Triflusal

Impact of prior use of antiplatelets on COVID-19 susceptibility, progression, and severity: a population-based study

INTRODUCTION AND OBJECTIVES

Hypercoagulability and thromboembolism are processes that arise from severe acute respiratory syndrome coronavirus 2 infection and are responsible for a high degree of coronavirus disease 2019 (COVID-19)-related morbidity and mortality. This study sought to assess the effect of antiplatelet drugs on COVID-19 severity (risk of hospitalization and mortality), susceptibility to severe acute respiratory syndrome coronavirus 2 infection, and progression to severe COVID-19.

METHODS

We conducted a population-based case-control study in a northwestern region of Spain in 2020. The study involved 3060 participants with a positive polymerase chain reaction test who were hospitalized, 26 757 participants with a positive polymerase chain reaction test who were not hospitalized, and 56 785 healthy controls.

RESULTS

Triflusal seemed to be associated with a significant increase in risk of hospitalization (aOR, 1.97; 95%CI, 1.27-3.04) and susceptibility to infection (OR, 1.45; 95%CI, 1.07-1.96). It also appeared to lead to a nonsignificant increase in the risk of mortality (OR, 2.23; 95%CI, 0.89-5.55) and/or progression to more severe disease stages (OR, 1.42; 95%CI, 0.8-2.51). Aspirin seemed to be associated with a statistically significant decrease in susceptibility to severe acute respiratory syndrome coronavirus 2 infection (OR, 0.92; 95%CI, 0.86-0.98).

CONCLUSIONS

Triflusal use appears to increase the risk of susceptibility to COVID-19 infection and an even higher risk of hospitalization, whereas the other antiplatelets could be associated with a reduction in the risk of the various outcomes or have no effect on risk. These findings could support reconsideration of triflusal prescription in COVID-19 pandemic situations.

Antiplatelet drugs: Potential therapeutic options for the management of neurodegenerative diseases

The blood platelet plays an important role but often remains under-recognized in several vascular complications and associated diseases. Surprisingly, platelet hyperactivity and hyperaggregability have often been considered the critical risk factors for developing vascular dysfunctions in several neurodegenerative diseases (NDDs) like Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. In addition, platelet structural and functional impairments promote prothrombotic and proinflammatory environment that can aggravate the progression of several NDDs. These findings provide the rationale for using antiplatelet agents not only to prevent morbidity but also to reduce mortality caused by NDDs. Therefore, we thoroughly review the evidence supporting the potential pleiotropic effects of several novel classes of synthetic antiplatelet drugs, that is, cyclooxygenase inhibitors, adenosine diphosphate receptor antagonists, protease-activated receptor blockers, and glycoprotein IIb/IIIa receptor inhibitors in NDDs. Apart from this, the review also emphasizes the recent developments of selected natural antiplatelet phytochemicals belonging to key classes of plant-based bioactive compounds, including polyphenols, alkaloids, terpenoids, and flavonoids as potential therapeutic candidates in NDDs. We believe that the broad analysis of contemporary strategies and specific approaches for plausible therapeutic treatment for NDDs presented in this review could be helpful for further successful research in this area.

Semi-Mechanistic Modeling of HY-021068 Based on Irreversible Inhibition of Thromboxane Synthetase

Background: HY-021068 [4-(2-(1H-imidazol-1-yl) ethoxy)-3-methoxybenzoate], developed by Hefei Industrial Pharmaceutical Institute Co., Ltd. (Anhui, China), is a potential thromboxane synthetase inhibitor under development as an anti-platelet agent for the treatment of stroke. A semi-mechanistic pharmacokinetic/pharmacodynamic (PK/PD) model was developed to characterize the PK of HY-021068 and its platelet aggregation inhibitory effect in beagle dogs. Method: Beagle dogs received single oral administration of 2.5 mg/kg HY-021068 or consecutively oral administration of 5 mg/kg HY-021068 once daily for 7 days. The plasma concentration of HY-021068 and the platelet aggregation rate (PAR) were determined by liquid chromatography tandem-mass spectrometry (LC-MS/MS) assay and a photometric method, respectively. The PK/PD data was sequentially fitted by Phoenix NLME. The PK/PD parameters of HY-021068 in beagle dogs were estimated by 2.5 and 5 mg/kg dosing on the 1st day, and then used to simulate the PAR of HY-021068 on the 7th day after 5 mg/kg dosing daily. Result: A one-compartment model with saturable Michaelis-Menten elimination was best fitted to the PK of HY-021068. A mechanistic PD model based on irreversible inhibition of thromboxane synthetase was constructed to describe the relationship between plasma concentration of HY-021068 and PAR. Diagnostic plots showed no obvious bias. Visual predictive check confirmed the stability and reliability of the model. Most of PK/PD observed data on the 7th day after 5 mg/kg dosing fell in the 90% prediction interval. Conclusion: We established a semi-mechanistic PK/PD model for characterizing the PK of HY-021068 and its anti-platelet effect in beagle dogs. The model can be used to predict the concentration and PAR under different dosage regimen of HY-021068, and might be served as a reference for dose design in the future clinical studies.

