The Effect of Sulfinpyrazone and Aspirin on the IVY Template Bleeding Time

The Canadian Stroke Study has afforded us an opportunity to study the effect of sulfinpyrazone 800 mg daily, aspirin 1200 mg daily, both drugs together, and a placebo on the Ivy template bleeding time. Patients with transient cerebral ischemic attacks were randomized to one of the treatment groups and studied before and during treatment.In 352 patients studied pre-drug, the mean bleeding time was 5.02 ± 2.38 (± 1 SD) minutes. Aspirin significantly prolonged the bleeding time (p=.001). Sulfinpyrazone alone had no effect on the bleeding time. In patients receiving both drugs, the effect was no greater than that of aspirin alone. 51Cr platelet survival studies have been completed in 47 patients during treatment. The mean of 8.4 days was similar to the mean in 17 normal controls(8.3 days). However, analysis by treatment groups remains to be done.