Ticlopidine induces embryonic development toxicity and hepatotoxicity in zebrafish by upregulating the oxidative stress signaling pathway.

Ticlopidine exerts its anti-platelet effects mainly by antagonizing platelet p2y12 receptors. Previously, a few studies have shown that ticlopidine can induce liver injury, but the exact mechanism of hepatotoxicity remains unclear. Oxidative stress, metabolic disorders, hepatocyte apoptosis, lipid peroxidation, and inflammatory responses can all lead to hepatic liver damage, which can cause hepatotoxicity. In this study, in order to deeply explore the potential molecular mechanisms of ticlopidine -induced hepatotoxicity, we used zebrafish as a model organism to comprehensively evaluate the hepatotoxicity of ticlopidine and its associated mechanism. Three days post-fertilization, zebrafish larvae were exposed to varying concentrations (1.5, 1.75 and 2 µg/mL) of ticlopidine for 72 h, in contrast, adult zebrafish were exposed exposure to 4 µg/mL of ticlopidine for 28 days. Ticlopidine-exposed zebrafish larvae showed changes in liver morphology, shortened body length, and delayed development of the swim bladder development. Liver tissues of ticlopidine-exposed zebrafish larvae and adults stained with Hematoxylin & Eosin revealed vacuolization and increased cellular interstitial spaces in liver tissues. Furthermore, using Oil Red O and periodic acid-Schiff staining methods and evaluating different metabolic enzymes of ticlopidine-exposed zebrafish larvae and adults suggested abnormal liver metabolism and liver injury in both ticlopidine-exposed zebrafish larvae and adults. Ticlopidine also significantly elevated inflammation and oxidative stress and reduced hepatocyte proliferation. During the rescue intervention using N-acetylcysteine, we observed significant improvement in ticlopidine-induced morphological changes in the liver, shortened body length, delayed swim bladder development, and proliferation of liver tissues showed significant improvement. In conclusion, ticlopidine might inhibit normal development and liver proliferation in zebrafish by upregulation of oxidative stress levels, thus leading to embryonic developmental toxicity and hepatotoxicity. In this study, we used zebrafish as a model organism to elucidate the developmental toxicity and hepatotoxicity induced by ticlopidine upregulation of oxidative stress signaling pathway in zebrafish, providing a theoretical basis for clinical application.

Synthesis and structure-activity relationships of ticlopidine derivatives and analogs as inhibitors of ectonucleotidase CD39.

Ticlopidine is an antithrombotic prodrug of the thienotetrahydropyridine family. For platelet inhibition it has to undergo oxidative ring-opening by cytochrome P450 enzymes. The resulting thiol reacts with a cysteine residue of the purinergic P2Y12 receptor on thrombocytes resulting in covalent receptor blockade. Ticlopidine in its intact, not-metabolized form was previously shown to inhibit ecto-nucleoside triphosphate diphosphohydrolase-1 (NTPDase1, also known as cluster of differentiation (CD) 39). CD39 catalyzes the extracellular hydrolysis of ATP via ADP to AMP, which is further hydrolyzed by ecto-5'-nucleotidase (CD73) to adenosine. CD39 inhibition has been proposed as a novel strategy to increase the extracellular concentration of antiproliferative ATP, while decreasing immunosuppressive and cancer-promoting adenosine levels. In the present study, we performed an extensive structure-activity relationship (SAR) analysis of ticlopidine derivatives and analogs as CD39 inhibitors followed by an in-depth characterization of selected compounds. Altogether 74 compounds were synthesized, 41 of which are new, not previously described in literature. Benzotetrahydropyridines, in which the metabolically labile thiophene is replaced by a benzene ring, were discovered as a new class of allosteric CD39 inhibitors.

The anti-platelet drug ticlopidine inhibits FapC fibrillation and biofilm production: Highlighting its antibiotic activity.

