Acquired Resistance to Prolonged Treatment with Intravenous “Arvin” (Ancrod)

Abstract

The duration of therapy with the anticoagulant "Arvin" may be limited by acquired resistance, the patient developing specific anti-bodies when the drug is given intramuscularly. subcutaneously or intravenously (Pitney et al.. 1969). We report the case of a patient with recurrent thrombo-embolic disease who was given intravenous Arvin for a total of 45 days before developing resistance. There were no signs of an allergic reaction associated with this resistance.