Effect of levamisole on aggregation of platelets stimulated with compounds associated with the prostaglandin synthetic pathway.

Levamisole, L-2,3,5,6-tetrahydro-6-phenylimidazo-(2,1-b)-thiazole-hydrocholoride at various concentrations (2.5 to 40 microgram) added to platelet rich plasma inhibited aggregation of platelets. The 50% inhibition concentrations (IC50) of levamisole in platelet aggregation induced by hydrogen peroixde (9.4 x 10(-1) mM), epinephrine (1.0 x 10(-1) micrometer), endoperoxide-analog (2.9 x 10(-1) micrometer) and arachidonic acid (3.3 micrometer) were 11.0, 8.0, 11.5 and 16.0 microgram/test, respectively. It is suggested that levamisole like imidazole inhibit platelet aggregation and this factor should be considered in the administration of levamisole, especially in cardiovascular diseases.