Multidrug resistance of bacteria and persistent infections related to biofilms, as well as the low availability of new antibacterial drugs, make it urgent to develop new antibiotics. Here, we evaluate the antibacterial and anti-biofilm properties of ticlopidine (TP), an anti-platelet aggregation drug, TP showed antibacterial activity against both gram-positive (MRSA) and gram-negative (E. coli, and P. aeruginosa) bacteria over a long treatment period. TP significantly reduced the survival of gram-negative bacteria in human blood though impact on gram-positives was more limited. TP may cause death in MRSA by inhibiting staphyloxanthin pigment synthesis, leading to oxidative stress, while scanning electron microscopy imaging indicate a loss of membrane integrity, damage, and consequent death due to lysis in gram-negative bacteria. TP showed good anti-biofilm activity against P. aeruginosa and MRSA, and a stronger biofilm degradation activity on P. aeruginosa compared to MRSA. Measuring fluorescence of the amyloid-reporter Thioflavin T (ThT) in biofilm implicated inhibition of amyloid formation as part of TP activity. This was confirmed by assays on the purified protein in P. aeruginosa, FapC, whose fibrillation kinetics was inhibited by TP. TP prolonged the lag phase of aggregation and reduced the subsequent growth rate and prolonging the lag phase to very long times provides ample opportunity to exert TP's antibacterial effect. We conclude that TP shows activity as an antibiotic against both gram-positive and gram-negative bacteria thanks to a broad range of activities, targeting bacterial metabolic processes, cellular structures and the biofilm matrix.

Repurposing the Antiplatelet Agent Ticlopidine to Counteract the Acute Phase of ER Stress Condition: An Opportunity for Fighting Coronavirus Infections and Cancer.

Different pathological conditions, including viral infections and cancer, can have a massive impact on the endoplasmic reticulum (ER), causing severe damage to the cell and exacerbating the disease. In particular, coronavirus infections, including SARS coronavirus-2 (SARS-CoV-2), responsible for COVID-19, cause ER stress as a consequence of the enormous amounts of viral glycoproteins synthesized, the perturbation of ER homeostasis and the modification of ER membranes. Therefore, ER has a central role in the viral life cycle, thus representing one of the Achilles' heels on which to focus therapeutic intervention. On the other hand, prolonged ER stress has been demonstrated to promote many pro-tumoral attributes in cancer cells, having a key role in tumor growth, metastasis and response to therapies. In this report, adopting a repurposing approach of approved drugs, we identified the antiplatelet agent ticlopidine as an interferent of the unfolded protein response (UPR) via sigma receptors (SRs) modulation. The promising results obtained suggest the potential use of ticlopidine to counteract ER stress induced by viral infections, such as COVID-19, and cancer.

Antiplatelet Use in Ischemic Stroke.

OBJECTIVE: A literature review of antiplatelet agents for primary and secondary stroke prevention, including mechanism of action, cost, and reasons for lack of benefit. DATA SOURCES: Articles were gathered from MEDLINE, Cochrane Reviews, and PubMed databases (1980-2021). Abstracts from scientific meetings were considered. Search terms included ischemic stroke, aspirin, clopidogrel, dipyridamole, ticagrelor, cilostazol, prasugrel, glycoprotein IIb/IIIa inhibitors. STUDY SELECTION AND DATA EXTRACTION: English-language original and review articles were evaluated. Guidelines from multiple countries were reviewed. Articles were evaluated independently by 2 authors. DATA SYNTHESIS: An abundance of evidence supports aspirin and clopidogrel use for secondary stroke prevention. In the acute phase (first 21 days postinitial stroke), these medications have higher efficacy for preventing further stroke when combined, but long-term combination therapy is associated with higher hemorrhage rates. Antiplatelet treatment failure is influenced by poor adherence and genetic polymorphisms. Antiplatelet agents such as cilostazol may provide extra benefit over clopidogrel and aspirin, in certain racial groups, but further research in more diverse ethnic populations is needed. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: This review presents the data available on the use of different antiplatelet agents poststroke. Dual therapy, recurrence after initiation of secondary preventative therapy, and areas for future research are discussed. CONCLUSIONS: Although good evidence exists for the use of certain antiplatelet agents postischemic stroke, there are considerable opportunities for future research to investigate personalized therapies. These include screening patients for platelet polymorphisms that confer antiplatelet resistance and for randomized trials including more racially diverse populations.

Ticlopidine induces cardiotoxicity in zebrafish embryos through AHR-mediated oxidative stress signaling pathway.

