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Background: Ticagrelor is a novel oral antiplatelet agent which can selectively inhibit P2Y12 receptor. Bleeding and dyspnea are common adverse reactions of ticagrelor in clinic. The side effects of ticagrelor are correlated with the plasma concentration of ticagrelor., Objective: This study aimed to evaluate the catalytic characteristics of 22 CYP3A4 alleles identified in the Chinese Han population on the metabolism of ticagrelor in vitro , focusing on the effect of CYP3A4 polymorphism on ticagrelor metabolism., Methods: In this study, insect cells were used to express 22 CYP3A4 variants, which were then incubated with 1-50 µM ticagrelor at 37 °C for 30 minutes to obtain the metabolite (AR-C124910XX). AR-C124910XX was detected by UHPLC-MS/MS to calculate the kinetic parameters, including Km, Vmax and CLint., Results: Compared to the wild-type, most CYP3A4 alleles exhibited significant differences in intrinsic clearance. The intrinsic clearance of CYP3A4*11, *18 and *33 was much higher than that of wild-type; four variants exhibited similar intrinsic clearance values as the wild-type enzyme; The remaining 14 variants showed significantly reduced intrinsic clearance values, ranging from 1.48% to 75.11% of the wild-type; CYP3A4*30 displayed weak or no activity., Conclusion: This study conducted a comprehensive assessment of the effect of CYP3A4 variants on ticagrelor's metabolism. The results suggested that there is allele-specific activity towards ticagrelor in vitro . These findings can provide some insights and predictions for treatment strategies and risk assessments associated with ticagrelor in clinical practice., Competing Interests: The authors declare there are no competing interests., (©2024 Hu et al.)

Objectives: This study aimed to understand the pharmacokinetics of ticagrelor in Chinese patients with acute coronary syndrome (ACS), identify influencing factors, and inform ticagrelor treatment optimization., Materials and Methods: Data from 195 ACS patients, including 491 plasma ticagrelor concentration timepoints and clinical information, were analyzed using NONMEN for pharmacokinetic (PK) parameter factors. The model underwent internal validation with bootstrap methodology., Results: The PK curve of ticagrelor was well delineated using a one disposition compartment model with first-order absorption rate constant, 0.67/h. When the direct bilirubin levels and white plasma cell counts increased, female patients showed decreased glomerular filtration rate, decreased ticagrelor clearance rate, and increased exposure. When the direct bilirubin levels increased and body weight and hemoglobin decreased, rs6787801 was GG compared with AA and GA, the ticagrelor metabolite clearance rate decreased and exposure increased., Conclusion: The study offers key insights into ticagrelor's dose-exposure relationship post-percutaneous coronary intervention in ACS patients, highlighting factors critical for personalized treatment strategies.

Introduction: Aspirin and anti-P2Y12 are widely prescribed in cardiovascular patients, often in combination with proton pump inhibitors (PPIs) to limit the risk of upper gastrointestinal bleedings. The potential interaction between PPIs and antiplatelet agents has been widely discussed, but doubts remain as to whether PPIs may reduce the cardiovascular protection provided by aspirin, prasugrel, ticagrelor, and clopidogrel., Areas Covered: Many pharmacokinetic (PK) and pharmacodynamic (PD) studies have confirmed the interaction, especially between PPIs and clopidogrel, but with uncertain consequences on clinical outcomes. Therefore, we aimed to summarize the evidence for the widespread combined use of oral antiplatelet drugs and PPIs, to outline the current evidence supporting or opposing drug-drug interaction, and to discuss the clinical implications of such interactions., Expert Opinion: A large body of evidence describes the PK/PD interaction of antiplatelet drugs with PPIs and its potential role in increasing clinical cardiovascular adverse events, but no solid clinical data have confirmed these effects. In the light of the published studies, there seems to be no restriction on the choice of PPI with aspirin, prasugrel, and/or ticagrelor. The choice of a PPI with no (or minimal) interference with the hepatic cytochrome P450 2C19 is preferred in patients receiving clopidogrel.