Drug repositioning and repurposing for Alzheimer disease

Drug repositioning and repurposing can enhance traditional drug development efforts and could accelerate the identification of new treatments for individuals with Alzheimer disease (AD) dementia and mild cognitive impairment. Transcriptional profiling offers a new and highly efficient approach to the identification of novel candidates for repositioning and repurposing. In the future, novel AD transcriptional signatures from cells isolated at early stages of disease, or from human neurons or microglia that carry mutations that increase the risk of AD, might be used as probes to identify additional candidate drugs. Phase II trials assessing repurposed agents must consider the best target population for a specific candidate therapy as well as the mechanism of action of the treatment. In this Review, we highlight promising compounds to prioritize for clinical trials in individuals with AD, and discuss the value of Delphi consensus methodology and evidence-based reviews to inform this prioritization process. We also describe emerging work, focusing on the potential value of transcript signatures as a cost-effective approach to the identification of novel candidates for repositioning.

2-Hydroxy-4-Methylbenzoic Anhydride Inhibits Neuroinflammation in Cellular and Experimental Animal Models of Parkinson's Disease

Microglia-mediated neuroinflammation is one of the key mechanisms involved in acute brain injury and chronic neurodegeneration. This study investigated the inhibitory effects of 2-hydroxy-4-methylbenzoic anhydride (HMA), a novel synthetic derivative of HTB (3-hydroxy-4-trifluoromethylbenzoic acid) on neuroinflammation and underlying mechanisms in activated microglia in vitro and an in vivo mouse model of Parkinson’s disease (PD). In vitro studies revealed that HMA significantly inhibited lipopolysaccharide (LPS)-stimulated excessive release of nitric oxide (NO) in a concentration dependent manner. In addition, HMA significantly suppressed both inducible NO synthase and cyclooxygenase-2 (COX-2) at the mRNA and protein levels in LPS-stimulated BV-2 microglia cells. Moreover, HMA significantly inhibited the proinflammatory cytokines such as interleukin (IL)-1beta, IL-6, and tumor necrosis factor-alpha in LPS-stimulated BV-2 microglial cells. Furthermore, mechanistic studies ensured that the potent anti-neuroinflammatory effects of HMA (0.1, 1.0, and 10 μM) were mediated by phosphorylation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) in LPS-stimulated BV-2 cells. In vivo evaluations revealed that intraperitoneal administration of potent neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 20 mg/kg, four times a 1 day) in mice resulted in activation of microglia in the brain in association with severe behavioral deficits as assessed using a pole test. However, prevention of microglial activation and attenuation of Parkinson’s disease (PD)-like behavioral changes was obtained by oral administration of HMA (30 mg/kg) for 14 days. Considering the overall results, our study showed that HMA exhibited strong anti-neuroinflammatory effects at lower concentrations than its parent compound. Further work is warranted in other animal and genetic models of PD for evaluating the efficacy of HMA to develop a potential therapeutic agent in the treatment of microglia-mediated neuroinflammatory disorders, including PD.

Comparison of Triflusal with Aspirin in the Secondary Prevention of Atherothrombotic Events; Α Randomised Clinical Trial

BACKGROUND

Triflusal has demonstrated an efficacy similar to aspirin in the prevention of vascular events in patients with acute myocardial infarction (ΜΙ) and ischaemic stroke but with less bleeding events.

OBJECTIVE

We performed a randomised, multicentre, phase 4 clinical trial to compare the clinical efficacy and safety of triflusal versus aspirin, administered for 12 months in patients eligible to receive a cyclooxygenase-1 (COX-1) inhibitor.