Ticlopidine has inhibitory effects on platelet aggregation via ADP (adenosine diphosphate), platelet release reaction and depolymerization. In clinical practice, it is commonly used to prevent heart, cerebrovascular and other thromboembolic diseases. However, ticlopidine has also been reported to have teratogenic effects on the heart, though its specific molecular mechanism remains unclear. In this study, zebrafish embryos were used as model organisms to examine the toxicity effect of ticlopidine. Zebrafish embryos exposed to 6, 7.5, and 9 mg/L ticlopidine solutions manifested several abnormalities, including body curvature, smaller eyes, slower absorption of the vitella sac, pericardial edema, slower heart rate, increased mortality, longer venous sinus - arterial ball (SV-BA) distance, and increased oxidative stress, which indicated developmental and cardiac toxicity. Abnormal expression of key genes related to heart development was observed, and the level of apoptotic gene expression was up-regulated. Further experiments revealed up-regulation of embryonic oxidative stress following ticlopidine exposure, leading to a decrease in cardiomyocyte proliferation. Conversely, the aromatic hydrocarbon receptor (AHR) inhibitor CH223191 protected embryos from the cardiotoxicity effect of ticlopidine, confirming further the role of up-regulated oxidative stress as the molecular mechanism of ticlopidine-induced cardiotoxicity in zebrafish. In conclusion, ticlopidine exposure leads to developmental and cardiotoxicity in zebrafish embryos. Therefore, further studies are warranted to ascertain such potential harms of ticlopidine in humans, which are vital in providing guidance in the safe use of drugs in clinical practice.

Highly productive and scalable approach to synthesize ticlopidine: A potent thienopyridine anti-platelet aggregation drug.

Ticlopidine (trade name Ticlid), an acidic thienopyridine derivative, is an effective, well-known and long-acting inhibitor of platelet aggregation. Because of its potent inhibitory activity for treating a variety of diseases, the development of efficient approaches for accessing ticlopidine represents an important endeavour. Therefore, in this research work, we developed a promising novel five-step synthetic approach for synthesizing ticlopidine. This method provides ticlopidine in 60% overall yield from readily available starting material viz. thiophene. In this methodology, all steps afforded excellent yields and are operationally simple and environmentally acceptable. This approach also offers various attractive advantages, for example, it's applicable for large-scale synthesis, has simple work-up procedures and short reaction times, and uses inexpensive and readily available reagents. Furthermore, 4,5,6,7-tetrahydrothieno[3,2-c]pyridine is a key precursor for the synthesis of numerous bioactive compounds such as prasugrel and clopidogrel. This protocol provides 4,5,6,7-tetrahydrothieno[3,2-c]pyridine in 62% overall yield via a 4-step synthetic approach.

Risk of bradyarrhythmia related to ticagrelor: A systematic review and meta-analysis.

CONTEXT: Ticagrelor was related to bradycardia in DISPERSE-II trial. This risk has been integrated into the European risk-management plan, and its use is warned in at-risk patients. Nevertheless, this risk was not systematically assessed nor measured. OBJECTIVES: To estimate the risk of bradyarrhythmia associated with ticagrelor. STUDY DESIGN: Systematic review and meta-analysis. DATA-SOURCE: MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, ISI web of Science, clinicaltrial.gov, clinicaltrialsregister.eu. STUDY SELECTION: Randomized controlled trials (RCTs) and observational studies in patients treated with ticagrelor or comparator(s). META-ANALYSIS: Risk of bias in each RCT was assessed using Cochrane tool. Relative Risks (RR) with 95 % confidence intervals (95 %CI) were calculated for each RCT, and pooled using fixed-effect or random-effects models, when appropriate. Subgroup and sensitivity analyses were performed. A potential publication bias was searched. RESULTS: Among 82 eligible studies, event data were missing for 56 studies, due to detected reporting bias (i.e. inability to confirm zero events). Fifteen RCTs were selected and the combined RR of bradyarrhythmia was 1.15 (95 %CI 1.05-1.26), and 1.29 (1.02-1.65) for severe bradyarrhythmia. The risk appeared to be dose dependent. Restricting the analysis only to RCTs performed in patients without previous bradyarrhythmia resulted in a non-increased risk. CONCLUSION: This meta-analysis confirmed the risk of bradyarrhythmia or severe bradyarrhythmia related to ticagrelor, and its use in patients without previous bradycardia was effective in preventing it. The evidence coming from this meta-analysis was low to moderate due to missing outcome in 2/3 of eligible studies. Waiting for access to these data, the use of ticagrelor in patients with risk factors of bradycardias should be avoided.

