Effect of an activated charcoal product (DOAC Stop™) intended for extracting DOACs on various other APTT-prolonging anticoagulants

Background: The aim of the study was to investigate the specificity of an activated charcoal-based product (DOAC StopTM) initially intended for the specific extraction of direct oral anticoagulants (DOACs) from test plasmas on a range of other anticoagulants. Methods: Test plasmas were prepared by adding various anticoagulants to pooled normal plasma at concentrations prolonging an activated partial thromboplastin time (APTT) test by a factor of 1.5-3. These plasmas were treated with DOAC Stop (TM) for 5 and 20 min. Then APTTs were repeated and residual anticoagulant concentrations estimated from dose-response curves. Results: The activated charcoal (AC)-based product was found to extract DOACs efficiently. It also bound the intravenous anticoagulants argatroban and lepirudin, but it had no effect on heparin, enoxaparin or danaparoid in plasma. Among other APTT-inhibiting agents that might be present in test plasmas from patients, it extracted protamine, aprotinin and polymyxin. It had no effect on annexin V, thrombomodulin, a typical lupus anticoagulant, a factor VIII antibody, activated protein C or its activator, but it did bind some cationic inhibitors of the APTT with molecular weight below approximately 30 kDa. Conclusions: The AC-based product extracted DOACs efficiently with no effect on heparin-type anticoagulants. It did bind argatroban and hirudin-type anticoagulants, which might occur in plasmas from some inpatients, and APTT results obtained after its use should be interpreted after due consideration of patient medications.