Background: ADP and ATP are importantly involved in vascular and thrombotic homeostasis, via multiple receptor pathways. Blockade of ADP P2Y 12 receptors inhibits platelet aggregation and represents an effective cardiovascular disease prevention strategy. AZD3366 (APT102), a long-acting recombinant form of an optimized CD39L3 human apyrase, has effectively reduced ATP, ADP, and platelet aggregation and provided tissue protection in preclinical models, features that could be very beneficial in treating patients with cardiovascular disease., Methods and Results: We conducted this phase 1, first-in-human study of single ascending doses of intravenous AZD3366 or placebo, including doses added to dual antiplatelet therapy with ticagrelor and acetylsalicylic acid. The primary objective was safety and tolerability; secondary and exploratory objectives included pharmacokinetics, pharmacodynamics (measured as inhibition of platelet aggregation), adenosine diphosphatase (ADPase) activity, and ATP/ADP metabolism. In total, 104 participants were randomized. AZD3366 was generally well tolerated, with no major safety concerns observed. ADPase activity increased in a dose-dependent manner with a strong correlation to AZD3366 exposure. Inhibition of ADP-stimulated platelet aggregation was immediate, substantial, and durable. In addition, there was a prompt decrease in systemic ATP concentration and an increase in adenosine monophosphate concentrations, whereas ADP concentration appeared generally unaltered. At higher doses, there was a prolongation of capillary bleeding time without detectable changes in the ex vivo thromboelastometric parameters., Conclusions: AZD3366 was well tolerated in healthy participants and demonstrated substantial and durable inhibition of platelet aggregation after single dosing. Higher doses prolonged capillary bleeding time without detectable changes in ex vivo thromboelastometric parameters., Registration: URL: https://www.clinicaltrials.gov; Unique Identifier: NCT04588727.

Purpose: P2Y 12 receptor inhibitors are drugs that decrease the risk of stent thrombosis and lower the long-term risk of non-stent-related myocardial infarction and stroke. They inhibit the binding of adenosine diphosphate (ADP) to the P2Y 12 receptor and effectively reduce platelet reactivity. However, considerable variability in the pharmacodynamics response contributes to a failure of antiplatelet therapy; this phenomenon is especially notorious for older drugs, such as clopidogrel. Some genetic polymorphisms associated with these drugs' metabolic pathway, especially in the CYP2C19 gene, can significantly decrease antiplatelet efficacy. There are few reports on the variability stemming from the target of this drug class that is the P2Y 12 receptor itself., Results and Conclusion: This review summarizes the results of research that focus on the influence of P2Y 12 genetic polymorphisms on the pharmacodynamics and the efficacy of P2Y 12 inhibitors. We found that the conclusions of the studies are unequivocal, and despite several strong candidates, such as G52T (rs6809699) or T744C (rs2046934), they may not be independent predictors of the inadequate response to the drug. Most probably, P2Y 12 genetic polymorphisms contribute to the effect exerted by other gene variants (such as CYP2C19*2/*3/*17), drug interactions, or patient habits, such as smoking. Also, epigenetic modifications, such as methylation or miRNA levels, may play a role in the efficacy of antiplatelet treatment., (© 2022. The Author(s).)

