In vitro evaluation of anticoagulant therapy management when urgent percutaneous coronary intervention is required in rivaroxaban-treated patients.

We investigated in vitro the management of intraprocedural anticoagulation in patients requiring immediate percutaneous coronary intervention (PCI) while using regular direct oral anticoagulants (DOACs). Twenty-five patients taking 20 mg of rivaroxaban once daily comprised the study group, while five healthy volunteers included the control group. In the study group, a beginning (24 h after the last rivaroxaban dose) examination was performed. Then, the effects of basal and four different anticoagulant doses (50 IU/kg unfractionated heparin (UFH), 100 IU/kg UFH, 0.5 mg/kg enoxaparin, and 1 mg/kg enoxaparin) on coagulation parameters were investigated at the 4th and 12th h following rivaroxaban intake. The effects of four different anticoagulant doses were evaluated in the control group. The anticoagulant activity was assessed mainly by anti-factor Xa (anti-Xa) levels. Beginning anti-Xa levels were significantly higher in the study group than in the control group (0.69 ± 0.77 IU/mL vs. 0.20 ± 0.14 IU/mL; p < 0.05). The study group's 4th and 12th-h anti-Xa levels were significantly higher than the beginning level (1.96 ± 1.35 IU/mL vs. 0.69 ± 0.77 IU/mL; p < 0.001 and 0.94 ± 1.21 IU/mL vs. 0.69 ± 0.77 IU/mL; p < 0.05, respectively). Anti-Xa levels increased significantly in the study group with the addition of UFH and enoxaparin doses at the 4th and 12th h than the beginning (p < 0.001 at all doses). The safest anti-Xa level (from 0.94 ± 1.21 to 2.00 ± 1.02 IU/mL) was achieved 12 h after rivaroxaban with 0.5 mg/kg enoxaparin. Anticoagulant activity was sufficient for urgent PCI at the 4th h after rivaroxaban treatment, and additional anticoagulant administration may not be required at this time. Twelve hours after taking rivaroxaban, administering 0.5 mg/kg of enoxaparin may provide adequate and safe anticoagulant activity for immediate PCI. This experimental study result should confirm with clinical trials (NCT05541757).

Identification of Kukoamine A, Zeaxanthin, and Clexane as New Furin Inhibitors.

The endogenous protease furin is a key protein in many different diseases, such as cancer and infections. For this reason, a wide range of studies has focused on targeting furin from a therapeutic point of view. Our main objective consisted of identifying new compounds that could enlarge the furin inhibitor arsenal; secondarily, we assayed their adjuvant effect in combination with a known furin inhibitor, CMK, which avoids the SARS-CoV-2 S protein cleavage by means of that inhibition. Virtual screening was carried out to identify potential furin inhibitors. The inhibition of physiological and purified recombinant furin by screening selected compounds, Clexane, and these drugs in combination with CMK was assayed in fluorogenic tests by using a specific furin substrate. The effects of the selected inhibitors from virtual screening on cell viability (293T HEK cell line) were assayed by means of flow cytometry. Through virtual screening, Zeaxanthin and Kukoamine A were selected as the main potential furin inhibitors. In fluorogenic assays, these two compounds and Clexane inhibited both physiological and recombinant furin in a dose-dependent way. In addition, these compounds increased physiological furin inhibition by CMK, showing an adjuvant effect. In conclusion, we identified Kukoamine A, Zeaxanthin, and Clexane as new furin inhibitors. In addition, these drugs were able to increase furin inhibition by CMK, so they could also increase its efficiency when avoiding S protein proteolysis, which is essential for SARS-CoV-2 cell infection.

Release characteristics of enoxaparin sodium-loaded polymethylmethacrylate bone cement.

