Antiplatelet effects of antidepressant treatment: A randomized comparison between escitalopram and nortriptyline

IntroductionDepressive disorders have been identified as independent risk factors for coronary heart disease. The present study (i) compared platelet function of depressed patients with that of healthy controls, (ii) analysed possible aggregability changes during 3 months of treatment with antidepressants, and (iii) sought to assess different effects of escitalopram and nortriptyline on platelet aggregation.MethodsBlood samples of 91 major depressed patients and 91 healthy controls were analysed with whole blood aggregometry in a case-control setting. Depressed patients were randomized to two groups treated either with escitalopram (n = 47) or nortriptyline (n = 44). Platelet aggregation was studied on days 0, 1, 3, 7, 14, 21, 84 of continuing medication and was determined in response to adenosine diphosphate (ADP) and collagen.ResultsPlatelet aggregation induced by ADP was increased among depressive patients compared with that of healthy controls (26%, p = 0.006). With antidepressant treatment, changes in platelet aggregation remained comparable in both groups at early time points (d1 to 21). In contrast, at day 84, patients with antidepressive response revealed significant differences in both medication groups: Patients receiving escitalopram showed a 23% decrease of ADP induced aggregation (p = 0.03) and a 15% decrease of collagen induced aggregation (p = 0.03). With nortriptyline the increase in impedance was reduced by 29% after ADP induction (p = 0.046).ConclusionDepressed patients have higher ex vivo platelet aggregation that may contribute to increased cardiovascular morbidity. After three months of antidepressant treatment with either escitalopram or nortriptyline, platelet aggregation was significantly reduced in antidepressant responders, irrespective of the antidepressant medication type.