Background: The P2Y 12 receptor antagonist selatogrel is being developed for subcutaneous self-administration with a ready-to-use autoinjector at the onset of acute myocardial infarction (AMI) symptoms. The unique pharmacological profile of selatogrel (fast, potent, and short-acting) can bridge the time gap between the onset of AMI and first medical care. A clinical Phase 1 study showed a time-dependent pharmacodynamic interaction between selatogrel and loading doses of clopidogrel and prasugrel. As treatment switching is a common clinical practice, the assessment of subsequent switching from a clopidogrel loading dose to the first maintenance dose of oral P2Y 12 receptor antagonists is highly relevant. Objectives: Model-based predictions of inhibition of platelet aggregation (IPA) for the drugs triggering pharmacodynamic interactions were to be derived to support clinical guidance on the transition from selatogrel to oral P2Y 12 receptor antagonists. Methods: Scenarios with selatogrel 16 mg administration or placebo followed by a clopidogrel loading dose and, in turn, prasugrel or ticagrelor maintenance doses at different times of administration were studied. Population pharmacokinetic/pharmacodynamic modeling and simulations of different treatment scenarios were used to derive quantitative estimates for IPA over time. Results: Following selatogrel/placebo and a clopidogrel loading dose, maintenance treatment with ticagrelor or a prasugrel loading dose followed by maintenance treatment quickly achieved sustained IPA levels above 80%. Prior to maintenance treatment, a short time span from 18 to 24 h was identified where IPA levels were predicted to be lower with selatogrel than with placebo if clopidogrel was administered 12 h after selatogrel or placebo. Predicted IPA levels reached with placebo alone and a clopidogrel loading dose at 4 h were consistently lower than with selatogrel administration, followed by a clopidogrel loading dose at 12 h. If a clopidogrel loading dose is administered at 12 h, selatogrel maintains higher IPA levels up to 16 h. IPA levels are subsequently lower than on the placebo until the administration of the first maintenance dose. Conclusions: Model-based predictions informed the transition from selatogrel subcutaneous administration to oral P2Y 12 therapy. The application of modeling techniques illustrates the value of employing pharmacokinetic and pharmacodynamic modeling for the simulation of various clinical scenarios of switching therapies.

Antiplatelet agents are among the most frequently used medications in cardiovascular medicine. Although in patients with atherosclerotic disease manifestations, in particular those treated by percutaneous coronary intervention, antiplatelet agents are beneficial for the prevention of ischemic events, they inevitably increase the risk of bleeding. Furthermore, 5-15% of patients treated by percutaneous coronary intervention may need a surgical procedure within 2 years, creating challenges to safe and effective antiplatelet drug management. Importantly, major spontaneous or procedural-related bleedings are associated with increased hospital admission, length, costs, and poor prognosis. Although the effects of other antithrombotic therapies, such as direct oral anticoagulants, can be reversed by approved specific agents, there are no approved reversal agents for any antiplatelet drugs. The fact that many antiplatelet agents, such as aspirin and thienopyridines (i.e., clopidogrel and prasugrel), bind irreversibly to their targets represents a challenge for the development of a drug-specific reversal agent. In contrast, ticagrelor is a non-thienopyridine with a plasma half-life of 7-9 h that reversely binds the P2Y 12 receptor producing potent signaling blockage. In 2015, bentracimab (also known as PB2452 or MEDI2452), a neutralizing monoclonal antibody fragment that binds free plasma ticagrelor and its major active metabolite, was identified. This systematic overview provides a comprehensive summary of the drug development program of bentracimab, focusing on its