Assessing Direct Oral Anticoagulants in the Clinical Laboratory.

Direct oral anticoagulants (DOACs) have significant advantages over vitamin K antagonists including lack of need for routine laboratory monitoring. However, assessment of DOAC effect and concentration may be important to guide clinical management including need for DOAC reversal, particularly in acute or emergent situations. In this manuscript, the authors describe tests to screen for DOAC presence and tests that have demonstrated equivalence to gold standard testing for quantifying DOAC exposure. They also discuss the effect of DOACs on other coagulation assays and strategies for monitoring unfractionated heparin in patients with concomitant DOAC exposure.

Risk of ocular neovascular conversion and systemic bleeding complications in patients with AMD on DOACs or Warfarin.

PURPOSE: Conversion to neovascular disease in patients with non-neovascular age-related macular degeneration (AMD) initiated on direct oral anticoagulants (DOAC) compared to matched patients treated with warfarin. DESIGN: Retrospective cohort study. SUBJECTS, PARTICIPANTS, AND/OR CONTROLS: The study included 20,300 patients and 13,387 patients with non-neovascular AMD initiated on DOACs or warfarin, respectively, before propensity score matching (PSM). METHODS, INTERVENTION, OR TESTING: TriNetX (Cambridge, MA, USA), was used to identify patients diagnosed with non-neovascular AMD stratified by treatment with DOACs or warfarin with at least six months of follow-up. Propensity score matching was performed to control for baseline demographics and medical comorbidities. MAIN OUTCOME MEASURES: Relative risk (RR) of developing neovascular AMD, macular hemorrhage (MH), vitreous hemorrhage (VH), and requiring an ocular intervention (intravitreal anti-vascular endothelial growth factor (VEGF) therapy or pars plana vitrectomy (PPV)) within six months and one year. Patients with chronic atrial fibrillation (AF) on anticoagulation were separately evaluated for the same measures within 5 years after initiating therapy. RESULTS: Treatment with warfarin was associated with higher risk of developing neovascular AMD at six months (RR,1.24, 95% CI, 1.12 - 1.39; P<.001) and one year (RR, 1.26, 95% CI, 1.14 - 1.40; P<.001) when compared to matched patients treated with DOACs. There was an increased risk of requiring intravitreal anti-VEGF therapy (6 months: RR, 1.30; 95% CI, 1.13-1.49; P<.001; 1 year: RR, 1.31, 95% CI, 0.72 - 2.05; P<.001) and PPV (6 months: RR, 1.16; 95% CI, 1.16-3.94; P = .01; 1 year: RR, 2.29, 95% CI, 1.30 - 4.05; P=.003). Among patients with AMD and AF treated with warfarin, there was an increased risk of ocular complications (neovascular AMD: RR, 1.25; 95% CI, 1.14-1.38; P<.001; MH: RR, 1.86; 95% CI, 1.47-2.35; P<.001; VH: RR, 2.22; 95% CI, 1.51-3.26; P<.001) and need for intravitreal anti-VEGF therapy (RR, 1.34; 95% CI, 1.18-1.52; P<.001) over an extended 5-year period. There was no significant difference in the development of major systemic hemorrhagic events between the two cohorts over five years. CONCLUSIONS: Patients with non-neovascular AMD treated with warfarin were more likely to develop neovascular disease and require ocular intervention for hemorrhagic complications when compared to matched patients initiated on DOACs.

Knowledge, Attitude and Practice Toward Intracerebral Hemorrhage Prevention Among Patients Taking Oral Anticoagulants.