State of Art of Idiosyncratic Drug-Induced Neutropenia or Agranulocytosis, with a Focus on Biotherapies.

INTRODUCTION: Idiosyncratic drug-induced neutropenia and agranulocytosis is seldom discussed in the literature, especially for new drugs such as biotherapies outside the context of oncology. In the present paper, we report and discuss the clinical data and management of this relatively rare disorder, with a focus on biotherapies used in autoimmune and auto-inflammatory diseases. MATERIALS AND METHODS: A review of the literature was carried out using the PubMed database of the US National Library of Medicine. We searched for articles published between January 2010 and May 2019 using the following key words or associations: "drug-induced neutropenia", "drug-induced agranulocytosis", and "idiosyncratic agranulocytosis". We included specific searches on several biotherapies used outside the context of oncology, including: tumor necrosis factor (TNF)-alpha inhibitors, anti-CD20 agents, anti-C52 agents, interleukin (IL) 6 inhibitors, IL 1 inhibitors, and B-cell activating factor inhibitor. RESULTS: Idiosyncratic neutropenia remains a potentially serious adverse event due to the frequency of severe sepsis with severe deep tissue infections (e.g., pneumonia), septicemia, and septic shock in approximately two-thirds of all hospitalized patients with grade 3 or 4 neutropenia (neutrophil count (NC) ≤ 0.5 × 109/L and ≤ 0.1 × 109/L, respectively). Over the last 20 years, several drugs have been strongly associated with the occurrence of idiosyncratic neutropenia, including antithyroid drugs, ticlopidine, clozapine, sulfasalazine, antibiotics such as trimethoprim-sulfamethoxazole, and deferiprone. Transient grade 1-2 neutropenia (absolute blood NC between 1.5 and 0.5 × 109/L) related to biotherapy is relatively common with these drugs. An approximate 10% prevalence of such neutropenia has been reported with several of these biotherapies (e.g., TNF-alpha inhibitors, IL6 inhibitors, and anti-CD52 agents). Grade 3-4 neutropenia or agranulocytosis and clinical manifestations related to sepsis are less common, with only a few case reports to date for most biotherapies. Special mention should be made of late onset and potentially severe neutropenia, especially following anti-CD52 agent therapy. During drug therapy, several prognostic factors have been identified that may be helpful when identifying 'susceptible' patients. Older age (>65 years), septicemia or shock, renal failure, and a neutrophil count ≤0.1 × 109/L have been identified as poor prognostic factors. Idiosyncratic neutropenia should be managed depending on clinical severity, with permanent/transient discontinuation or a lower dose of the drug, switching from one drug to another of the same or another class, broad-spectrum antibiotics in cases of sepsis, and hematopoietic growth factors (particularly G-CSF). CONCLUSION: Significant progress has been made in recent years in the field of idiosyncratic drug-induced neutropenia, leading to an improvement in their prognosis (currently, mortality rate between 5 and 10%). Clinicians must continue their efforts to improve their knowledge of these adverse events with new drugs as biotherapies.

Efficacy of Antiplatelet Agent Usage for Primary and Secondary Prevention in Dialysis Patients: a Nationwide Data Survey and Propensity Analysis.

BACKGROUND: Although cardiovascular (CV) disease is the leading cause of mortality and morbidity in dialysis patients, there is little evidence to guide the use of antiplatelet agents in dialysis patients. METHOD: A nationwide database (Registry for Catastrophic Illnesses) for Taiwan, which has data from nearly all patients who received dialysis therapy from 1995 to 2008, was used. This is a population-based cohort study with time to event analyses to estimate the relation between antiplatelet agent use and outcomes. Hazard ratios were calculated to evaluate the effect of antiplatelet agent use on the risk of major CV events and mortality. Baseline characteristics were matched by propensity score (PS). RESULTS: A total of 71,835 were included, and 10,595 (14.7%) patients received an anti-platelet agent. The median value of follow-up days was 61.6 months. After PS-based matching, 9598 patients who used an antiplatelet agent and 23,794 non-users were included in the analysis. After PS matching, there was no difference between patients using an antiplatelet agent or not in CV events (p = 0.672) and total mortality (p = 0.529). A subgroup analysis of different usage periods of antiplatelet agents indicated that CV events and total mortality were similar in those who used antiplatelet agents for short or long durations. In subgroup analysis, there was also no difference between patients with a different modality of dialysis (hemodialysis or peritoneal dialysis), different antiplatelet agents (aspirin, clopidogrel, and/or ticlopidine) or patients with/without previous cardiovascular disease in CV events and total mortality. CONCLUSIONS: Antiplatelet agent usage does not reduce CV events and total mortality in dialysis patients.

