Lepirudin in the management of heparin-induced thrombocytopenia

Recombinant neorudin and its active metabolite hirudin: the fate in vivo of a novel anticoagulant drug

Thrombosis, a prevalent condition, can provoke severe health issues like acute coronary syndrome (ACS), deep vein thrombosis (DVT), and pulmonary embolism (PE). The rising incidence of these diseases annually significantly impacts patient wellbeing and poses a substantial burden on healthcare systems. Recombinant neorudin is a developing anticoagulant drug for thrombotic diseases whose phase I clinical trials has been completed. The distribution pattern of it and its active metabolite, hirudin, in thrombi, blood surrounding the thrombus and peripheral blood remains uncertain. This study explored their distribution using a rat arteriovenous bypass thrombosis model, revealing higher neorudin levels in blood surrounding the thrombus and elevated hirudin concentrations in thrombus. Recombinant neorudin significantly increased Thrombin Time (TT) in both plasma surrounding the thrombus and peripheral blood, and reduced the wet weight of the thrombus. The results above demonstrated the anticoagulant and antithrombotic efficacy of recombinant neorudin in vivo. Give the distribution pattern of neorudin and hirudin, we hypothesized that neorudin was cleaved at the site of thrombus formation to produce hirudin, leading to the rapid accumulation of hirudin within local thrombi and resulting in a higher concentration inside the thrombus. This insight was crucial for understanding the action mechanisms of anticoagulants in thrombosis management and provided a valuable guidance for therapeutic strategies in treating thrombotic diseases.

Acute Kidney Injury in Different Anticoagulation Strategies: A Large-Scale Pharmacoepidemiologic Study Using Real-World Data

PURPOSE

Acute kidney injury (AKI) following anticoagulant application has received growing attention as a significant emerging complication of anticoagulation. Nevertheless, there remains a lack of real-world studies to compare the incidence, clinical features, and prognosis of AKI across different anticoagulant regimens.

METHODS

Disproportionality analysis and Bayesian analysis were used to identify suspected AKI cases after different anticoagulant use within the Food and Drug Administration's Adverse Event Reporting System from January 2004 to March 2023. The time to onset, fatality, and hospitalization rates of anticoagulant-associated AKI were also investigated.

RESULTS

We identified 9313 anticoagulant-associated AKIs, which appeared to influence mostly patients over 65 years old (65.37%). Lepirudin displayed a stronger AKI association than others, based on the highest reporting odds ratio (ROR = 6.66, 95% CI = 3.97-11.18), proportional reporting ratio (PRR = 6.08, χ2 = 69.12), and empirical Bayes geometric mean (EBGM = 6.08, the lower 90% one-sided CI = 3.95). Warfarin showed the slightest association with AKI in oral anticoagulants, lower than any direct oral anticoagulants excluding apixaban. Edoxaban exhibited the highest potential renal risk among direct oral anticoagulants, with an ROR of 3.32 (95% CI = 2.95-3.72). The median time to AKI onset was 36 (IQR 7-205) days following the initiation of anticoagulation therapy, and most AKI cases occurred within the first month.

CONCLUSION

Particular attention should be directed toward monitoring renal function in individuals receiving anticoagulants, including warfarin and direct oral anticoagulants, as well as other anticoagulant agents. This diligence is particularly imperative within the first month after anticoagulant administration for individuals with a tendency for AKI.

Thrombin as a multi-functional enzyme. Focus on in vitro and in vivo effects

Thrombin is the central protease in the coagulation cascade and one of the most extensively studied of all enzymes. In addition to its recognised role in the coagulation cascade and haemostasis, thrombin is known to have multiple pleiotropic effects, which mostly have been shown only in in vitro studies: it plays a role in inflammation and cellular proliferation and displays a mitogen activity on smooth muscle cells and endothelial cells, predominantly by activation of angiogenesis. In vivo , thrombin effects were examined in animal models of intravenous or intraarterial thrombin infusion. An extensive literature search regarding in vivo data showed that i) thrombin administered as a bolus causes microembolism, ii) thrombin infused slowly at steady-state conditions (up to 1.6 U/kg/min) leads to bleeds but not to intravascular clotting, iii) large quantity of thrombin infused at low rates (0.05 U/kg/min) does not have any measurable effect, and iv) thrombin increases vascular permeability leading to tissue damage. Although several decades of research on thrombin functions have provided a framework for understanding the biology of thrombin, animal and human studies with use of newer laboratory techniques are still needed to confirm the pleiotropic thrombin functions shown in in vitro studies.