pharmacodynamic, pharmacokinetic, and safety profiles., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Ticagrelor has multiple indications, including for some patients with chronic coronary syndromes (CCS) at high risk of ischaemic events. Body mass can potentially affect pharmacodynamics (PD) and pharmacokinetics (PK). We investigated the influence of body mass (range 53-172 kg, 20.8-46.9 kg/m 2 ) on PD/PK in 221 CCS patients receiving ticagrelor 60 mg or 90 mg twice-daily (BD) during two randomised-controlled trials. Correlations between body weight (BW) or body mass index (BMI) and PD/PK measurements obtained during maintenance treatment at trough ('pre-dose') and peak effect ('post-dose') were assessed. BW and BMI correlated with P2Y 12 reactivity units at pre-dose (e.g. BW:R = 0.26, p = 0.008) but not post-dose timepoints. BW affected ticagrelor active metabolite (TAM) levels (e.g. 60 mg BD, post-dose:R = -0.39, p < 0.0001) and there was evidence of an inverse power law relationship between BW and TAM-to-ticagrelor ratio. PK with ticagrelor 60 mg correlated significantly with BMI. BW and BMI did not affect the chance of high platelet reactivity, which remained very low across the whole cohort. There was no difference in PRU between the two doses of ticagrelor within each weight or BMI group. Body mass has modest effects on the PK/PD response to ticagrelor in patients with CCS but currently-used regimens appear adequate across the range of BW/BMI studied., Competing Interests: Declaration of Competing Interest W.A.E. Parker reports institutional research grants and personal fees from AstraZeneca. D.J. Angiolillo has received consulting fees or honoraria from Abbott, Amgen, Aralez, AstraZeneca, Bayer, Biosensors, Boehringer Ingelheim, Bristol Myers Squibb, Chiesi, Daiichi-Sankyo, Eli Lilly, Haemonetics, Janssen, Merck, PhaseBio, PLx Pharma, Pfizer, Sanofi, and The Medicines Company; has received payments for participation in review activities from CeloNova and St Jude Medical; and his institution has received research grants from Amgen, AstraZeneca, Bayer, Biosensors, CeloNova, CSL Behring, Daiichi-Sankyo, Eisai, Eli Lilly, Gilead, Idorsia, Janssen, Matsutani Chemical Industry Co, Merck, Novartis, Osprey Medical, Renal Guard Solutions, and the Scott R. MacKenzie Foundation. F. Rollini declares that he has received honoraria from Chiesi. F. Franchi. declares that he has received consulting fees or honoraria from AstraZeneca, Bayer and Sanofi. He also declares that has received research grants from PLx Pharma and Scott R. MacKenzie Foundation. M.P. Bonaca is the Executive Director of CPC, a non-profit academic research organization affiliated with the University of Colorado, that receives research grant/consulting funding from: Abbott, Agios, Alexion Pharma, Alnylam, Amgen, Angionetics, ARCA Biopharma, Array, AstraZeneca, Atentiv, Audentes, Bayer, Better Therapeutics, Brigham and Women's Hospital, Bristol-Myers Squibb, Cardiol Therapeutics, CellResearch, Cook Medical, Cook, CSL Behring, Eidos Therapeutics, EP Trading Co, Esperion Therapeutics, EverlyWell, Faraday, Fortress Biotech, HDL Therapeutics, Heartflow, Hummingbird Bioscience, Insmed, Janssen, Kowa Research, Lexicon, Merck, Medtronic, Moderna, Novate Medical, NovoNordisk, Pfizer, PhaseBio, PPD Development, Prairie Education and Research, Prothena Ciosciences, Regeneron, Regio Biosciences, Sanifit Therapeutics, Sanofi, Smith and Nephew, Stealth BioTherapeutics, University of Colorado, Worldwide Clinical Trials, Wraser, Yale Cardiovascular Research Group. Dr. Bonaca also reports stock in Medtronic and Pfizer and consulting fees from Audentes. D.L. Bhatt discloses the following relationships - Advisory Board: AngioWave, Bayer, Boehringer Ingelheim, Cardax, CellProthera, Cereno Scientific, Elsevier Practice Update Cardiology, Janssen, Level Ex, Medscape Cardiology, Merck, MyoKardia, NirvaMed, Novo Nordisk, PhaseBio, PLx Pharma, Regado Biosciences, Stasys; Board of Directors: AngioWave (stock options), Boston VA Research Institute, DRS.LINQ (stock options), Society of Cardiovascular