METHODS

Patients with stable coronary artery disease or with a history of non-cardioembolic ischaemic stroke were randomly assigned to receive either triflusal 300 mg twice or 600 mg once daily or aspirin 100 mg once daily for 12 months. The primary efficacy endpoint was the composite of: (a) ΜΙ, (b) stroke (ischaemic or haemorrhagic), or, (c) death from vascular causes for the entire follow-up period. The primary safety endpoints were the rate of bleeding events as defined by Bleeding Academic Research Consortium (BARC) criteria.

RESULTS

At 12-month follow-up, an equivalent result was revealed between the triflusal (n=559) and aspirin (n=560) in primary efficacy endpoint. Specifically, the combined efficacy outcome rate (i.e. MI, stroke or death from vascular causes) difference was equal to -1.3% (95% confidence interval -1.1 to 3.5) and lied within the a-priori defined equivalence interval (p<0.001). Regarding the primary safety endpoints, patients on triflusal treatment were 50% less likely to develop bleeding events according to the BARC criteria, and especially any clinically overt sign of haemorrhage that requires diagnostic studies, hospitalisation or special treatment (BARC type 2).

CONCLUSION

The efficacy of triflusal in the secondary prevention of vascular events is similar to aspirin when administered for 12 months. Importantly, triflusal significantly reduced the incidence of ΜΙ and showed a better safety profile compared with aspirin. (ASpirin versus Triflusal for Event Reduction In Atherothrombosis Secondary prevention, ASTERIAS trial; Clinical Trials.gov Identifier: NCT02616497).

New approaches to inhibiting platelets and coagulation

Ischemic heart disease and stroke are major causes of death and morbidity worldwide. Coronary and cerebrovascular events are a consequence of thrombus formation caused by atherosclerotic plaque rupture or embolism, both of which result from platelet activation and aggregation and thrombin-mediated fibrin generation via the coagulation cascade. Current and emerging antiplatelet and anticoagulant agents are evolving rapidly. The use of aspirin for primary prevention continues to be controversial, as are the doses appropriate for secondary prevention. Development of new oral and intravenous adenosine diphosphate P2Y12 inhibitors and novel antiplatelet agents continues to transform the landscape of antiplatelet therapy. Oral anticoagulation has advanced with the use of direct thrombin and factor Xa inhibitors that do not require therapeutic monitoring. In this review, we discuss the pharmacology and growing clinical evidence for traditional and new antiplatelet and anticoagulant therapies.

Effect of Triflusal on Primary Vascular Dysregulation Compared with Aspirin: A Double-Blind, Randomized, Crossover Trial

PURPOSE

Primary vascular dysregulation (PVD) is a condition in which the response to cold temperature or external stimuli is abnormal. We investigated whether triflusal use results in amelioration of PVD symptoms and improvement of several related parameters compared with aspirin.

MATERIALS AND METHODS

Eighty-eight PVD patients (54% female, 56±8 years) were randomly selected to receive either triflusal (300 mg, b.i.d.) or aspirin (150 mg, b.i.d.) for a period of 6 weeks followed by crossover. PVD was defined as both red-blood-cell standstill in video-assisted microscopic capillaroscopy during cold stimulation using carbon dioxide gas and a score of more than 7 points in a validated questionnaire. Efficacy of treatment was assessed by 1) cold intolerance symptom severity (CISS) score, 2) finger Doppler indices, and 3) indocyanine green perfusion imaging.

RESULTS

The use of triflusal resulted in a greater improvement in CISS score (44.5±18.4 vs. 51.9±16.2; p<0.001) and in mean radial peak systolic velocity (69.8±17.2 vs. 66.1±16.4; p=0.011) compared to aspirin. Furthermore, significant differences were also observed in perfusion rates on indocyanine green perfusion imaging between triflusal and aspirin (45.6±25.8 vs. 51.6±26.9; p=0.020).

CONCLUSION

Triflusal was more effective and demonstrated a more consistent impact on the improvement of symptoms and blood flow in patients with PVD than aspirin.

Population pharmacokinetic and pharmacodynamic modeling of transformed binary effect data of triflusal in healthy Korean male volunteers: a randomized, open-label, multiple dose, crossover study

Background

Triflusal is a drug that inhibits platelet aggregation. In this study we investigated the dose-exposure-response relationship of a triflusal formulation by population pharmacokinetic (PK) and pharmacodynamic (PD) modeling of its main active metabolite, hydroxy-4-(trifluoromethyl) benzoic acid (HTB).

