Treatment of an acute flush reaction caused by subcutaneous r‐hirudin with pegylated hirudin

Abstract
We report a patient who was treated with recombinant (r)‐hirudin for heparin‐induced thrombocytopenia and developed a flush reaction twice upon re‐exposure to 25 mg of subcutaneous r‐hirudin. Antihirudin IgG antibodies developed. 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 influenced by the patient's IgG antihirudin antibody. PEG‐hirudin may be used in patients with intolerance to r‐hirudin because of a dissociation of the allergenic and immunogenic properties of the pegylated drug.