Patient Care, TobeSoft; Chair: Inaugural Chair, American Heart Association Quality Oversight Committee; Data Monitoring Committees: Acesion Pharma, Assistance Publique-Hôpitaux de Paris, Baim Institute for Clinical Research (formerly Harvard Clinical Research Institute, for the PORTICO trial, funded by St. Jude Medical, now Abbott), Boston Scientific (Chair, PEITHO trial), Cleveland Clinic (including for the ExCEED trial, funded by Edwards), Contego Medical (Chair, PERFORMANCE 2), Duke Clinical Research Institute, Mayo Clinic, Mount Sinai School of Medicine (for the ENVISAGE trial, funded by Daiichi Sankyo; for the ABILITY-DM trial, funded by Concept Medical), Novartis, Population Health Research Institute; Rutgers University (for the NIH-funded MINT Trial); Honoraria: American College of Cardiology (Senior Associate Editor, Clinical Trials and News, ACC.org; Chair, ACC Accreditation Oversight Committee), Arnold and Porter law firm (work related to Sanofi/Bristol-Myers Squibb clopidogrel litigation), Baim Institute for Clinical Research (formerly Harvard Clinical Research Institute; RE-DUAL PCI clinical trial steering committee funded by Boehringer Ingelheim; AEGIS-II executive committee funded by CSL Behring), Belvoir Publications (Editor in Chief, Harvard Heart Letter), Canadian Medical and Surgical Knowledge Translation Research Group (clinical trial steering committees), Cowen and Company, Duke Clinical Research Institute (clinical trial steering committees, including for the PRONOUNCE trial, funded by Ferring Pharmaceuticals), HMP Global (Editor in Chief, Journal of Invasive Cardiology), Journal of the American College of Cardiology (Guest Editor; Associate Editor), K2P (Co-Chair, interdisciplinary curriculum), Level Ex, Medtelligence/ReachMD (CME steering committees), MJH Life Sciences, Oakstone CME (Course Director, Comprehensive Review of Interventional Cardiology), Piper Sandler, Population Health Research Institute (for the COMPASS operations committee, publications committee, steering committee, and USA national co‑leader, funded by Bayer), Slack Publications (Chief Medical Editor, Cardiology Today's Intervention), Society of Cardiovascular Patient Care (Secretary/Treasurer), WebMD (CME steering committees), Wiley (steering committee); Other: Clinical Cardiology (Deputy Editor), NCDR-ACTION Registry Steering Committee (Chair), VA CART Research and Publications Committee (Chair); Research Funding: Abbott, Acesion Pharma, Afimmune, Aker Biomarine, Amarin, Amgen, AstraZeneca, Bayer, Beren, Boehringer Ingelheim, Boston Scientific, Bristol-Myers Squibb, Cardax, CellProthera, Cereno Scientific, Chiesi, CSL Behring, Eisai, Ethicon, Faraday Pharmaceuticals, Ferring Pharmaceuticals, Forest Laboratories, Fractyl, Garmin, HLS Therapeutics, Idorsia, Ironwood, Ischemix, Janssen, Javelin, Lexicon, Lilly, Medtronic, Merck, Moderna, MyoKardia, NirvaMed, Novartis, Novo Nordisk, Owkin, Pfizer, PhaseBio, PLx Pharma, Recardio, Regeneron, Reid Hoffman Foundation, Roche, Sanofi, Stasys, Synaptic, The Medicines Company, 89Bio; Royalties: Elsevier (Editor, Braunwald's Heart Disease); Site Co-Investigator: Abbott, Biotronik, Boston Scientific, CSI, Endotronix, St. Jude Medical (now Abbott), Philips, Svelte, Vascular Solutions; Trustee: American College of Cardiology; Unfunded Research: FlowCo, Takeda. P.G.Steg reports receiving research grants from Bayer, Merck, Sanofi, Servier and receiving consulting fees or honoraria from Amarin, Amgen, AstraZeneca, Bayer, Bristol-Myers-Squibb, Janssen, Kowa, Idorsia, Lexicon, Merck, Novartis, Novo-Nordisk, PhaseBio, Pfizer, Regeneron, Sanofi, Servier. M. R. Thomas reports institutional research grants from Novartis, Sanofi, Rigel and Acticor Pharmaceuticals and consultancy fees from Cytosorbents. M. S. Sabatine reports research grant support through Brigham and Women's Hospital from: Abbott; Amgen; Anthos Therapeutics; AstraZeneca; Bayer; Daiichi-Sankyo; Eisai; Intarcia; Ionis; Medicines Company; MedImmune; Merck; Novartis; Pfizer; Quark Pharmaceuticals. Consulting for: Althera; Amgen; Anthos Therapeutics; AstraZeneca; Beren