to r-hirudin because of a dissociation of the alle rgenic and immunogenic properties of the pegylated drug.