BACKGROUND: This study aimed to prepare the polymethylmethacrylate (PMMA) bone cement release system with different concentrations of enoxaparin sodium (ES) and to investigate the release characteristics of ES after loading into the PMMA bone cement. METHODS: In the experimental group, 40 g Palacos®R PMMA bone cement was loaded with various amount of ES 4000, 8000, 12,000, 16,000, 20,000, and 24,000 AXaIU, respectively. The control group was not loaded with ES. Scanning electron microscopy (SEM) was used to observe the surface microstructure of the bone cement in the two groups. In the experiment group, the mold was extracted continuously with pH7.4 Tris-HCL buffer for 10 days. The extract solution was collected every day and the anti-FXa potency was measured. The experiment design and statistical analysis were conducted using a quantitative response parallel line method. RESULTS: Under the SEM, it was observed that ES was filled in the pores of PMMA bone cement polymer structure and released from the pores after extraction. There was a burst effect of the release. The release amount of ES on the first day was 0.415, 0.858, 1.110, 1.564, 1.952, and 2.513, respectively, from the six groups with various ES loading amount of 4000, 8000, 12,000, 16,000, 20,000, and 24,000 AXaIU, all reaching the peak of release on the first day. The release decreased rapidly on the next day and entered the plateau phase on the fourth day. CONCLUSION: The prepared ES-PMMA bone cement has high application potential in orthopedic surgery. ES-PMMA bone cement shows good drug release characteristics. The released enoxaparin sodium has a local anti-coagulant effect within 24 h after application, but it will not be released for a long time, which is complementary to postoperative anti-coagulation therapy.

Effective Inhibition of SARS-CoV-2 Entry by Heparin and Enoxaparin Derivatives.

Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) has caused a pandemic of historic proportions and continues to spread globally, with enormous consequences to human health. Currently there is no vaccine, effective therapeutic, or prophylactic. As with other betacoronaviruses, attachment and entry of SARS-CoV-2 are mediated by the spike glycoprotein (SGP). In addition to its well-documented interaction with its receptor, human angiotensin-converting enzyme 2 (hACE2), SGP has been found to bind to glycosaminoglycans like heparan sulfate, which is found on the surface of virtually all mammalian cells. Here, we pseudotyped SARS-CoV-2 SGP on a third-generation lentiviral (pLV) vector and tested the impact of various sulfated polysaccharides on transduction efficiency in mammalian cells. The pLV vector pseudotyped SGP efficiently and produced high titers on HEK293T cells. Various sulfated polysaccharides potently neutralized pLV-S pseudotyped virus with clear structure-based differences in antiviral activity and affinity to SGP. Concentration-response curves showed that pLV-S particles were efficiently neutralized by a range of concentrations of unfractionated heparin (UFH), enoxaparin, 6-O-desulfated UFH, and 6-O-desulfated enoxaparin with 50% inhibitory concentrations (IC50s) of 5.99 µg/liter, 1.08 mg/liter, 1.77 µg/liter, and 5.86 mg/liter, respectively. In summary, several sulfated polysaccharides show potent anti-SARS-CoV-2 activity and can be developed for prophylactic as well as therapeutic purposes.IMPORTANCE The emergence of severe acute respiratory syndrome coronavirus (SARS-CoV-2) in Wuhan, China, in late 2019 and its subsequent spread to the rest of the world has created a pandemic situation unprecedented in modern history. While ACE2 has been identified as the viral receptor, cellular polysaccharides have also been implicated in virus entry. The SARS-CoV-2 spike glycoprotein (SGP) binds to glycosaminoglycans like heparan sulfate, which is found on the surface of virtually all mammalian cells. Here, we report structure-based differences in antiviral activity and affinity to SGP for several sulfated polysaccharides, including both well-characterized FDA-approved drugs and novel marine sulfated polysaccharides, which can be developed for prophylactic as well as therapeutic purposes.

Supplementation with antithrombin III ex vivo optimizes enoxaparin responses in critically injured patients.

BACKGROUND: The high incidence of venous thromboembolism (VTE) following trauma persists in spite of aggressive thromboprophylaxis strategies. Approximately half of VTE patients do not achieve the recommended anti-FXa response to enoxaparin anticoagulation (0.1-0.4 IU/mL), however, research to explain or correct this phenomenon is lacking. We hypothesized that antithrombin III (AT) deficiency is associated with poor enoxaparin responsiveness in trauma patients that develop VTE which can be reversed through supplementation with AT. METHODS AND FINDINGS: A retrospective cohort study was performed on plasma collected from trauma patients who did and did not develop pulmonary embolism (PE) as well as healthy volunteers. AT levels, thrombin generation, and anti-FXa levels were measured in the collected plasma at baseline and in response to supplementation with AT concentrate at 120-200% or plasma (30% volume). A total of 54 PE patients and 46 non-PE patients were enrolled in this study for analysis. Compared to healthy volunteers, trauma patients had lower levels of AT, elevated thrombin generation, and lower anti-FXa levels in response to enoxaparin. Moreover, thrombin generation was higher and responses to enoxaparin were lower in patients who developed PE compared to those who did not develop PE. We found that supplementation with AT, but not plasma, increased AT levels and improved enoxaparin-mediated inhibition of thrombin generation. CONCLUSIONS: Supplementation with AT may provide a novel adjunct therapy to increase the effectiveness of enoxaparin thromboprophylaxis and reduce the incidence of VTE in the trauma population.