Background: Intracerebral hemorrhage (ICH) affects up to 1% of chronic oral anticoagulation (OAC) users per year. This study explored the knowledge, attitude and practice (KAP) towards ICH prevention among patients taking OACs. Methods: This multicenter cross-sectional survey was conducted at 4 hospitals from February to May 2023, and a self-administered questionnaire was developed to assess KAP toward ICH prevention among patients taking OACs. Structural equation modeling was used to assess the relationship between KAP. Results: A total of 536 valid questionnaires (67.25%) were analyzed, from 43.8% participants on Warfarin, 40.5% on Rivaroxaban and 15.7% on Dabigatran. The average knowledge, attitudes and practice scores were 9.22, 24.11, and 28.01 out of 16, 35 and 40, respectively. Participants who received Rivaroxaban had lower knowledge scores but higher attitude and practice store compared to those who received Warfarin or Dabigatran (all p < 0.001). According to Structure Equation Modeling, attitude had direct positive effect on practice (ß = 0.694 [0.603-0.804], p = 0.012), while knowledge had direct negative effect on attitude (ß = -2.077 [-2.507-1.651], p = 0.013), as well as negative effect on practice, both direct (ß = -0.450[-0.689-2.03], p=0.012), and indirect (ß = -1.441 [-1.928-1.192], p = 0.004). Conclusion: Patients taking OACs showed insufficient knowledge, negative attitude and proactive practice regarding ICH; practice scores were affected by age, type of anticoagulation medication, and attitude rather than knowledge.

Dual benefits of NBD-Cl fluorogenic action and sample pretreatment (SALLE) technology in the assessment of anticoagulant medication: Dabigatran in pharmaceutical capsules and plasma samples.

Dabigatran (DBG), marketed as Pradaxa, is an anticoagulant medication prescribed for the treatment and mitigation of blood clots and to lower the risk of stroke in individuals with the heart condition known as atrial fibrillation. This medication is specifically indicated for preventing blood clots post hip or knee replacement surgeries and in patients with a prior history of clots. Compared to warfarin, dabigatran serves as a viable alternative that does not necessitate routine blood monitoring tests. The complimentary benefits associated with SALL (salting-out assisted liquid-liquid extraction) and the fluorogenic capabilities of benzofurazan. These methods were combined to provide an affordable and sensitive DBG assaying method. The spectral strength of the yellow luminous product was examined at 533.8 nm and by adjustment of a wavelength of 474.7 nm for excitation. To assess its linearity, the calibration chart was tested across a DBG concentration range of 30-500 ng/ml. Via accurate computation based on ICH, the detection limit (LD) was determined to be 9.5 ng/ml, and the strategy can quantify the DBG to a limit of 28 ng/ml. To ensure success, various crucial parameters for method implementation have been extensively studied and adapted. The validation of the strategy adhered to the policies outlined by ICH, affirming its precision in quantifying DBG in capsules. Furthermore, the inclusion of SALLE steps facilitated accurate monitoring of DBG in plasma samples, introducing a unique and advanced methodology for analyzing this compound in biological samples.

Genetic variants of ABCB1 and CES1 genes on dabigatran metabolism in the Kazakh population.

Background: Allelic variants of genes encoding enzymes of the esterase system (CES1) and P-glycoprotein (ABCB1) can change the metabolism and pharmacokinetics of dabigatran. Therefore, they act as determining factors in the development of side effects, especially bleeding. We analyzed the genotype-phenotype relationship of ABCB1 (rs1045642, rs4148738, rs2032582, and rs1128503) and CES1 (rs8192935, rs71647871, and rs2244613) polymorphisms in patients with atrial fibrillation who had been treated with dabigatran. Methods: A total of 150 patients were recruited for this study. TaqMan technology was used for SNP genotyping. Results: Patients with the rs2244613 GG genotype had a lower concentration (55.27 ± 34.22 ng/ml) compared to those with the TT genotype (63.33 ± 52.25 ng/ml) (additive model, P = 0.000). Individuals with the rs8192935 AA genotype had a lower concentration (52.72 ± 30.45 ng/ml) compared to those with the GG genotype (79.78 ± 57 ng/ml) (additive model, P = 0.001). The APTT values among the different genotypes of the ABCB1 SNPs, rs4148738 and rs1045642, were significantly different (P = 0.035 and P = 0.024, respectively). Conclusion: Our research demonstrates that the CES1 polymorphisms, rs8192935 and rs2244613, are associated with the pharmacodynamics and pharmacokinetics of dabigatran in the Kazakh subpopulation.

Effectiveness of Novel Oral Anticoagulants Versus Warfarin in Patients With Atrial Fibrillation: A Systematic Review and Meta-Analysis.