Comparison of Clopidogrel and Ticlopidine/Ginkgo Biloba in Patients With Clopidogrel Resistance and Carotid Stenting.

Background and Purpose: Patients undergoing carotid artery stenting (CAS) who show low responsiveness to clopidogrel may have a higher risk of peri-procedural embolic events. This study aimed to compare the effectiveness and safety of clopidogrel and ticlopidine plus Ginkgo biloba in clopidogrel-resistant patients undergoing CAS. Methods: In this multi-center, randomized, controlled trial, we used platelet reactivity test to select patients undergoing CAS who showed clopidogrel resistance, and compared treatments using clopidogrel and ticlopidine plus ginkgo. The primary outcome was the incidence of new ischemic lesion in the ipsilateral hemisphere of CAS. Detection of microembolic signal on transcranial Doppler was the secondary outcome. The clinical outcomes were also monitored. Results: This trial was discontinued after 42 patients were randomized after preplanned interim sample size re-estimation indicated an impractical sample size. The primary endpoint occurred in 12/22 patients (54.5%) in the clopidogrel group and 13/20 patients (65.0%) in the ticlopidine-ginkgo group (P = 0.610). No significant differences in the presence of microembolic signal (15.0 vs. 11.8%, P = 0.580), clinical outcomes (ischemic stroke or transient ischemic attack, 0.0 vs. 5.5%; acute myocardial infarction 0.0 vs. 0.0%; all-cause death, 4.5 vs. 0.0%), or incidence of adverse events were found in the two groups. In terms of resistance to clopidogrel, treatment with ticlopidine-ginkgo significantly increased the P2Y12 Reaction Units (difference, 0.0 [-0.3-3.0] vs. 21.0 [6.0-35.0], P < 0.001). Conclusions: In patients who showed clopidogrel resistance, ticlopidine-ginkgo treatment was safe and increased P2Y12 Reaction Units; however, compared to clopidogrel, it failed to improve surrogate and clinical endpoints in patients undergoing CAS. This multimodal biomarker-based clinical trial is feasible in neurointerventional research. Clinical Trial Registration: http://www.clinicaltrials.gov. Unique identifier: NCT02133989.

Elucidating the interaction of ticlopidine with serum albumin and its role in bilirubin displacement in vitro.

Ticlopidine is an anti-platelet drug that functions as a P2Y12 receptor antagonist. The present study provides a detailed characterization of interaction of ticlopidine with a model transport protein, bovine serum albumin (BSA) as well as an assessment of its bilirubin displacing ability using a multi-spectroscopic approach in combination with isothermal titration calorimetry. The value of binding constant determined using ITC studies was found to be 3.03 × 103 M-1 with a binding stoichiometry of approximately 1:1. Competitive site marker experiments indicate that ticlopidine binds to Sudlow site I, located in subdomain IIA of BSA. In addition, Circular dichroism and 3D fluorescence spectroscopy indicated structural and conformational changes in BSA on interaction with ticlopidine. Thermodynamic parameters suggested that the reaction was spontaneous, exothermic, entropically driven, and involved hydrophobic interactions. These results were well supported by those obtained through molecular docking studies. Additionally, the effect of ticlopidine on bilirubin and albumin interaction was evaluated using the peroxidase method as well as through fluorescence spectroscopy. Ticlopidine was found to displace bilirubin from serum albumin. Moreover, the binding constant of bilirubin-serum albumin interaction also decreased in presence of ticlopidine. The results indicated that ticlopidine is a competitive displacer of bilirubin in vitro and may contribute to the incidences hyperbilirubinemia associated with the usage of this drug.

