A Case of Liver Failure Due to Dabigatran Treated with Venovenous Hemodiafiltration and Idarucizumab

Liver injury from direct oral anticoagulants

BACKGROUND

Drug-induced liver injury (DILI) can be caused by any prescribed drug and is a significant reason for the withdrawal of newly launched drugs. Direct-acting oral anticoagulants (DOACs) are non-vitamin K-based antagonists recently introduced and increasingly used for various clinical conditions. A meta-analysis of 29 randomised controlled trials and 152116 patients reported no increased risk of DILI with DOACs. However, it is challenging to predict the risk factors for DILI in individual patients with exclusion of patients with pre-existing liver disease from these studies.

AIM

To determine the risk factors and outcomes of patients who developed DILI secondary to DOACs by systematic review and meta-summary of recent case reports and series.

METHODS

A systematic search was conducted on multiple databases including PubMed, Science Direct, Reference Citation Analysis, and Google Scholar. The search terms included “Acute Liver Failure” OR “Acute-On-Chronic Liver Failure” OR “Acute Chemical and Drug Induced Liver Injury” OR “Chronic Chemical and Drug Induced Liver Injury” AND “Factor Xa Inhibitors” OR “Dabigatran” OR “Rivaroxaban” OR “apixaban” OR “betrixaban” OR “edoxaban” OR “Otamixaban”. The results were filtered for literature published in English and on adult patients. Only case reports and case studies reporting cases of DILI secondary to DOACs were included. Data on demographics, comorbidities, medication history, laboratory investigations, imaging, histology, management, and outcomes were extracted.

RESULTS

A total of 15 studies (13 case reports and 2 case series) were included in the analysis, comprising 27 patients who developed DILI secondary to DOACs. Rivaroxaban was the most commonly implicated DOAC (n = 20, 74.1%). The mean time to onset of DILI was 40.6 d. The most common symptoms were jaundice (n = 15, 55.6%), malaise (n = 9, 33.3%), and vomiting (n = 9, 33.3%). Laboratory investigations showed elevated liver enzymes and bilirubin levels. Imaging studies and liver biopsies revealed features of acute hepatitis and cholestatic injury. Most patients had a favourable outcome, and only 1 patient (3.7%) died due to liver failure.

CONCLUSION

DOACs are increasingly used for various clinical conditions, and DILI secondary to DOACs is a rare but potentially serious complication. Prompt identification and cessation of the offending drug are crucial for the management of DILI. Most patients with DILI secondary to DOACs have a favourable outcome, but a small proportion may progress to liver failure and death. Further research, including post-marketing population-based studies, is needed to better understand the incidence and risk factors for DILI secondary to DOACs.

Rivaroxaban Reduces the Dabigatran Dose Required for Anticoagulation During Simulated Cardiopulmonary Bypass

BACKGROUND

Heparin is the standard anticoagulant for cardiopulmonary bypass (CPB); however, there are problems with its use that make the development of suitable alternatives desirable. Currently, no ideal alternative exists. We have previously reported that the direct thrombin inhibitor dabigatran can prevent coagulation in simulated CPB at high concentrations. These high concentrations may cause difficulties in achieving the reversal of dabigatran with idarucizumab, given the markedly different pharmacokinetics of the 2 drugs. Herein, we test the hypothesis that the addition of the anti-Xa drug rivaroxaban would provide suitable anticoagulation at a lower concentration of dabigatran given likely synergy between the 2 classes of drugs. The primary goal of the study was to investigate whether the addition of rivaroxaban reduces the concentration of dabigatran necessary to allow 2 hours of simulated CPB.

METHODS

The study was performed in sequential steps. Blood collected from consenting healthy donors was used throughout. First, we added graded concentrations of dabigatran and rivaroxaban alone and in combination and assessed inhibition of anticoagulation using thromboelastometry. Using results from this step, combinations of dabigatran and rivaroxaban were tested in both Chandler loop and simulated CPB circuits. Dabigatran and rivaroxaban were added before recalcification, and the circuits were run for 120 minutes. In both models of CPB, 120 minutes of circulation without visible thrombus was considered successful. In the Chandler loop system, idarucizumab was added to reverse anticoagulant effects. In the CPB circuits, the arterial line filters were examined using scanning electron microscope (SEM) to qualitatively assess for fibrin deposition.

RESULTS

In vitro analysis of blood samples treated with dabigatran and rivaroxaban showed that dabigatran and rivaroxaban individually prolonged clotting time (CT) in a dose-dependent manner. However, when combined, the drugs behaved synergistically. In the Chandler loop system, dabigatran 2400 and 4800 ng/mL plus rivaroxaban (150 ng/mL) effectively prevented clot formation and reduced the dynamics of clot propagation for 120 minutes. Idarucizumab (250-1000 µg/mL) effectively reversed anticoagulation. In the CPB circuits, dabigatran (2500 ng/mL) and rivaroxaban (200 ng/mL) were successful in allowing 120 minutes of simulated CPB and prevented fibrin deposition. Biomarkers of coagulation activation did not increase during simulated CPB. Heparin controls performed similarly to dabigatran and rivaroxaban.

CONCLUSIONS

The dual administration of oral anticoagulant drugs (dabigatran and Rivaroxaban) with different pharmacologic mechanisms of action produced synergistic inhibition of coagulation in vitro and successfully prevented clotting during simulated CPB.