Edith A Nutescu1. 1. College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA. enutescu@uic.edu
Abstract
PURPOSE: To describe the mechanisms of action, pharmacokinetics, and rate of bleeding complications from warfarin and target-specific oral anticoagulants; methods for assessing the risk for thromboembolism and bleeding in patients receiving oral anticoagulants or temporarily interrupting such therapy to undergo elective invasive procedures or surgery; therapeutic strategies for balancing these risks; and coagulation assays used to monitor oral anticoagulation therapy. SUMMARY: The target-specific oral anticoagulants have a more specific mechanism of action and shorter elimination half-lives than warfarin, but the half-lives of these target-specific agents may be prolonged in patients with renal impairment or elderly patients, resulting in the potential for drug accumulation and bleeding complications. The rate of bleeding complications in the community setting may be higher than in the clinical trial setting. In patients receiving oral anticoagulants or temporarily interrupting oral anticoagulant therapy to undergo elective invasive procedures or surgery, the risks for thromboembolism and bleeding should be assessed by using validated risk scoring systems and patient stratification schemes. The time during which an oral anticoagulant should be withheld before an invasive procedure or surgery and the time until resumption of therapy after the procedure depend on the drug, risk of thrombosis, type of procedure (i.e., risk for bleeding), and patient-specific variables, especially renal function for the target-specific agents. New coagulation assays are in development for use in monitoring oral anticoagulant therapy. CONCLUSION: An individualized approach is needed to balance the risks for thromboembolism and bleeding in patients receiving oral anticoagulants.
PURPOSE: To describe the mechanisms of action, pharmacokinetics, and rate of bleeding complications from warfarin and target-specific oral anticoagulants; methods for assessing the risk for thromboembolism and bleeding in patients receiving oral anticoagulants or temporarily interrupting such therapy to undergo elective invasive procedures or surgery; therapeutic strategies for balancing these risks; and coagulation assays used to monitor oral anticoagulation therapy. SUMMARY: The target-specific oral anticoagulants have a more specific mechanism of action and shorter elimination half-lives than warfarin, but the half-lives of these target-specific agents may be prolonged in patients with renal impairment or elderly patients, resulting in the potential for drug accumulation and bleeding complications. The rate of bleeding complications in the community setting may be higher than in the clinical trial setting. In patients receiving oral anticoagulants or temporarily interrupting oral anticoagulant therapy to undergo elective invasive procedures or surgery, the risks for thromboembolism and bleeding should be assessed by using validated risk scoring systems and patient stratification schemes. The time during which an oral anticoagulant should be withheld before an invasive procedure or surgery and the time until resumption of therapy after the procedure depend on the drug, risk of thrombosis, type of procedure (i.e., risk for bleeding), and patient-specific variables, especially renal function for the target-specific agents. New coagulation assays are in development for use in monitoring oral anticoagulant therapy. CONCLUSION: An individualized approach is needed to balance the risks for thromboembolism and bleeding in patients receiving oral anticoagulants.