Comparing Allergist and Cardiologist Considerations for the Optimal Management of Thienopyridines Hypersensitivity.

BACKGROUND AND OBJECTIVE: The thienopyridine family includes ticlopidine, clopidogrel and prasugrel which are antiplatelet drugs largely used, mainly associated to aspirin, for treatment of acute coronary syndromes and after percutaneous coronary interventions, to avoid thrombosis. In some patients, thienpyridines may cause hypersensitivity reactions which jeopardize the optimal therapeutic and preventive approach to vascular diseases. The management of thienopyridine hypersensitivity seems to be best done as an interdisciplinary collaboration between the allergist and cardiologist. METHOD: The present study investigates the management of thienopyridines hypersensitivity on the basis of published case reports and studies, comparing the pro and contro of pharmacological treatments, different desensitization protocols to thienopyridines and substitution of antiplatelet agents eaches others, according to the point of view of cardiologist and allergist. For the cardiologist, the important issues are the necessity of continuing therapy, the desired duration of therapy based on the clinical indication of the individual patient and appropriateness of using one of the alternative P2Y12 inhibitors. For the allergist, the important issues are weighing the risk and benefits of the various therapeutic options: treating "through" desensitization, or switching to an alternative agent. RESULTS AND CONCLUSION: All the data seem to suggest that only working together, a cardio-allergy team of specialists may evaluate and offer the best approach to clinical decision-making for the individual patient.

Molecular spectroscopic and thermodynamic studies on the interaction of anti-platelet drug ticlopidine with calf thymus DNA.

Ticlopidine is an anti-platelet drug which belongs to the thienopyridine structural family and exerts its effect by functioning as an ADP receptor inhibitor. Ticlopidine inhibits the expression of TarO gene in S. aureus and may provide protection against MRSA. Groove binding agents are known to disrupt the transcription factor DNA complex and consequently inhibit gene expression. Understanding the mechanism of interaction of ticlopidine with DNA can prove useful in the development of a rational drug designing system. At present, there is no such study on the interaction of anti-platelet drugs with nucleic acids. A series of biophysical experiments were performed to ascertain the binding mode between ticlopidine and calf thymus DNA. UV-visible and fluorescence spectroscopic experiments confirmed the formation of a complex between ticlopidine and calf thymus DNA. Moreover, the values of binding constant were found to be in the range of 103M-1, which is indicative of groove binding between ticlopidine and calf thymus DNA. These results were further confirmed by studying the effect of denaturation on double stranded DNA, iodide quenching, viscometric studies, thermal melting profile as well as CD spectral analysis. The thermodynamic profile of the interaction was also determined using isothermal titration calorimetric studies. The reaction was found to be endothermic and the parameters obtained were found to be consistent with those of known groove binders. In silico molecular docking studies further corroborated well with the experimental results.

Post Hoc Analyses of Randomized Clinical Trial for the Effect of Clopidogrel Added to Aspirin on Kidney Function.

BACKGROUND AND OBJECTIVES: Despite the high burden of CKD, few specific therapies are available that can halt disease progression. In animal models, clopidogrel has emerged as a potential therapy to preserve kidney function. The effect of clopidogrel on kidney function in humans has not been established. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The Secondary Prevention of Small Subcortical Strokes Study randomized participants with prior lacunar stroke to treatment with aspirin or aspirin plus clopidogrel. We compared annual eGFR decline and incidence of rapid eGFR decline (≥30% from baseline) using generalized estimating equations and interval-censored proportional hazards regression, respectively. We also stratified our analyses by baseline eGFR, systolic BP target, and time after randomization. RESULTS: At randomization, median age was 62 (interquartile range, 55-71) years old; 36% had a history of diabetes, 90% had hypertension, and the median eGFR was 81 (interquartile range, 65-94) ml/min per 1 m2. Persons receiving aspirin plus clopidogrel had an average annual change in kidney function of -1.39 (95% confidence interval, -1.15 to -1.62) ml/min per 1.73 m2 per year compared with -1.52 (95% confidence interval, -1.30 to -1.74) ml/min per 1.73 m2 per year among persons receiving aspirin only (P=0.42). Rapid kidney function decline occurred in 21% of participants receiving clopidogrel plus aspirin compared with 22% of participants receiving aspirin plus placebo (hazard ratio, 0.94; 95% confidence interval, 0.79 to 1.10; P=0.42). Findings did not vary by baseline eGFR, time after randomization, or systolic BP target (all P values for interaction were >0.3). CONCLUSIONS: We found no effect of clopidogrel added to aspirin compared with aspirin alone on kidney function decline among persons with prior lacunar stroke.

