A CLINICAL STUDY OF PROLONGED ANTICOAGULANT EFFECT WITH REPOSITORY BUTACAINE HEPARIN

¹ Department of Pharmacology, School of Medicine, University of Washington, Seattle, Washington

Butacaine-heparin injected intramuscularly in humans in aqueous suspension results in slow liberation of heparin into the systemic circulation. The duration of action on the clotting mechanism of single doses of this preparation is from 24 to 36 hours depending on the dose. By the addition of free sodium heparin to an aqueous suspension of butacaine-heparin maximum effect on the clotting time is reached in 3 hours with a duration of action of at least 24 hours. Systemic toxicity in the doses used was absent. Local tenderness at the site of injection occurring on the day following the injection and lasting from two to four days occurred in one out of four subjects receiving the preparations.