Atrial fibrillation (AF) is a common cardiac arrhythmia associated with an increased risk of stroke and systemic embolism (SE). Anticoagulation therapy, particularly with vitamin K antagonists (VKA) or novel oral anticoagulants (NOACs), is essential for stroke prevention in patients with AF. However, the comparative effectiveness of NOACs and warfarin remains debatable. Of the 34 studies included, 14 studies involving 166,845 patients were included in the meta-analysis and 20 studies were included in the systematic review. Our findings indicate that NOACs were associated with a significantly lesser risk of stroke/SE with a relative risk (RR) of 0.84 and p=0.0005, and all-cause mortality RR=0.88 and p=0.006. There were no significant differences between major bleeding events with an RR of 0.87 and p=0.22, and serious adverse events (SAE) with RR=1.01 and p=0.35, compared to warfarin in patients with AF. Our meta-analysis demonstrates strong evidence for the superiority in reducing stroke/SE and all-cause mortality of NOACs compared to warfarin. However, no significant differences were identified in the bleeding outcomes or SAEs between the two groups.

Comparison of warfarin, rivaroxaban, and dabigatran for effectiveness and safety in atrial fibrillation patients with different CHA2DS2-VASc scores: a retrospective cohort study.

BACKGROUND: This retrospective cohort study aims to compare the effectiveness and safety of warfarin, rivaroxaban, and dabigatran in atrial fibrillation (AF) patients with different CHA2DS2-VASc scores in northern China. METHODS: A retrospective cohort study was performed to evaluate anticoagulation in AF patients at the second affiliated hospital of Harbin Medical University from September 2018 to August 2019. Patients included in this study (n = 806) received warfarin (n = 300), or rivaroxaban (n = 203), or dabigatran (n = 303). Baseline characteristics and follow-up data including adherence, bleeding events and ischemic stroke (IS) events were collected. RESULTS: Patients receiving rivaroxaban (73.9%) or dabigatran (73.6%) showed better adherence than those receiving warfarin (56.7%). Compared with warfarin-treated patients, dabigatran-treated patients had lower incidence of bleeding events (10.9% vs 19.3%, χ2 = 8.385, P = 0.004) and rivaroxaban-treated patients had lower incidence of major adverse cardiovascular events (7.4% vs 13.7%, χ2 = 4.822, P = 0.028). We classified patients into three groups based on CHA2DS2-VASc score (0-1, 2-3, ≥ 4). In dabigatran intervention, incidence of bleeding events was higher in patients with score 0-1 (20.0%) than those with score 2-3 (7.9%, χ2 = 5.772, P = 0.016) or score ≥ 4 (8.6%, χ2 = 4.682, P = 0.030). Patients with score 0-1 in warfarin or rivaroxaban therapy had a similar but not significant increase of bleeding compared with patients with score 2-3 or score ≥ 4, respectively. During the follow-up, 33 of 806 patients experienced IS and more than half (19, 57.6%) were patients with score ≥ 4. Comparing patients with score 0-1 and 2-3, the latter had an significant reduction of IS in patients prescribed warfarin and non-significant reduction in rivaroxaban and dabigatran therapy. CONCLUSION: Compared with warfarin therapy, patients with different CHA2DS2-VASc scores receiving either rivaroxaban or dabigatran were associated with higher persistence. AF patients with score ≥ 4 were more likely to experience IS events while hemorrhagic tendency preferred patients with low score 0-1.

Anticoagulation and Antiplatelet Regimen in Cardiac Transplant. Clinical Characteristics, Outcomes, and Blood Product Transfusion.