Antithrombotic Activity of DAB-15, a Novel Diazepinobenzimidazole Compound.

Antithrombotic activity of a new orally administered antiplatelet compound DAB-15 was compared to that of acetylsalicylic acid, ticlopidine, and clopidogrel in the experimental model of arterial thrombosis in rats caused by surface application of 50% ferric chloride (III) on the carotid artery. Compound DAB-15 exerted a dose-dependent antithrombotic effect and was superior to acetylsalicylic acid, ticlopidine and clopidogrel by 5, 7, and 4.9 times, respectively (by ED50). This necessitates studying of the action mechanism of this antiplatelet compound with consideration of its influence on different stages of the pathogenesis of platelet aggregation.

Inhibidores del receptor plaquetario P2Y12. Parte 1 de 2: escenario de acción, farmacología, aplicación clínica y limitaciones de su uso / Platelet P2Y12 receptor inhibitors. Part 1 of 2: Scenario of action, pharmacology, clinical application, and limitations of its use

Resumen: las enfermedades cardiovasculares, incluidas las afecciones del corazón, del cerebro y de los vasos sanguíneos en general, representan la primera causa de muerte a nivel mundial, con diecisiete millones y medio de muertes cada año. La prevención primaria y secundaria de las enfermedades aterotrombóticas, como el infarto agudo de miocardio, el accidente cerebrovascular y las enfermedades trombóticas, además de las medidas generales para el control de los factores de riesgo tales como la obesidad, el sedentarismo, el tabaquismo, la hipertensión arterial y la diabetes, se han centrado en el control de la agregación plaquetaria. El antiagregante plaquetario por excelencia o universal, sobre todo en la prevención primaria, es la aspirina y la terapia dual con la combinación de aspirina y un inhibidor del receptor plaquetario P2Y12, principalmente el clopidogrel, es usada en la prevención secundaria y en los casos de resistencia a la aspirina. En el momento, se dispone para uso clínico de seis inhibidores del receptor plaquetario P2Y12: la ticlopidina, el clopidogrel, el prasugrel, el ticagrelor, el cangrelor y el elinogrel. En este primer módulo, de dos que serán presentados, se abordará el uso de los inhibidores del receptor plaquetario P2Y12 en la práctica del día a día en la prevención primaria y secundaria de las enfermedades aterotrombóticas, enfocado en el análisis del papel de las plaquetas en la fisiopatología de la enfermedad aterotrombótica y la descripción de los seis inhibidores del receptor plaquetario P2Y12 disponibles ahora y en el futuro. En un segundo módulo se hará una aproximación al concepto de la resistencia a los inhibidores del receptor plaquetario P2Y12, su diagnóstico desde el punto de vista del laboratorio y las diferentes alternativas de manejo cuando se presenta resistencia a uno de estos medicamentos. (AU)

Abstract: Cardiovascular diseases, including in general heart diseases, brain, and blood vessels are the leading cause of death worldwide with 17.000.000 of deaths each year. Primary and secondary prevention of atherothrombotic diseases, as acute myocardial infarction, stroke, and thrombotic disorders, besides to the general measures for risk factors control such as obesity, sedentary lifestyle, smoke, high blood pressure, and diabetes, have focused on platelet aggregation control. The antiplatelet agent par excellence or universal, especially in primary prevention, is aspirin, and dual therapy with the combination of aspirin and a platelet receptor inhibitor P2Y12, with clopidogrel as the most used, for secondary prevention and in cases of aspirin resistance. Currently, six P2Y12 platelet receptor inhibitors are available for clinical use: ticlopidine, clopidogrel, prasugrel, ticagrelor, cangrelor, and elinogrel. In this first of two modules, the use of P2Y12 receptor inhibitors in daily practice in the primary and secondary prevention of atherothrombotic diseases will be addressed focused on the analysis of the platelets role in atherothrombotic disease pathophysiology and description of the six P2Y12 platelet receptor inhibitors available now and in the future. In a second module, we will approach the concept of resistance to platelet P2Y12 receptor inhibitors, its diagnosis from the laboratory point of view and the different management alternatives when resistance to one of these drugs is present. (AU)