Therapeutics; Bristol-Myers Squibb; DalCor; Dr. Reddy's Laboratories; Fibrogen; Intarcia; Merck; Moderna; Novo Nordisk; and Silence Therapeutics. R.F. Storey reports institutional research grants and personal fees from AstraZeneca, Cytosorbents, GlyCardial Diagnostics and Thromboserin; and personal fees from Alnylam, Bayer, Bristol Myers Squibb/Pfizer, Chiesi, CSL Behring, Hengrui, Idorsia, Novartis, PhaseBio, Portola, and Sanofi Aventis. The other authors have no relevant disclosures., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Ticagrelor is one of the most recent antiplatelet agents used to inhibit platelet aggregation via blocking the ADP receptors of the subtype P2Y 12 . It belongs to the non-thienopyridine class. The drug was first discovered by Astra Zeneca and approved for use in 2011 by the FDA. Ticagrelor is usually used for the prevention and treatment of thromboembolism in adult patients with acute coronary syndrome. This chapter include an overview on the physical properties, chemical properties, mode of action, pharmacokinetics and common uses of ticagrelor. In addition, the reported methods of ticagrelor assay will be discussed briefly in order to help analysts to find the most convenient method for its estimation in routine analysis. The methods of synthesis used for the preparation of ticagrelor will also be covered in this chapter. Moreover, the analytical and characterization techniques used to characterize ticagrelor row material are summarized herein., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Vicagrel, a novel irreversible P2Y 12 receptor inhibitor, is undergoing phase III trials for the treatment of acute coronary syndromes in China. In this study, we evaluated the pharmacokinetics, mass balance, and metabolism of vicagrel in six healthy male Chinese subjects after a single oral dose of 20 mg [ 14 C]vicagrel (120 µCi). Vicagrel absorption was fast (T max  = 0.625 h), and the mean t 1/2 of vicagrel-related components was ~38.0 h in both plasma and blood. The blood-to-plasma radioactivity AUC inf ratio was 0.55, suggesting preferential distribution of drug-related material in plasma. At 168 h after oral administration, the mean cumulative excreted radioactivity was 96.71% of the dose, including 68.03% in urine and 28.67% in feces. A total of 22 metabolites were identified, and the parent vicagrel was not detected in plasma, urine, or feces. The most important metabolic spot of vicagrel was on the thiophene ring. In plasma pretreated with the derivatization reagent, M9-2, which is a methylated metabolite after thiophene ring opening, was the predominant drug-related component, accounting for 39.43% of the radioactivity in pooled AUC 0-8 h plasma. M4, a mono-oxidation metabolite upon ring-opening, was the most abundant metabolite in urine, accounting for 16.25% of the dose, followed by M3-1, accounting for 12.59% of the dose. By comparison, M21 was the major metabolite in feces, accounting for 6.81% of the dose. Overall, renal elimination plays a crucial role in vicagrel disposition, and the thiophene ring is the predominant metabolic site., (© 2020. CPS and SIMM.)

Selatogrel is a potent and reversible P2Y 12 receptor antagonist developed for subcutaneous self-administration by patients with suspected acute myocardial infarction. After single-dose emergency treatment with selatogrel, patients are switched to long-term treatment with oral P2Y 12 receptor antagonists. Selatogrel shows rapid onset and offset of inhibition of platelet aggregation (IPA) to overcome the critical initial time after acute myocardial infarction. Long-term benefit is provided by oral P2Y 12 receptor antagonists such as clopidogrel, prasugrel, and ticagrelor. A population pharmacokinetic (PK)/pharmacodynamic (PD) model based on data from 545 subjects in 4 phase I and 2 phase II studies well described the effect of selatogrel on IPA alone and in combination with clopidogrel, prasugrel, and ticagrelor. The PK of selatogrel were described by a three-compartment model. The PD model included a receptor-pool compartment