BACKGROUND: We aimed to evaluate the characteristics, clinical outcomes, and blood product transfusion (BPT) rates of patients undergoing cardiac transplant (CT) while receiving uninterrupted anticoagulation and antiplatelet therapy. METHODS: A retrospective, single-center, and observational study of adult patients who underwent CT was performed. Patients were classified into four groups: (1) patients without anticoagulation or antiplatelet therapy (control), (2) patients on antiplatelet therapy (AP), (3) patients on vitamin K antagonists (AVKs), and (4) patients on dabigatran (dabigatran). The primary endpoints were reoperation due to bleeding and perioperative BPT rates (packed red blood cells (PRBC), fresh frozen plasma, platelets). Secondary outcomes assessed included morbidity and mortality-related events. RESULTS: Of the 55 patients included, 6 (11%) received no therapy (control), 8 (15%) received antiplatelet therapy, 15 (27%) were on AVKs, and 26 (47%) were on dabigatran. There were no significant differences in the need for reoperation or other secondary morbidity-associated events. During surgery patients on dabigatran showed lower transfusion rates of PRBC (control 100%, AP 100%, AVKs 73%, dabigatran 50%, p = 0.011) and platelets (control 100%, AP 100%, AVKs 100%, dabigatran 69%, p = 0.019). The total intraoperative number of BPT was also the lowest in the dabigatran group (control 5.5 units, AP 5 units, AVKs 6 units, dabigatran 3 units; p = 0.038); receiving significantly less PRBC (control 2.5 units, AP 3 units, AVKs 2 units, dabigatran 0.5 units; p = 0.011). A Poisson multivariate analysis showed that only treatment on dabigatran reduces PRBC requirements during surgery, with an expected reduction of 64.5% (95% CI: 32.4%-81.4%). CONCLUSIONS: In patients listed for CT requiring anticoagulation due to nonvalvular atrial fibrillation, the use of dabigatran and its reversal with idarucizumab significantly reduces intraoperative BPT demand.

Differences in coagulation responses to vascular injury between uninterrupted dabigatran and apixaban - a clinical prospective randomized study.

BACKGROUND: The coagulation response during vascular injury with uninterrupted administration of direct oral anticoagulants (DOACs) has not been elucidated. OBJECTIVE: Our aim was to evaluate differences in coagulation responses after vascular injury between uninterrupted direct thrombin inhibitor and direct factor Xa inhibitor recipients. METHODS: Patients scheduled for catheter ablation for atrial fibrillation were randomly assigned to receive dabigatran or apixaban in this prospective, randomized, comparative, parallel-group study. Venous blood was collected three times: 180 minutes after taking the anticoagulant on the day before the procedure, before vascular punctures of the ablation procedure, and 10-15 minutes after the start of vascular punctures. RESULTS: Forty-two patients were enrolled. The prothrombin fragment 1+2 (F1+2) level, the primary endpoint, was much larger after vascular puncture in the uninterrupted dabigatran recipients (median: 83 pmol/L; interquartile range: 56-133 pmol/L) than in the uninterrupted apixaban recipients (median: 1 pmol/L; interquartile range: -3-19 pmol/L; P < 0.001). Antithrombin levels decreased after vascular puncture in dabigatran recipients, and both protein C and antithrombin levels decreased after vascular puncture in apixaban recipients. CONCLUSIONS: Unlike uninterrupted apixaban, uninterrupted dabigatran does not inhibit thrombin generation in response to vascular injury.

[Overdosing of direct oral anticoagulants]. / Überdosierung von direkten oralen Antikoagulanzien.

BACKGROUND: Direct oral anticoagulants (DOAC) are increasingly used for prophylaxis and treatment of thromboembolic events. Incorrectly dosed DOAC treatment is associated with excess mortality. PURPOSE: This article aims at raising awareness of DOAC overdosing and its causes as well as presenting a diagnostic and therapeutic work-up. MATERIAL AND METHODS: Based on a case presentation, a structured review of the current literature on DOAC overdosing was performed and treatment recommendations were extracted. RESULTS: In addition to wittingly or unwittingly increased DOAC intake, common causes of overdose are inadequate dose adjustment for concomitant medication or comorbidities. Global coagulation testing should be supplemented with DOAC-specific testing. Severe bleeding and the need for invasive diagnostics or urgent surgery represent indications for treating DOAC overdoses. Based on the cause of an DOAC overdose, active charcoal, endoscopic pill rescue, antagonization with idarucizumab or andexanet alfa and the targeted substitution of coagulation factors represent treatment options. CONCLUSION: The sensitization of clinicians is important to ensure a timely diagnosis and adequate treatment of DOAC overdosing. This report provides an overview of current knowledge on diagnostics and treatment; however, further studies are necessary to improve the existing algorithms.

