Effects of Rivaroxaban on Coagulation Assays in Patients with Small Pulmonary Embolism and Deep Vein Thrombosis in Relation to Body Mass Index

Introduction: Rivaroxaban is a new anticoagulant medication for pulmonary thromboembolism (PTE) and deep vein thrombosis (DVT). There are limited data on the effect of body mass index (BMI) on the pharmacokinetics of rivaroxaban. This study aimed to assess the effect of rivaroxaban on coagulation assays in relation to BMI in PTE and DVT patients. Materials and Methods: the present cohort studywas conducted on patients with DVT and PTE who were planned to receive rivaroxaban (15 mg bid). Demographic characteristics, as well as anthropometric measurements, were recorded before the rivaroxaban administration. Prothrombin time (PT), partial thromboplastin time (PTT), and international normalized ratio (INR) were measured before and after 4-6 days of treatment with rivaroxaban. The data were analyzed using paired t-test and analysis of covariance in SPSS software, version 20 (IBM Inc., Chicago, Il, USA). Results: This study was carried out on 100 subjects (i.e., 45 males and 55 females) with the mean age of 38.8±1.7 years. The majority of the subjects (68%) had normal creatinine clearance. The results of the research revealed a significant increase in PT, PT, and INR after the administration of rivaroxaban in both normal-weight and obese subjects (P 0.001 each). Additionally, it was found that the coagulation assays were increased significantly in all age (i.e., 40 and 40 years), gender, and creatinine clearance (i.e., normal and abnormal) groups (P 0.001 each). Furthermore, the final PTT was found to be related to age (P=0.011), while final PT was associated with BMI (P=0.035) and baseline PT (P=0.030). Conclusion: The findings of this study indicated a significant increase in coagulation assays in both normal weight and obese subjects; however, the final PT increment was reduced by BMI.