to which all drugs can bind concurrently, reversibly or irreversibly, depending on their mode of action. Furthermore, ticagrelor and its active metabolite can bind to the selatogrel-receptor complex allosterically, releasing selatogrel from the binding site. The model provided a framework for predicting the effect on IPA of selatogrel followed by reversibly and irreversibly binding oral P2Y 12 receptor antagonists for sustained effects. Determining the timepoint for switching from emergency to maintenance treatment is critical to achieve sufficient IPA at all times. Simulations based on the interaction model showed that loading doses of clopidogrel and prasugrel administered 15 h and 4.5 h after selatogrel, respectively, provide sustained IPA with clinically negligible drug interaction. Study Highlights WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC? Selatogrel is a potent reversible P2Y 12 receptor antagonist developed for subcutaneous self-administration by patients in case of suspected acute myocardial infarction. Transition to oral P2Y 12 receptor antagonists without drug interaction and sufficient inhibition of platelet aggregation must be assured at all times. WHAT QUESTION DID THIS STUDY ADDRESS? The pharmacokinetic/pharmacodynamic model semimechanistically describes the effect of selatogrel on platelet inhibition alone and in combination with the oral P2Y 12 receptor antagonists clopidogrel, prasugrel, and ticagrelor. WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE? Model-based simulations showed that loading doses of clopidogrel and prasugrel can be administered from 15 h and 4.5 h after selatogrel, respectively. HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE? These results support guiding the clinical transition from selatogrel emergency treatment to oral maintenance therapy in a safe and efficacious way., (© 2021 The Authors. CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Prasugrel and ticagrelor are potent oral platelet P2Y 12 inhibitors and are recommended over clopidogrel in patients with acute coronary syndrome (ACS). Oral platelet P2Y 12 inhibitors are characterized by varying degrees of pharmacodynamic response profiles as assessed by a variety of commercially available assays. Because of its ease of use, rapid turnaround times and ability to provide results specific to P2Y 12 inhibitory effects, VerifyNow has emerged as one of the most commonly utilized platelet function assays. However, reference ranges with VerifyNow have been reported mainly for clopidogrel and there has not yet been any study specifically conducted to provide the expected on treatment reference ranges following administration of prasugrel and ticagrelor. This was a prospective single center investigation conducted in 120 patients with ACS who were treated with prasugrel or ticagrelor as per standard of care. Patients who underwent percutaneous coronary interventions (PCI) were treated with a loading dose of prasugrel (60 mg) or ticagrelor (180 mg), and patients who were on maintenance therapy were taking prasugrel (10 mg qd or 5 mg qd) or ticagrelor (90 mg bid). Platelet function testing was performed using the VerifyNow™ PRUTest™. The overall range of PRUTest values was lower than that observed in studies of patients treated with clopidogrel. The use of a maintenance dose regimen had a wider range of PRUTest values compared to the use of a loading dose for both prasugrel (1-179 vs. 2-128) and ticagrelor (1-196 vs. 1-177). The average PRUTest values in patients on prasugrel and ticagrelor maintenance dosing were 20% and 9% higher those observed in patients treated with a loading dose. PRUTest results following loading dose administration were very similar between drugs, but were 20% higher with prasugrel compared with ticagrelor during maintenance dosing. This study establishes expected PRUTest ranges for patients taking loading and maintenance doses of prasugrel and ticagrelor.Clinical Trial Registration http://www.clinicaltrials.gov Unique Identifier: NCT04492423, registered July 2020 retrospectively registered.