Oral Anticoagulation Use in Individuals With Atrial Fibrillation and Chronic Kidney Disease: A Review.

Atrial fibrillation (AF) is highly prevalent in patients with chronic kidney disease (CKD). It is associated with an increased risk of stroke, which increases as kidney function declines. In the general population and in those with a moderate degree of CKD (creatinine clearance 30-50 mL/min), the use of oral anticoagulation to decrease the risk of stroke has been the standard of care based on a favorable risk-benefit profile that had been established in seminal randomized controlled trials. However, evidence regarding the use of oral anticoagulants for stroke prevention is less clear in patients with severe CKD (creatinine clearance <30 mL/min) and those receiving maintenance dialysis, as these individuals were excluded from such large randomized controlled trials. Nevertheless, the direct oral anticoagulants have invariably usurped vitamin K antagonists as the preferred choice for oral anticoagulation among patients with AF across all strata of CKD based on their well-defined safety and efficacy and multiple pharmacokinetic benefits (e.g., less drug-drug interactions). This review summarizes the current literature on the role of oral anticoagulation in the management of AF among patients with CKD and highlights current deficiencies in the evidence base and how to overcome them.

Role of a National Health Service Electronic Prescriptions Database in the Detection of Prescribing and Dispensing Issues and Adherence Evaluation of Direct Oral Anticoagulants.

BACKGROUND: Anticoagulation therapy plays a crucial role in the management of atrial fibrillation (AF) by significantly reducing the risk of stroke. Direct oral anticoagulants (DOAC) became preferred over warfarin due to their superior safety and efficacy profile. Assessing adherence to anticoagulation therapy is necessary in clinical practice for optimising patient outcomes and treatment efficacy, thus emphasising its significance. METHODS: A retrospective study utilised the Latvian National Health Service reimbursement prescriptions database, covering prescriptions for AF and flutter from January 2012 to December 2022. The proportion of days covered method was selected for adherence assessment, categorising it into three groups: (1) below 80%, (2) between 80% and 90%, and (3) above 90%. RESULTS: A total of 1,646,648 prescriptions were analysed. Dabigatran prescriptions started declining after 2020, coinciding with a decrease in warfarin prescriptions since 2018. The total adherence levels to DOAC therapy were 69.4%. Only 44.2% of users achieved an adherence level exceeding 80%. The rate of paper prescriptions decreased from 98.5% in 2017 to 1.3% in 2022. Additionally, the utilisation of international non-proprietary names reached 79.7% in 2022. Specifically, 16.7% of patients selected a single pharmacy, whereas 27.7% visited one or two pharmacies. Meanwhile, other patients obtained medicines from multiple pharmacies. CONCLUSIONS: The total adherence level to DOAC therapy is evaluated as low and there was no significant difference in age, gender, or "switcher" status among adherence groups. Physicians' prescribing habits have changed over a decade.

Is There an Alternative Oral Anticoagulation to Vitamin-K-Antagonists for Patients with Mechanical Aortic Valve Replacement? - A Literature Review.

Current guidelines exclusively recommend vitamin-K-antagonists (VKA) as anticoagulation for patients after mechanical aortic valve replacement due to the increased postoperative risk of valve thrombosis and thrombo-embolism. Strict and regular assessments are mandatory during VKA therapy to ensure a potent anticoagulatory effect within the desired range. From the patients' perspective, VKA are associated with relevant interactions and side effects reducing the quality of life and contributing to a high number of patients not achieving the optimal therapeutic target. Direct oral anticoagulants (DOAC) have replaced VKA therapy in the past for several indications, e.g., atrial fibrillation. However, it is still unclear if DOACs could replace VKA therapy in patients after mechanical aortic valve replacement. While the PROACT-Xa study did not show a sufficient anticoagulatory effect of apixaban plus aspirin compared to VKA therapy in patients after mechanical aortic valve replacement, the direct thrombin inhibitor dabigatran and the oral factor Xa inhibitors apixaban and rivaroxaban showed promising results in comparable patient cohorts in smaller studies and case reports. Factor Xa inhibitors were able to prevent thrombosis and thrombo-embolic events in patients after mechanical aortic valve replacement. Therefore, factor Xa inhibitors or factor XI inhibitors could provide a potent alternative to VKA for patients after a mechanical aortic valve replacement.

