The risk of thrombosis in patients with chronic liver disease is increasingly recognized. As patients with cirrhosis develop indications for anticoagulation therapy (e.g., venous thromboembolism, portal vein thrombosis, or atrial fibrillation), providers are left to make difficult decisions when selecting therapeutics with little evidence to rely on. Current practice supports the use of low molecular weight heparin or vitamin K antagonists in select patients with cirrhosis requiring anticoagulation. While traditional anticoagulants may be safe and effective in select patients with compensated cirrhosis, the use of direct oral anticoagulants (DOAC) is more controversial. DOAC are desirable as they do not require routine monitoring and can be taken orally. Unfortunately, patients with chronic liver disease were excluded from clinical trials that demonstrated efficacy and safety when compared to traditional anticoagulation. Data are now emerging that support the use of DOAC in well-compensated cirrhosis patients. However, further study is needed with all (traditional and DOAC) anticoagulation medications in patients with cirrhosis to better ensure safety and further understand pharmacologic properties in this challenging population.

We assessed the hepatic safety of novel oral anticoagulants (NOACs) analyzing the publicly available US-FDA adverse event reporting system (FAERS).

We extracted reports of drug-induced liver injury (DILI) associated with NOACs, including acute liver failure (ALF) events. Based on US marketing authorizations, we performed disproportionality analyses, calculating reporting odds ratios (RORs) with 95% confidence interval (CI), also to test for event- and drug-related competition bias, and case-by-case evaluation for concomitant medications.

DILI reports represented 3.7% (n = 146) and 1.7% (n = 222) of all reports for rivaroxaban and dabigatran, respectively. No statistically significant association was found for dabigatran, in primary and secondary analyses. Disproportionality signals emerged for rivaroxaban in primary analysis (ALF: n = 25, ROR = 2.08, 95% CI 1.34, 3.08). In a large proportion of DILI reports concomitant hepatotoxic and/or interacting drugs were recorded: 42% and 37% (rivaroxaban and dabigatran, respectively), especially statins, paracetamol and amiodarone. Among ALF reports, fatal outcome occurred in 49% of cases (44% and 51%, rivaroxaban and dabigatran, respectively), whereas rapid onset of the event (<1 week) was detected in 46% of patients (47% and 44%, respectively).

The disproportionality signal for rivaroxaban calls for further comparative population-based studies to characterize and quantify the actual DILI risk of NOACs, taking into account drug- and patient-related risk factors. As DILI is unpredictable, our findings strengthen the role of (a) timely pharmacovigilance to detect post-marketing signals of DILI through FAERS and other data sources, (b) clinicians to assess early, on a case-by-case basis, the potential responsibility of NOACs when they diagnose a liver injury.

Drug-induced liver injury (DILI) and herb-induced liver injury is a hot topic for clinicians, academia, drug companies and regulators, as shown by the steadily increasing number of publications in the past 15 years. This review will first provide clues for clinicians to suspect idiosyncratic (unpredictable) DILI and succeed in diagnosis. Causality assessment remains challenging and requires careful medical history as well as awareness of multifaceted aspects, especially for herbs. Drug discontinuation and therapy reconciliation remain the mainstay in patent's management to minimize occurrence of acute liver failure. The second section will address novel agents associated with liver injury in 2014 (referred to as "signals"), especially in terms of clinical, research and drug development implications. Insights will be provided into recent trends by highlighting the contribution of different post-marketing data, especially registries and spontaneous reporting systems. This literature scrutiny suggests: (1) the importance of post-marketing databases as tools of clinical evidence to detect signals of DILI risk; and (2) the need for joining efforts in improving predictivity of pre-clinical assays, continuing post-marketing surveillance and design ad hoc post-authorization safety studies. In this context, ongoing European/United States research consortia and novel pharmaco-epidemiological tools (e.g., specialist prescription event monitoring) will support innovation in this field. Direct oral anticoagulants and herbal/dietary supplements appear as key research priorities.