Influence of aspirin/clopidogrel treatment on platelet aggregation rate and analysis of drug resistance in the patients with coronary heart disease / 中国医师杂志

Objective To investigate the influence of aspirin and/or clopidogrel treatment on platelet aggregation rate in coronary heart disease (CHD) patients,and discuss the factors related to anti-platelet drug resistance.Methods A total of 160 patients with CHD and received aspirin and/or clopidogrel treatment were enrolled in the Second Xiangya Hospital,Central South University,and were divided into stable coronary heart disease (SCHD) group (n =90) and acute coronary syndrome (ACS) group (n =70).Meanwhile,non-coronary heart disease (NCHD) patients who did not receive anti-platelet drug treatment were enrolled as controls (n =50).Clinical data of the subjects were recorded.The maximum platelet aggregation rate induced by arachidonic acid (MAR-AA) and adenosine diphosphate (MAR-ADP) were evaluated with sequential platelet counting method.The factors related to drug resistance were analyzed with Logistic regression analysis.Results Compared to NCHD group,there were lower MAR-AA and MAR-ADP in two groups of CHD (all P ＜ 0.05).In ACS patients,MAR-AA and MAR-ADP are significantly lower (P ＜0.05) in patients who receive the aspirin and clopidogrel.The rate of anti-platelet drug resistance in ACS group was significantly higher than that in SCHD group (20.0％ vs 10.0％,P ＜ 0.05).Multivariate logistic regression analysis showed that low HDL-C (＜ 1.0 mmol/L) was an independent risk factor related to the anti-platelet drug resistance (OR =4.36,95 ％ CI:1.36-14.02,P =0.025).Conclusions The antiplatelet treatment with aspirin and/or clopidogrel can significantly reduce the platelet reactivity in CHD patients,but some patients still present anti-platelet drug resistance.The combination of aspirin and clopidogrel is better.The rate of drug resistance in ACS patients is high.Low HDL-C might be associated with anti-platelet drug resistance.

Influence of aspirin/clopidogrel treatment on platelet aggregation rate and analysis of drug resistance in the patients with coronary heart disease / 中国医师杂志

Objective To investigate the influence of aspirin and/or clopidogrel treatment on platelet aggregation rate in coronary heart disease (CHD) patients,and discuss the factors related to anti-platelet drug resistance.Methods A total of 160 patients with CHD and received aspirin and/or clopidogrel treatment were enrolled in the Second Xiangya Hospital,Central South University,and were divided into stable coronary heart disease (SCHD) group (n =90) and acute coronary syndrome (ACS) group (n =70).Meanwhile,non-coronary heart disease (NCHD) patients who did not receive anti-platelet drug treatment were enrolled as controls (n =50).Clinical data of the subjects were recorded.The maximum platelet aggregation rate induced by arachidonic acid (MAR-AA) and adenosine diphosphate (MAR-ADP) were evaluated with sequential platelet counting method.The factors related to drug resistance were analyzed with Logistic regression analysis.Results Compared to NCHD group,there were lower MAR-AA and MAR-ADP in two groups of CHD (all P ＜ 0.05).In ACS patients,MAR-AA and MAR-ADP are significantly lower (P ＜0.05) in patients who receive the aspirin and clopidogrel.The rate of anti-platelet drug resistance in ACS group was significantly higher than that in SCHD group (20.0％ vs 10.0％,P ＜ 0.05).Multivariate logistic regression analysis showed that low HDL-C (＜ 1.0 mmol/L) was an independent risk factor related to the anti-platelet drug resistance (OR =4.36,95 ％ CI:1.36-14.02,P =0.025).Conclusions The antiplatelet treatment with aspirin and/or clopidogrel can significantly reduce the platelet reactivity in CHD patients,but some patients still present anti-platelet drug resistance.The combination of aspirin and clopidogrel is better.The rate of drug resistance in ACS patients is high.Low HDL-C might be associated with anti-platelet drug resistance.