Role of CES1 and ABCB1 Genetic Polymorphisms on Functional Response to Dabigatran in Patients with Atrial Fibrillation.

Background: Dabigatran etexilate is a pro-drug hydrolyzed into dabigatran by carboxylesterases (CES) and is a substrate of the P-Glycoprotein encoded by the adenosine-triphosphate-binding cassette sub-family B member (ABCB)1 genes. We evaluated the functional response to dabigatran according to different CES1 and ABCB1 single-nucleotide polymorphisms (SNPs) in patients with atrial fibrillation (AF). Methods: A total of 100 consecutive patients with AF taking dabigatran were enrolled by two Italian centers. A venous blood sample was drawn for genetic determinations, as well as a measurement of the diluted thrombin time (dTT) and drug plasma concentrations, at the trough and peak. The main objective was the relationship between the dTT values and CES1 rs2244613, CES1 rs8192935 and ABCB1 rs4148738 SNP while on two different dabigatran doses (110 and 150 mg BID). Results: A total of 43 patients were on a 110 mg dabigatran dose and 57 on 150 mg. The DTT values at the trough and at peak were not different among patients with different CES1 rs2244613 and CES1 rs8192935 genotypes, regardless of the dabigatran dose. In patients on 150 mg dabigatran, the dTT values at the trough were 77 (44-111) ng/mL in patients with the ABCB1 rs4148738 heterozygous CT genotype vs. 127 (85-147) ng/mL in the wild-type CC genotype vs. 110 (47-159) ng/mL in the mutant trait TT genotype (p = 0.048). In patients with the ABCB1 rs4148738 CT genotype, OR for having dTT values at a trough below the median was 3.21, 95% CI 1.04-9.88 (p = 0.042). Conclusions: ABCB1 rs4148738 CT heterozygous is associated with the reduced anticoagulant activity of dabigatran at the trough in patients receiving the higher dose regimen.

Gene polymorphism as a cause of hemorrhagic complications in patients with non-valvular atrial fibrillation treated with oral vitamin K-independent anticoagulants.

Atrial fibrillation (AF) accounts for 40% of all cardiac arrhythmias and is associated with a high risk of stroke and systemic thromboembolic complications. Dabigatran, rivaroxaban, apixaban, and edoxaban are direct oral anticoagulants (DOACs) that have been proven to prevent stroke in patients with non-valvular AF. This review summarizes the pharmacokinetics, pharmacodynamics, and drug interactions of DOACs, as well as new data from pharmacogenetic studies of these drugs. This review is aimed at analyzing the scientific literature on the gene polymorphisms involved in the metabolism of DOACs. We searched PubMed, Cochrane, Google Scholar, and CyberLeninka (Russian version) databases with keywords: 'dabigatran', 'apixaban', 'rivaroxaban', 'edoxaban', 'gene polymorphism', 'pharmacogenetics', 'ABCB1', 'CES1', 'SULT1A', 'ABCG2', and 'CYP3A4'. The articles referred for this review include (1) full-text articles; (2) study design with meta-analysis, an observational study in patients taking DOAC; and (3) data on the single-nucleotide polymorphisms and kinetic parameters of DOACs (plasma concentration), or a particular clinical outcome, published in English and Russian languages during the last 10 years. The ages of the patients ranged from 18 to 75 years. Out of 114 reviewed works, 24 were found eligible. As per the available pharmacogenomic data, polymorphisms affecting DOACs are different. This may aid in developing individual approaches to optimize DOAC pharmacotherapy to reduce the risk of hemorrhagic complications. However, large-scale population studies are required to determine the dosage of the new oral anticoagulants based on genotyping. Information on the genetic effects is limited owing to the lack of large-scale studies. Uncovering the mechanisms of the genetic basis of sensitivity to DOACs helps in developing personalized therapy based on patient-specific genetic variants and improves the efficacy and safety of DOACs in the general population.

