The effect of long‐term colchicine therapy in patients with recurrent polyserositis on the capacity of blood platelets to synthesize thromboxane A2.

Thromboxane B2 (TXB) production during platelet activation was measured in 13 patients with recurrent polyserositis on long-term colchicine therapy and 10 healthy controls. Plasma colchicine concentration in patients ranged between 0.8-7.8 ng/ml (2.0-19.5 X 10(-9) M). Thromboxane production induced during aggregation by arachidonic acid or collagen and serum TXB2 levels (clotted blood, 37 degrees C, 1 h) did not differ among patients and controls. Previous studies reporting platelet function defects including anomalous TXB2 production, were performed in vitro using colchicine concentrations markedly exceeding the therapeutic range.