Fish oil attenuates neurologic severity of antiphospholipid syndrome in a mice experimental model.

INTRODUCTION: Murine experimental models of antiphospholipid syndrome (eAPLS) showed neurologic dysfunction and therapeutic effect of the anticoagulant enoxaparin is well established. Omega-3 fatty acids and curcumin, tested in neuroinflammation and auto-immunity diseases, might be interesting therapeutic candidates. The aim of this study was to evaluate the effects of these candidates on neurologic severity in eAPLS. METHODS: One month after immunization of BALB/c mice with beta-2-glycoprotein I, daily treatments were initiated with enoxaparin (1 mg/kg), omega-3 fatty acids (0.5 g/kg), and curcumin (200 mg/kg) for 3 months. RESULTS: Mortality was significantly decreased by enoxaparin and omega-3 treatments. Fish oil and curcumin group exhibited the highest mean of swimming behavior in forced swim test in surviving mice. Mice under omega-3 fatty acids or curcumin presented low anxiety-like behavior in the elevated plus-maze test. Cerebral histopathology revealed heavy inflammatory infiltrates in cortical and subcortical regions with vacuolization, swelling, and degeneration of astrocytes in the control group, with aggravation under curcumin; no infiltrate was retrieved in enoxaparin and omega-3 groups. CONCLUSION: Our study is the first to demonstrate a potential therapeutic effect of omega-3 fatty acids in eAPLS. Enoxaparin and omega-3 fatty acids combination would be interesting for further investigation.

Molecular docking based virtual screening of natural compounds as potential BACE1 inhibitors: 3D QSAR pharmacophore mapping and molecular dynamics analysis.

Beta-site APP cleaving enzyme1 (BACE1) catalyzes the rate determining step in the generation of Aß peptide and is widely considered as a potential therapeutic drug target for Alzheimer's disease (AD). Active site of BACE1 contains catalytic aspartic (Asp) dyad and flap. Asp dyad cleaves the substrate amyloid precursor protein with the help of flap. Currently, there are no marketed drugs available against BACE1 and existing inhibitors are mostly pseudopeptide or synthetic derivatives. There is a need to search for a potent inhibitor with natural scaffold interacting with flap and Asp dyad. This study screens the natural database InterBioScreen, followed by three-dimensional (3D) QSAR pharmacophore modeling, mapping, in silico ADME/T predictions to find the potential BACE1 inhibitors. Further, molecular dynamics of selected inhibitors were performed to observe the dynamic structure of protein after ligand binding. All conformations and the residues of binding region were stable but the flap adopted a closed conformation after binding with the ligand. Bond oligosaccharide interacted with the flap as well as catalytic dyad via hydrogen bond throughout the simulation. This led to stabilize the flap in closed conformation and restricted the entry of substrate. Carbohydrates have been earlier used in the treatment of AD because of their low toxicity, high efficiency, good biocompatibility, and easy permeability through the blood-brain barrier. Our finding will be helpful in identify the potential leads to design novel BACE1 inhibitors for AD therapy.

Investigation of possible prophylactic, renoprotective, and cardioprotective effects of thromboprophylactic drugs against ischemia-reperfusion injury.