Gene polymorphism as a cause of hemorrhagic complications in patients with non-valvular atrial fibrillation treated with oral vitamin K-independent anticoagulantsAtrial fibrillation (AF) accounts for 40% of all cardiac arrhythmias and is associated with a high risk of stroke and systemic thromboembolic complications. Dabigatran, rivaroxaban, apixaban, and edoxaban are direct oral anticoagulants (DOACs) that have been proven to prevent stroke in patients with non-valvular AF. This review summarizes the pharmacokinetics, pharmacodynamics, and drug interactions of DOACs, as well as new data from pharmacogenetic studies of these drugs.

Efficacy and Safety of Direct Oral Anticoagulants Versus Warfarin in Saudi Patients With Atrial Fibrillation.

INTRODUCTION: Atrial fibrillation (AF) significantly heightens stroke risk, which can be mitigated through anticoagulation therapy. Although warfarin was traditionally employed for this purpose, the use of direct-acting oral anticoagulants (DOACs) is on the rise. METHODS: This retrospective study, which spanned from June 2016 to January 2018, focused on adult patients diagnosed with AF. Their treatments, either via warfarin or DOACs (apixaban, rivaroxaban, and dabigatran), were evaluated. Data analysis was done using Statistical Product and Service Solutions (SPSS, version 21; IBM SPSS Statistics for Windows, Armonk, NY). This study aims to evaluate the safety and effectiveness of DOACs versus warfarin in preventing thromboembolic complications among Saudi patients with AF. RESULTS: A total of 396 patients with AF, averaging 66 ± 14 years of age, were part of the study. Among them, there were slightly more female patients (205 or 51.8%). The majority of patients (223 or 56.3%) were treated with a DOAC, while the rest (173 or 43.7%) received warfarin. Furthermore, 93 patients (23.5%) were taking anti-platelet drugs. Statistically, the rate of ischemic stroke was significantly higher among patients treated with DOACs than with warfarin (p=0.005), but bleeding rates were similar in both groups. Specifically, the DOACs apixaban and rivaroxaban showed a significant association with the occurrence of stroke when compared to warfarin (p=0.012 and p=007, respectively). CONCLUSION: Overall, both DOACs and warfarin presented similar results regarding hemorrhagic complications when treating AF patients. However, the DOACs apixaban and rivaroxaban displayed higher risks of ischemic stroke compared to warfarin.

Interactions between antiepileptic drugs and direct oral anticoagulants for primary and secondary stroke prevention.

INTRODUCTION: Direct oral anticoagulants (DOAC) are the guideline-recommended therapy for prevention of stroke in atrial fibrillation (AF) and venous thromboembolism. Since approximately 10% of patients using antiepileptic drugs (AED) also receive DOAC, aim of this review is to summarize data about drug-drug interactions (DDI) of DOAC with AED by using data from PubMed until December 2023. AREAS COVERED: Of 49 AED, only 16 have been investigated regarding DDI with DOAC by case reports or observational studies. No increased risk for stroke was reported only for topiramate, zonisamide, pregabalin, and gabapentin, whereas for the remaining 12 AED conflicting results regarding the risk for stroke and bleeding were found. Further 16 AED have the potential for pharmacodynamic or pharmacokinetic DDI, but no data regarding DOAC are available. For the remaining 17 AED it is unknown if they have DDI with DOAC. EXPERT OPINION: Knowledge about pharmacokinetic and pharmacodynamic DDI of AED and DOAC is limited and frequently restricted to in vitro and in vivo findings. Since no data about DDI with DOAC are available for 67% of AED and an increasing number of patients have a combined medication of DOAC and AED, there is an urgent need for research on this topic.

Performance of direct oral anticoagulant (DOAC) testing by hemostasis laboratories: The Australasian/Asia-Pacific experience.

