Enoxaparin reduces cerebral edema after photothrombotic injury in the rat

This study investigates the effect of enoxaparin (Lovenox, Klexane), a low- molecular-weight heparin, on edema following a photothrombotic lesion using rose bengal dye in the rat. An area of cerebral ischemia was provoked in t he right hemisphere of rats. Edema developed over 24 h after the lesion, as seen comparing water content of a core sample from the right hemisphere to that of a similar sample from the left hemisphere of each rat. Enoxaparin at 0.5 mg/kg i.v. plus 2 mg/kg s.c. reduced edema 24 h after lesion inducti on by 32% (p < 0.01) when the treatment was started 2 h after photothrombot ic insult, with maintenance doses of 2 mg/kg s.c. enoxaparin at 6 and 18 h. When the same initial treatment with enoxaparin was started 18 h after ins ult, there was still a significant reduction of 20% (p < 0.01) in cerebral edema. Administration of enoxaparin 18 h after insult reduced cerebral edem a in a dose-dependent manner. There was no evidence of intracranial hemorrh ages in any of the animal groups and when the hemoglobin content of the bra in samples was assayed by the method of Drabkin, no increase in hemoglobin content was seen compared to sham-operated animals.