Assessment of drug interactions with warfarin in patients diagnosed with Primary Antiphospholipid Syndrome

• Grant number: 21/14607-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2022
• End date: October 31, 2022
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Fernanda Loureiro de Andrade Orsi
• Grantee: Raquel Manta Dias de Carvalho
• Host Institution: Faculdade de Ciências Médicas (FCM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 16/14172-6 - Investigation of the pathophysiological aspects and novel therapeutic approaches for thromboembolic disorders, AP.TEM

Abstract

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by persistent production of antiphospholipid autoantibodies (aPL), which are anticardiolipin (aCL), anti-²2glycoprotein-1 (a²2GP1) or lupus anticoagulant (LA), responsible for generating a prothrombotic state through the activation of endothelial cells, monocytes, and platelets. This pro-thrombotic state brings vascular and obstetrical complications, such as arterial and venous thrombosis and recurrent abortions. The diagnosis is made through tests for aPLs and the treatment of thrombotic events is anticoagulant therapy with vitamin K antagonists (AVK) for an indeterminate time. The main AVK used is warfarin, provided to patients via SUS. The therapeutic effect of warfarin has inter and intrapersonal variation and therefore INR levels must be controlled (International Normalized Ratio), for a therapeutic range between 2 and 3. However, maintaining this therapeutic range is difficult, mainly by drug interaction. Thus, this cohort study aims to identify drug interactions in patients with primary APS and thrombosis undergoing treatment at the Blood Center of the State University of Campinas (UNICAMP) and to assess the impact of these interactions in controlling the therapeutic range of warfarin. THE estimation of the therapeutic effectiveness of warfarin will be performed by determining the TTR (Time in Therapeutic Range) based on the INR values measured in the past 6 months, and the risk of bleeding will be measured by the HAS-bled instrument. (AU)