Methods

This study was a randomized, open-label, multiple-dose, two-period, two-treatment, comparative crossover design. All volunteers received a single oral loading dose of 900 mg of triflusal on Day 1, followed by a dose of 600 mg/day from Day 2 to 9. Using data from 34 healthy volunteers, 476 HTB plasma concentration data points and 340 platelet aggregation data points were used to construct PK and PD models respectively using NONMEM (version 6.2). As the PD endpoint was qualitative, we implemented binary analysis of ‘inhibition’ and ‘non-inhibition’ rather than using the actual value of the test. The final PK-PD model was evaluated using a visual predictive check (VPC) and bootstrap.

Results

The time-concentration profile of HTB over the entire dosing period was described by a one-compartment model with a first-order formation rate constant for HTB. Weight was selected as a covariate for clearance and volume of triflusal, respectively. The structure and the population estimates for triflusal PK were as follows: oral clearance (CL/F) = 0.2 · (weight/71.65)^0.845 L/h, oral volume of distribution (V/F) = 8.3 · (weight/71.65) L, and k_f = 0.341 h^-1. A sigmoid relationship between triflusal concentration and the probability of significant inhibition with shape factor was chosen as the final PD model. No time delay between concentration and response was identified. The final structure between predicted concentration and the probability of inhibition of platelet aggregation (IPA) relationship was as follows: Probability of . Thus, we concluded this relationship is more like quantal concentration-response relationship. The current dosing regimen was considered to be efficacious based on the EC₅₀ estimate of 84.9 μg/mL obtained in this study.

Conclusions

A PK and binary probability PD model of triflusal was successfully developed for Korean healthy volunteers. The model may be used to further prediction inhibition of platelet aggregation by triflusal.

Trial registration

Clinical Research Information Service (CRIS), KCT0001299 (Registered December 5, 2014)

Effect of premedication method and drug resistance of antiplatelet agent on periprocedural thromboembolic events during coil embolization of an unruptured intracranial aneurysm

Objective

A retrospective review of premedication method and drug resistance of aspirin and clopidogrel in association with thromboembolic events during and after coil embolization of an unruptured intracranial aneurysm was conducted.

Methods

Our premedication policy for coil embolization of an unruptured intracranial aneurysm has changed from administration of the loading dose before the procedure (i.e. loading group) to repeated administration of the maintenance dose for several days (i.e. preparation group). The loading group (27 patients with 29 aneurysms) and the preparation group (30 patients with 35 aneurysms) were compared for identification of the effect of premedication method on periprocedural thromboembolic events. The results of drug response assays of the preparation group were analyzed with respect to periprocedural thromboembolic events.

Results

No statistically significant difference in incidence of thromboembolic events was observed between the loading group and the preparation group. Analysis of the results of the drug response assay showed high prevalence (56.7%, 73.3%) of clopidogrel resistance and relatively low prevalence (6.7%) of aspirin resistance. Patients who had thromboembolic events tended to have lower responsiveness to both aspirin and clopidogrel than patients without it.

Conclusion

The method of antiplatelet premedication does not affect the rate of periprocedural thromboembolic events in coil embolization for treatment of an unruptured intracranial aneurysm. Nevertheless, considering the high prevalence of drug resistance, it is reasonable to premedicate antiplatelet agents in the preparation method for the drug response assay. Use of a higher dose of aspirin and clopidogrel or addition of an alternative drug (cilostazol or triflusal) can be applied against antiplatelet agent resistance. However, because the hemorrhagic risk associated with this supplementary use of antiplatelet agent has not been well-documented, the hemorrhagic risk and the preventive benefit must be weighed.

Triflusal reduces dense-core plaque load, associated axonal alterations and inflammatory changes, and rescues cognition in a transgenic mouse model of Alzheimer's disease

Inflammation has been associated with the two classic lesions in the Alzheimer's (AD) brain, amyloid deposits and neurofibrillary tangles. Recent data suggest that Triflusal, a compound with potent anti-inflammatory effects in the central nervous system in vivo, might delay the conversion from amnestic mild cognitive impairment to a fully established clinical picture of dementia. In the present study, we investigated the effect of Triflusal on brain Abeta accumulation, neuroinflammation, axonal curvature and cognition in an AD transgenic mouse model (Tg2576). Triflusal treatment did not alter the total brain Abeta accumulation but significantly reduced dense-cored plaque load and associated glial cell proliferation, proinflammatory cytokine levels and abnormal axonal curvature, and rescued cognitive deficits in Tg2576 mice. Behavioral benefit was found to involve increased expression of c-fos and BDNF, two of the genes regulated by CREB, as part of the signal transduction cascade underlying the molecular basis of long-term potentiation. These results add preclinical evidence of a potentially beneficial effect of Triflusal in AD.

