Comparison of low-dose subcutaneous heparin calcium and heparin sodium on ecchymosis formation

Ecchymosis formation in patients receiving identical concentrations of heparin calcium or heparin sodium was compared in a double-blind study. Sixty-three patients admitted to a coronary-care unit with orders to receive heparin 5000 units subcutaneously every 12 hours were randomly assigned to receive either heparin calcium or heparin sodium. The drugs were administered identically. The presence and size of any ecchymosis were recorded by a single observer. The 44 patients on whom data were collected received 86 heparin sodium and 102 heparin calcium injections. While there were no difference between salts in the percentage of patients with documented ecchymosis , significantly more injection sites with ecchymosis were reported for the calcium salt. No significant difference was found in bruise size between the calcium and sodium salts of heparin. In a subgroup of patients who were not receiving other drugs known to prolong bleeding, there was no significant difference between the salts in the percentage of patients and injection sites with ecchymosis . The subcutaneous administration of heparin calcium resulted in significantly more injection sites with ecchymosis than did heparin sodium, but the size of the reported ecchymosis was not different between the two groups.