Antidepressant Treatment and Global Tests of Coagulation and Fibrinolysis

Letter to the Editor

Sir: Although rare, an increased tendency for bleeding has been associated with various antidepressants, causing justifiable concern. Knowledge about the mechanisms underlying this phenomenon is scarce. The phenomenon is believed to represent interactions of drugs with other drugs or with the serotonergic system of platelets. Furthermore, there is some evidence that depressive disorders by themselves may affect hemostatic function. To further our understanding of the clotting cascade during antidepressant treatment, we analyzed global tests of coagulation and fibrinolysis before and after treatment with either amitriptyline, a tricyclic compound, or paroxetine, which is characterized predominantly by its mode of action, namely selective serotonin reuptake inhibition.