The aim of this study was to investigate whether anticoagulant and antiaggregant agents have protective effects against oxidative damage induced by peripheral ischemia-reperfusion (I/R). Groups were created as follows: control group, I/R group (sham group), I/R plus acetylsalicylic acid (Group I), I/R+clopidogrel (Group II), I/R+rivaroxaban (Group III), I/R+bemiparin sodium (Group IV), and I/R+enoxaparin sodium (Group V). In Groups I, II, III, IV, and V, drugs were administered daily for 1 week before I/R creation. Peripheral I/R was induced in the I/R groups by clamping the right femoral artery. The rats were sacrificed 1 hour after reperfusion. Nitrogen oxide levels, malondialdehyde (MDA) levels, paraoxonase-1 (PON1) activity, and prolidase activity were evaluated in both cardiac and renal tissues. There was no significant difference in nitrogen oxide levels between the groups. However, cardiac and renal MDA were significantly higher and PON1 activity was markedly lower in the I/R groups compared with the control group (p<0.05). Although elevated prolidase activity was detected in both the cardiac and renal tissue of the I/R groups, only the sham group and Group V had significantly higher renal prolidase activity (p<0.05). Group V had significantly higher cardiac MDA, PON1, prolidase levels, and renal prolidase activity compared with the sham group (p<0.05). Significant improvement in renal MDA levels was only observed in Group III, and marked improvement was observed in the cardiac MDA levels of Group II when compared with the sham group (p<0.05). Thromboprophylactic agents appear to provide partial or prominent protection against I/R injury.

Vitamin D reverses aPL-induced inflammation and LMWH-induced sFlt-1 release by human trophoblast.

PROBLEM: Women with antiphospholipid syndrome (APS) are at increased risk of recurrent pregnancy loss (RPL) and preeclampsia. Antiphospholipid antibodies (aPL) directly alter trophoblast function. Treatment with low molecular weight heparin (LMWH) reduces the risk of RPL but not preeclampsia. Moreover, LMWH stimulates trophoblast sFlt-1 release, an anti-angiogenic factor associated with preeclampsia. Since vitamin D deficiency is associated with APS and preeclampsia, this study sought to determine the effect of vitamin D on trophoblast function in the setting of aPL and LMWH. METHOD OF STUDY: A human first trimester trophoblast cell line (HTR8) and primary trophoblast cultures were treated with or without aPL in the presence and absence of vitamin D, LMWH or both. Trophoblast secretion of inflammatory cytokines and angiogenic factors were measured by ELISA. RESULTS: Vitamin D alone or in combination with LMWH attenuated the aPL-induced trophoblast inflammatory response in the HTR8 cells and primary cultures. While vitamin D did not have any impact on aPL-mediated modulation of angiogenic factors in the primary trophoblast, it significantly inhibited LMWH-induced sFlt-1 release. CONCLUSION: LMWH in combination with vitamin D may be more beneficial than single-agent therapy by preventing aPL-induced trophoblast inflammation and reversing LMWH-induced sFlt-1 secretion.

In vitro comparison of the novel, dual-acting FIIa/FXa-inhibitor EP217609C101, unfractionated heparin, enoxaparin, and fondaparinux in preventing cardiac catheter thrombosis.

Efficient and safe anticoagulation is crucial in patients requiring percutaneous coronary intervention (PCI) or extracorporeal circulation during cardiac surgery. Although new anticoagulant strategies have emerged for PCI as alternatives to the established treatment with heparins, the development of new anticoagulants with an improved efficacy/safety ratio is still necessary. Our study compared the efficacy of the novel, dual-acting, neutralizable FIIa/FXa-inhibitor EP217609C101 (EP) at 2, 1.2, 0.9, and 0.6 µg/ml to unfractionated heparin (UFH), enoxaparin, and fondaparinux in preventing cardiac catheter thrombosis under in vitro conditions. Blood drawn by venepunction from healthy male volunteers (n = 10) pretreated with 500 mg aspirin orally was treated with the anticoagulant to test and continuously circulated through a cardiac catheter for 60 min or until the catheter became blocked by thrombotic debris. Anticoagulant efficacy was assessed by thrombus weight, electron microscopic features of the developing thrombi, and laboratory parameters. Whereas UFH, enoxaparin, EP 2, and EP 1.2 µg/ml secured maximum circulation times, statistically significant premature catheter occlusions were observed for EP 0.9, EP 0.6 µg/ml, and fondaparinux. The UFH group and both high-dose concentrations of EP showed significantly lower thrombus weights than the low-dose concentrations of EP and fondaparinux, (p ≤ 0.05). On electron microscopic analysis of the thrombotic debris no differences were observed in erythrocyte deposition between UFH, enoxaparin, and all EP concentrations tested. A significant reduction in fibrin deposition was achieved by UFH and EP 2 µg/ml but no significant differences in platelet deposition were found, except for a significant reduction for EP 0.6 µg/ml. Our in vitro study showed that EP217609C101 is a promising new drug that is dose-dependently superior to classical (UFH, enoxaparin) and newer (fondaparinux) drugs in preventing heart catheter thrombosis.

