The effect of prednisone on platelet function tests.

Ivy bleeding time, capillary fragility, threshold ADP concentration for secondary platelet aggregation and platelet adhesiveness were found to be unchanged by 2 d and 6 weeks of treatment with prednisone in 22 consecutive patients with collagen or haematological diseases. Initial high platelet counts were unchanged after 2 d of treatment, but after 6 weeks of treatment the increase was significant. It is concluded that in patients of this category a 6-week treatment with commonly used doses of prednisone does not significantly affect platelet function.