STUDY OF HEMOSTASIS IN DEPRESSIVE PATIENTS TREATED WITH FLUOXETINE

The object of this study was to investigate a possible pharmacological effect of fluoxetine on haemostatic function, with special attention on primary haemostasis, in order to explain haemorrhagic complications reported in some treated, depressed patients. The haemostatic functio n of depressive patients, who required fluoxetine therapy, was studied before and after 1 month of treatment with fluoxetine 20 or 40 mg dai ly. Exclusion criteria were: pregnancy, initial abnormal haemostatic f unction, history of coagulation abnormalities, treatment with drugs th at interfere with haemostasis, and recent fluoxetine therapy. The foll owing tests were performed: prothrombin time, partial thromboplastin t ime, thrombin time, plasma fibrinogen, platelet counts, bleeding time, platelet aggregation induced by ADP, epinephrine, ristocetin, collage n, arachidonic acid, and plasma determination of fluoxetine and norflu oxetine levels. Statistical analysis was performed by Wilcoxon paired sample, one-tailed test (alpha=0.05). Among 18 patients included, only eight completed the trial. The single statistically significant diffe rence was a decreased velocity in platelet aggregation induced by epin ephrine without increased bleeding time. The results failed to demonst rate any compromised haemostatic function after 20 mg daily fluoxetine therapy in patients with initial haemostatic function. However, the r esults suggest possible effects of fluoxetine on platelet adrenorecept ors. (C) 1998 John Wiley & Sons, Ltd.