Effect of enoxaparin and onion extract on human skin fibroblast cell line - therapeutic implications for the treatment of keloids.

CONTEXT: Keloids and hypertrophic scars are hyperproliferative skin disorders resulting in abnormal wound healing. In the prevention and treatment of keloids and hypertrophic scars, ointments containing heparin and onion extract are very popular. Their therapeutic effects, however, are still controversial and the mechanism of action is not fully understood. OBJECTIVE: The aim of this study was to assess the effect of enoxaparin and dry onion extract on proliferation, apoptosis and ß1 integrin expression in human fibroblasts. MATERIALS AND METHODS: Fibroblast human cell lines (46 BR.1 N) were treated for 48 h with various concentrations of enoxaparin sodium (20, 100, 500 µg/mL) and/or onion [Allium cepa L. (Alliaceae)] extract (50, 250, 1000 µg/mL). The cell proliferation was evaluated by [(3)H]-thymidine incorporation assay. Furthermore, the expression of ß1 integrin and apoptosis was determined by flow cytometry. RESULTS AND DISCUSSION: The results demonstrate that enoxaparin and onion extract inhibited the proliferation of human fibroblasts. Almost complete inhibition of cell proliferation was achieved by enoxaparin in 500 µg/mL concentration (91.5% reduction). The onion extract at a concentration of 250 µg/mL also strongly inhibited the proliferation of cells (50.8% reduction). Depending on concentration, enoxaparin and onion extract induced apoptosis (500 and 1000 µg/mL, respectively) and, depending on concentration, downregulated the expression of ß1 integrin on human fibroblasts. CONCLUSION: This work points at possible mechanism of action of enoxaparin and onion extract, when administered in the treatment of patients with keloids and hypertrophic scars.

Evaluation of the effects of hyperbaric oxygen treatment and enoxaparin on left colon anastomosis. An experimental study.

BACKGROUND: Surgical interventions on left colon lead to high morbidity. The problems in wound healing are the main cause of this morbidity. Hypoxia retards wound healing and hyperbaric oxygen treatment (HBOT) has an anti-hypoxic effect. MATERIALS AND METHODS: In this experimental study we divided eighty Wistar albino rats into eight groups and numbered between 1 and 8. Normal (non-ischemic) and ischemic left colon anastomosis were performed in the first and second four groups respectively. HBOT and subcutaneous enoxaparin were applied to the groups separately and in combination for four days, except the control groups. (Group-1 and Group-5). We measured anastomotic bursting pressures and performed pathological examinations besides electron microscopic study in one sample from each group after sacrificing the rats on the fourth day. RESULTS: There were no statistically significant differences in bursting pressures when we compared Group-1 with other non-ischemic groups, and Group-5 with Group-6, but there were statistically significant differences when we compared Group-5 with Group-7 and 8. In pathological examination, there were no statistically significant differences between the groups concerning necrosis, epithelization, granulation tissue formation and collagen deposition. Statistically significant differences were found in the scores of neovascularization when we compared Group-1 with Group-3 and 4, and Group-5 with Group-8. Electron microscopic evaluation revealed a prominent increase both in neovascularization and collagen fibers in the samples taken from the groups received enoxaparine and hyperbaric oxygen treatment in combination. CONCLUSIONS: These findings suggest that HBOT increases neovascularization and bursting pressures in ischemic colon anastomosis in contrast with enoxaparin.

Ion exchange chromatographic separation and isolation of oligosaccharides of intact low-molecular-weight heparin for the determination of their anticoagulant and anti-inflammatory properties.

