Effect of low-dose heparin on the platelet count

Thrombocytopenia has been associated with the use of intravenous heparin, but the effect of low-dose, subcutaneously administered heparin on the platelet count is not known. We monitored the platelet counts in 50 patients admitted to a coronary care unit and given low doses of heparin for at least three days. No patient had thrombocytopenia during an observation period of 15 days. We conclude that routine measurement of the platelet count is unnecessary when low-dose heparin is used in this patient population.