INTRODUCTION: Direct oral anticoagulants (DOACs) reflect anticoagulation agents given to treat or prevent thrombosis, having largely replaced vitamin K antagonists (VKAs) such as warfarin. DOACs are given in fixed daily doses and generally do not need monitoring. However, there may be a variety of reasons that justify measurement of plasma DOAC levels in individual patients. METHODS: We report updated findings for DOAC testing in our geographic region, using recent data from the RCPAQAP, an international external quality assessment (EQA) program, currently with some 40-60 participants in each of the different DOAC (rivaroxaban, apixaban, dabigatran) modules, to assess laboratory performance in this area. Data has been assessed for the past 5 years (2019-2023 inclusive), with 20 samples each per DOAC. RESULTS: Data shows a limited repertoire of assays in use, and mostly consistency in reported numerical values when assessing proficiency samples. Available assays mostly comprised reagents from four manufacturing suppliers. There was good consistency across what participants identified as 'DOAC detected', but some variability when participants attempted to grade DOAC levels as low vs moderate vs high. Inter-laboratory/method coefficient of variation (CVs) were generally <15% for each DOAC, when present at >100 ng/mL. CONCLUSION: We hope our findings, reflecting on mostly consistent reporting of DOAC levels and interpretation provides reassurance for clinicians requesting these measurements, and helps support their implementation in regions where there is a paucity of test availability.

The Management of a Geriatric Patient Using Dabigatran Therapy on Dentigerous Cyst with Oral Bleeding.

Jaw cysts represent a great matter of interest in oral and maxillofacial surgery. Jaw cyst surgery is a common intervention in oral surgery but, in the case of a multidisciplinary patient, the oral surgeon needs to meet with other specialists. A cyst is an epithelium-lined sac containing fluid and/or semisolid material due to epithelial cell proliferation, degeneration, and liquefaction; the hypertonic solution withdraws liquids from the surrounding tissues, while internal pressure exerts an equal strength on the cyst walls. Dentigerous cysts are the second most common odontogenic cysts after radicular cysts, and commonly few or no symptoms are reported. However, the most common diagnosis for dentigerous cyst is represented by eruption of the affected tooth or accidental diagnosis. Commonly, dentigerous cysts may be related to impacted third molars; in the case of impacted third molars and a dentigerous cyst, the tooth should be removed along with the cyst in the same intervention. Mandibular dentigerous cysts are common in children and adults, while dentigerous cysts are a rare neoformation in elderly patients. Treatment usually involves removal of the entire cyst and the associated unerupted tooth. This intervention may be more difficult if the cyst is large, the third molar is in contact with the mandibular nerve, and/or the patient has a medical history that may represent a relative or absolute contraindication. We present the case of a rare symptomatic manifestation of dentigerous cyst in an elderly patient in treatment with dabigatran therapy; for the treatment of dentigerous cysts in the elderly, we suggest a multidisciplinary approach with the use of the histological examination and a careful follow-up.

Unified Methodology for the Primary Preclinical In Vivo Screening of New Anticoagulant Pharmaceutical Agents from Hematophagous Organisms.

The development of novel anticoagulants requires a comprehensive investigational approach that is capable of characterizing different aspects of antithrombotic activity. The necessary experiments include both in vitro assays and studies on animal models. The required in vivo approaches include the assessment of pharmacokinetic and pharmacodynamic profiles and studies of hemorrhagic and antithrombotic effects. Comparison of anticoagulants with different mechanisms of action and administration types requires unification of the experiment scheme and its adaptation to existing laboratory conditions. The rodent thrombosis models in combination with the assessment of hemostasis parameters and hematological analysis are the classic methods for conducting preclinical studies. We report an approach for the comparative study of the activity of different anticoagulants in vivo, including the investigation of pharmacodynamics and the assessment of hemorrhagic effects (tail-cut bleeding model) and pathological thrombus formation (inferior vena cava stenosis model of venous thrombosis). The reproducibility and uniformity of our set of experiments were illustrated on unfractionated heparin and dabigatran etexilate (the most common pharmaceuticals in antithrombic therapy) as comparator drugs and an experimental drug variegin from the tick Amblyomma variegatum. Variegin is notorious since it is a potential analogue of bivalirudin (Angiomax, Novartis AG, Basel, Switzerland), which is now being actively introduced into antithrombotic therapy.