It is well known that enoxaparin, a widely used anticoagulant and low-molecular-weight heparin containing a large number of oligosaccharides, possesses anti-inflammatory activity. Whilst enoxaparin has shown promising results in various inflammatory disorders, some of its oligosaccharides have anti-inflammatory properties and others increase the risk of bleeding due to their anticoagulant effects. The aim of this study was to develop an effective ion exchange chromatographic (IC) technique which allows the separation, isolation and, consequently, the identification of different oligosaccharides of enoxaparin with or without anticoagulant activity. The developed method utilises a semi-preparative CarboPac PA100 (9 × 250 mm) ion exchange column with sodium chloride gradient elution and UV detection at 232 nm. The method successfully resolved enoxaparin into more than 30 different peaks. IC-derived oligosaccharides with high, moderate, low or no anticoagulant activity were identified using an anti-factor Xa assay. The anti-inflammatory activity of selected oligosaccharides was investigated using the Griess assay. Using this technique, the oligosaccharides of enoxaparin with low or no anticoagulant activity, whilst exhibiting significant anti-inflammatory activity, could be fractionated. This technique can provide a platform to identify the oligosaccharides which are devoid of significant anticoagulant activity and are responsible for the therapeutic effects of enoxaparin that have been observed in various inflammatory conditions.

Effects of low molecular weight heparins and unfractionated heparin on viability of human umbilical vein endothelial cells.

AIM: The aim of this study was to investigate the effects of bemiparin, nadroparin, enoxaparin, and heparin on viability of human umbilical vein endothelial cells (HUVEC). METHODS: Cultivation of HUVEC was performed in an incubator having 5 % CO(2) at 37 °C and with predefined supplemented medium, until cell monolayers attained confluence which occurred after 7 days. The assays were performed in the exponential growth phase of the cells. The cell viability was assessed using the cleavage of tetrazolium salts added to the culture medium. Heparin sodium, enoxaparin sodium, bemiparin sodium, and nadroparin calcium with concentrations of 100, 10, and 1 IU/100 µL were used for the proliferation assay in which cells were incubated for 24, 48, and 72 h with these drugs. The experiments were conducted in four replicates. RESULTS: Among the study drugs with maximal concentration used in the experiments (100 IU/100 µL), heparin was found to be associated with the lowest viability score in 24 and 48 h, while bemiparin showed the lowest at 72 h. Bemiparin 100 IU/100 µL was significantly associated with lower viability score than that of bemiparin 10 IU/100 µL and bemiparin 1 IU/100 µL at every time interval. Among gradual concentrations of enoxaparin, however, concentration of 1 IU/100 µL was associated with the lowest viability scores at every time point. Heparin 1 IU/100 µL, nadroparin 100 IU/100 µL, and enoxaparin 100 IU/100 µL groups had the highest viability score after 72 h of incubation. CONCLUSION(S): Among low molecular weight heparins (LMWHs), 100 IU/100 µL concentration of bemiparin was associated with a more pronounced effect on reducing viability of HUVEC after 72 h of incubation, while nadroparin 100 IU/100 µL and enoxaparin 100 IU/100 µL showed the least effects. LMWHs differ both from each other and heparin with respect to their effects on cellular viability of HUVEC in dose- and time-dependent manner.

Concomitant use of medication with antiplatelet effects in patients receiving either rivaroxaban or enoxaparin after total hip or knee arthroplasty.

INTRODUCTION: The RECORD programme compared oral rivaroxaban with enoxaparin for prevention of venous thromboembolism after elective total hip or knee replacement. This analysis compared the safety of concomitant use of specified medications with rivaroxaban and enoxaparin by evaluating postoperative bleeding rates from the pooled RECORD1-4 data. MATERIALS AND METHODS: The co-medications were non-steroidal anti-inflammatory drugs and platelet function inhibitors, including acetylsalicylic acid (no dose restriction). The endpoints evaluated were the composite of major and non-major clinically relevant bleeding and any bleeding occurring after first oral study drug intake. The time relative to surgery was stratified into three time periods: day 1-3, day 4-7 and after day 7. Relative bleeding rate ratios for co-medication use versus non-use were derived using stratified Mantel-Haenszel methods and compared between rivaroxaban and enoxaparin groups. RESULTS: Co-medication use with rivaroxaban or enoxaparin resulted in non-significant increases in bleeding events. Respective rate ratios were not significantly different between rivaroxaban and enoxaparin for all bleeding endpoints with concomitant use of non-steroidal anti-inflammatory drugs (any bleeding, 1.22 vs 1.22; major and non-major clinically relevant bleeding, 1.28 vs 0.90) and with concomitant use of platelet function inhibitors/acetylsalicylic acid (any bleeding, 1.32 vs 1.40; major and non-major clinically relevant bleeding, 1.11 vs 1.13). CONCLUSIONS: This explorative analysis indicates that there is no significant increase in bleeding risk for rivaroxaban compared with enoxaparin when co-administered with non-steroidal anti-inflammatory drugs or acetylsalicylic acid, although, because of low usage, the experience with platelet function inhibitors (except acetylsalicylic acid) was limited.