Protective effects of triflusal on secondary thrombus growth and vascular cyclooxygenase-2

BACKGROUND

Carotid residual mural thrombus predisposes to recurrent thrombosis and/or distal embolization (i.e. cerebrovascular ischemia).

OBJECTIVES

Our aims were (i) to analyze and compare the efficacy of aspirin, triflusal, and its main metabolite 2-hydroxy-4-trifluorometylbenzoic acid (HTB) on secondary thrombus growth; and (ii) evaluate to what extent the three Cox-1 inhibitors influenced vascular Cox-1/Cox-2 expression and endothelial prostacyclin synthesis.

METHODS

In a rabbit model of ex vivo thrombosis, a fresh mural thrombus was formed on damaged vessels at flow conditions typical of mild and severe carotid stenoses. The effects of Cox-1 inhibitors administered both intravenously (i.v.) (aspirin 5 mg kg(-1), triflusal 10 mg kg(-1), and HTB 10 mg kg(-1)) and orally (p.o.) (8 days; aspirin 30 mg kg(-1) day(-1), and triflusal 40 mg kg(-1) day(-1)) on secondary thrombus growth were assessed by In-(111)deposited platelets and compared with a placebo control. Arterial Cox-1/Cox-2 expression after 8-day treatment was evaluated at mRNA and protein levels. Additionally, a drug-related dose-dependent in vitro assay was performed for endothelial PGI(2) release measurement (Cox-2 activity).

RESULTS

All Cox inhibitors similarly and significantly (P < 0.05) reduced secondary thrombus formation after i.v. and p.o. administration versus placebo control. Treatments exerted no effect on vascular Cox-1 mRNA whereas Cox-2 mRNA was moderately reduced by aspirin and triflusal (placebo 100% +/- 9%, aspirin 70% +/- 2% and triflusal 70% +/- 2%; P < 0.05). Cox-2 protein levels were slightly higher in the triflusal versus aspirin group (placebo 100% +/- 6%, aspirin 35% +/- 10% and triflusal 61% +/- 9%; P < 0.005 versus placebo). Interestingly, in vitro, HTB solely maintained endothelial PGI(2) synthesis levels similar to the control.

CONCLUSIONS

At a similar level of efficacy in inhibiting secondary thrombosis, triflusal seems to better preserve Cox-2 expression than aspirin and its metabolite HTB was able to protect endothelial prostacyclin production.

Amino acid conjugation: contribution to the metabolism and toxicity of xenobiotic carboxylic acids

Despite being the first conjugation reaction demonstrated in humans, amino acid conjugation as a route of metabolism of xenobiotic carboxylic acids is not well characterised. This is principally due to the small number and limited structural diversity of xenobiotic substrates for amino acid conjugation. Unlike CYP and uridine 5'-diphosphate glucuronosyltransferase, which are localised in the endoplasmic reticulum, the enzymes of amino acid conjugation reside in mitochondria. Unique among drug metabolism pathways, amino acid conjugation involves initial formation of a xenobiotic acyl-CoA thioester that is then conjugated principally with glycine in humans. However, formation of the xenobiotic acyl-CoA thioester does not always infer subsequent amino acid conjugation. Evidence is presented that in the absence of glycine conjugation substrates that form acyl-CoA thioesters perturb mitochondrial function. This review discusses literature on the enzymes involved and the concept that xenobiotic substrate selectivity provides a barrier to protect the metabolic integrity of the mitochondria.

The study of the influence of surfactant charge on alkaline hydrolysis reactions of acetylsalicylic acid (ASA) and triflusal (TFL) using spectrophotometric methods

In this research, the effects of micellar systems on alkaline hydrolysis reactions of acetylsalicylic acid (ASA) and triflusal (TFL) were found to be dependant upon the surfactant charge within the micelle. In cationic micelles, there is a catalytic effect at low concentrations of surfactant. However, this reaction is inhibited at higher surfactant concentrations. In anionic micelles, a catalytic effect occurs, while in zwitterionic and non-ionic micelles there is an inhibitory effect. Such reactions are attributable to changes in reactants on the micellar surface, or to the fact that both reactants are found in different microenvironments. The pseudophase (PS) and ion-exchange (PPIE) models were found to be consistent with the experimental result. Furthermore, the association constants for both drugs could be determined together with micellar rate constants in heterogeneous media.