Effects of nadroparin, enoxaparin, and unfractionated heparin on endogenous formation of factor Xa and IIa and on thrombelastometry profiles in cord versus adult blood.

BACKGROUND: To date, only few pharmacokinetic studies on low-molecular-weight heparins (LMWHs) in neonates exist not allowing to formally assess pharmacodynamics of LMWHs in neonates. OBJECTIVE: To evaluate the anticoagulant effects of the two LMWHs nadroparin and enoxaparin on endogenous formation of FXa or FIIa in cord versus adult platelet-poor plasma (PPP) and on thrombelastometry profiles in cord versus adult whole blood (WB). Unfractionated heparin (UH) was the reference antithrombotic drug. METHODS: The effects of nadroparin, enoxaparin, or UH on endogenous formation of FXa or FIIa was investigated in tissue factor-activated PPP using a subsampling technique and chromogenic substrates. The anticoagulant efficacy of these drugs was also investigated in WB triggered by the physiological relevant activator collagen/endogenous thrombin using thrombelastometry. RESULTS: The major findings are (i) nadroparin is as efficient as enoxaparin concerning inhibition of the endogenous formation of FXa and FIIa, (ii) cord PPP and WB are significantly more susceptible to the addition of LMWHs or UH than adult PPP or WB, and (iii) compared by equivalent anti-FXa activity, the anticoagulant action of UH is markedly higher than that of the LMWHs in PPP and WB of neonatal or adult origin. CONCLUSIONS: Administration of LMWHs in neonates has to be performed carefully to avoid bleeding side effects due to their high anticoagulant efficacy in cord PPP and WB.

High-dose tirofiban with enoxaparin and inflammatory markers in high-risk percutaneous intervention.

AIM: The study assessed the benefit of high bolus dose tirofiban (HD-tirofiban) with enoxaparin compared with HD-tirofiban with unfractionated heparin (UFH). The study examined markers of platelet activation, thrombin generation and inflammation. MATERIALS AND METHODS: The study is a prospective single centre open-label trial of patients with high-risk acute coronary syndrome treated with percutaneous intervention (PCI) who were randomized to anticoagulation with UFH or enoxaparin with HD-tirofiban (25 microg kg(-1) bolus). This study measured a panel of platelet activation markers, inflammatory biomarkers and thrombus generation between the two groups. RESULT: Sixty patients undergoing high-risk PCI were enroled in the study. Platelet inhibition as assessed by whole blood aggregometry following HD-tirofiban infusion was similar in both the UFH and enoxaparin groups. CD40 ligand expression on platelets was significantly reduced following PCI with HD-tirofiban and either UFH or enoxaparin. Following PCI, there were significant reductions measured in other markers of platelet activation including PAC-1, P selectin, factor V/Va, platelet-monocyte aggregates and monocyte expression of Mac-1 as determined by analysis of venous blood samples using flow cytometry. Prothrombin fragment 1+2, D-dimer, von Willebrand factor and high sensitive C-reactive protein levels were significantly less post PCI in the enoxaparin group compared with those patients receiving UFH. CONCLUSION: The combination of HD tirofiban with enoxaparin resulted in an attenuated inflammatory response when compared with that of the combination of HD tirofiban with UFH.

The efficacy of Ankaferd Blood Stopper in antithrombotic drug-induced primary and secondary hemostatic abnormalities of a rat-bleeding model.

Ankaferd comprises a standardized mixture of plants Thymus vulgaris, Glycyrrhiza glabra, Vitis vinifera, Alpinia officinarum and Urtica dioica. Ankaferd Blood Stopper (ABS) as a medicinal product has been approved in the management of external hemorrhage and dental surgery bleedings in Turkey. This study aimed to evaluate the in-vivo hemostatic effect of ABS in rats pretreated with acetylsalicylic acid or enoxaparin. Wistar rats (210-270 g) of both sexes were used in this study. The animals were pretreated with acetylsalicylic acid (10 mg/kg) orally for 4 days or enoxaparin sodium (8 mg/kg) subcutaneously for 3 days or did not receive any anticoagulant before tail cut at 4th day. ABS was administered topically [a total of 4 ml (1 ml/puff x 4)] to the cut tail in the studied animals. The duration of bleeding and the amount of bleeding were measured in order to evaluate the hemostatic effect of ABS. In acetylsalicylic acid-treated animals, topical ABS reduced both the duration and also the amount of bleeding volume by 68.4 and 54.6%, respectively. It was also effective in shortening the duration of bleeding (30.6%) and decreasing the amount of bleeding (32.8%) in enoxaparin-treated animals. ABS, a traditional folkloric medicinal plant extract, has in-vivo hemostatic actions, which may provide a therapeutic potential for the management of patients with deficient hemostasis in the clinical medicine.

Effects of enoxaparin and unfractionated heparin on platelet activity and reactivity during carotid endarterectomy.

The aim of this study was to determine platelet activity and reactivity and the effects of unfractionated heparin (UFH) and enoxaparin on platelet function during carotid eversion endarterectomy under local anesthesia. Twenty symptomatic patients undergoing carotid endarterectomy were randomly assigned to either 5,000 units of UFH or body weight-adjusted enoxaparin (0.5 mg/kg body weight) as an intraoperative intravenous bolus. The activity of platelets was assessed by measuring the expression of CD62p and CD41 with flow cytometry. Additionally, platelet-leukocyte aggregates (PLAs) were enumerated. The reactivity of platelets was evaluated by measuring the expression of the same antigens after stimulation. In addition, platelet reactivity was also analyzed using a PFA-100 analyzer. A significant increase in platelet activity was observed during surgery for CD41 and CD62p (p = .002 and < .001, respectively). The number of PLAs showed no significant changes during surgery. Yet there was a significant difference between patients treated with UFH and patients treated with enoxaparin. No difference for platelet activity or reactivity for patients receiving either UFH or enoxaparin prior to cross-clamping of the carotid arteries was seen. The formation of PLAs after endarterectomy was significantly higher in the UFH group; thus, PLAs are probably a useful surrogate parameter for measuring platelet activity.

Thrombin generation assays are superior to traditional tests in assessing anticoagulation reversal in vitro.

Even though new anticoagulants are being devised with the notion that they do not require regular monitoring, when bleeding occurs, it is important to have an antidote and a reliable test to confirm whether the anticoagulant effects are persisting. We examined the effects of five heparinoids, unfractionated heparin (UFH), tinzaparin, enoxaparin, danaparoid and fondaparinux on the traditional APTT and anti-Xa assays as well as on the calibrated automated thrombogram (CAT). We also studied the ability of protamine sulphate (PS), NovoSeven, FEIBA and FFP to reverse maximum anticoagulation induced by the different heparinoids. The CAT was the only test to detect the coagulopathy of all the anticoagulants. PS produced complete reversal of UFH, and this could be monitored with all three tests. Tinzaparin can also be completely neutralised in vitro with high doses of PS, but the maximum enoxaparin reversal achieved with PS is only approximately 60%. Fondaparinux does not significantly affect the APTT and PS has no significant effect on its reversal. Only NovoSeven was able to correct the fondaparinux induced CAT abnormalities whilst having no effect on the anti-Xa level. None of the reversal agents was very effective in danaparoid spiked plasma but NovoSeven, at high dose, increased the ETP by 40% and reduced the anti-Xa level from 0.93 to 0.78 IU/ml. We conclude that the CAT is superior to the traditional coagulation tests in that it not only detects the coagulopathy of all the heparinoids but can be also be used to monitor their reversal.