Despite advances in medical and interventional management of acute myocardial infarction, treatment of the associated chest pain has remained relatively unchanged since opioids were first utilized in the 1930's. This dominance can be partially attributed to initial studies suggesting hemodynamic benefits with opioid treatment. However, delayed gastrointestinal absorption of P2Y 12 inhibitors due to opioids and the consequent impairment in antiplatelet activity of this established therapy is cause for concern. Coupled with the lack of randomized clinical trial evidence to support widespread opioid use, there is now an opportunity to re-evaluate our approach to analgesia in myocardial infarction. This review characterizes the mechanism of the opioid-P2Y 12 inhibitor interaction, strategies aimed at mitigating the interaction and appraises promising alternative agents to opioid therapy in patients with myocardial infarction., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Herbs usually contain a mixture of biologically active constituents, which can interact with numerous prescribed drugs and alter their safety profiles., Objectives: The current investigation was aimed to evaluate the effect of commonly used herbal products including black seed (Nigella sativa), garden cress (Lepidium sativum), and fenugreek (Trigonella foenum-graecum) on the pharmacokinetics and pharmacodynamics of clopidogrel using a Wistar rat model., Methods: A GC-MS analysis revealed the presence of several phytoconstitutents (polyphenols) in the extracts of black seed, garden cress, and fenugreek. These polyphenols have the potential to interfere with clopidogrel effect. Plasma concentrations of clopidogrel were measured at different time points in the absence and presence of the concurrent use of tested herbal products and the pharmacokinetic parameters were calculated. Bleeding time was measured in various groups as a measure of the antiplatelet effect of clopidogrel., Results: Area under the plasma concentration-time curves (AUC0-∞) of clopidogrel were 35.53 ±0.89 μg/ml*h (p<0.05), 26.01 ±0.90 μg/ml*h (p>0.05) and 32.80 ±2.51 μg/ml*h (p<0.05) in the black seed, garden cress and fenugreek group, respectively, compared with that of the control group (27.02 ±0.42 μg/ml*h). Treatment with black seed also caused an increase in clopidogrel Cmax by 31.52% (p<0.05) and with fenugreek by 21.42% (p<0.05); Cmax, did not changed with garden cress treatment (6.48 ±0.15 μg/ml versus 6.12 ±0.21 μg/ml, p>0.05). The pharmacodynamic evaluation of the antiplatelet effect of clopidogrel in the presence of herbal products treatment showed a significant prolongation in the bleeding time from a control baseline by ~22-26%, and by added ~8-12% in reference to clopidogrel therapeutic effect (p<0.05)., Conclusion: The concurrent use of black seed, fenugreek, or garden cress can alter the pharmacokinetics and pharmacodynamics of clopidogrel to varying degrees due to the presence of various bioactive polyphenols. This is probably due to changes in drug disposition and its antiplatelet action. Further confirmation can determine the clinical relevance of these observations and identify the exact constituents responsible for such activities., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Rapid phosphoester hydrolysis of endogenous purine and pyrimidine nucleotides has challenged the characterization of the role of P2 receptors in physiology and pathology. Nucleotide phosphoester stabilization has been pursued on a number of medicinal chemistry fronts. We investigated the in vitro and in vivo stability and pharmacokinetics of prototypical nucleotide P2Y 1 receptor (P2Y 1 R) agonists and antagonists. These included the riboside nucleotide agonist 2-methylthio-ADP and antagonist MRS2179, as well as agonist MRS2365 and antagonist MRS2500 containing constrained (N)-methanocarba rings, which were previously reported to form nucleotides that are more slowly hydrolyzed at the α-phosphoester compared with the ribosides. In vitro incubations in mouse and human plasma and blood demonstrated the rapid hydrolysis of these compounds to nucleoside metabolites. This metabolism was inhibited by EDTA to chelate divalent cations required by ectonucleotidases for nucleotide hydrolysis. This rapid hydrolysis was confirmed in vivo in mouse pharmacokinetic studies that demonstrate that MRS2365 is a prodrug of the nucleoside metabolite AST-004 (MRS4322). Furthermore, we demonstrate that the nucleoside metabolites of MRS2365 and 2-methylthio-ADP are adenosine receptor (AR) agonists, notably at A 3 and A 1 ARs. In vivo efficacy of MRS2365 in murine models of traumatic brain injury and stroke can be attributed to AR activation by its nucleoside metabolite AST-004, rather than P2Y 1 R activation. This research suggests the importance of reevaluation of previous in vitro and in vivo research of P2YRs and P2XRs as there is a potential that the pharmacology attributed to nucleotide agonists is due to AR activation by active nucleoside metabolites.

This study aimed at exploring the potential mechanism of decreased in vivo exposure of the antiplatelet agent, ticagrelor and its active metabolite, AR-C124910XX, mediated by tea polyphenols, which was first revealed by our previous study, as well as predicting the in vivo drug-drug interaction (DDI) potential utilizing an in vitro to in vivo extrapolation (IVIVE) approach. The bidirectional transport and uptake kinetics of ticagrelor were determined using Caco-2 cells. Inhibition potency of major components of tea polyphenols, epigallocatechin gallate (EGCG) and epigallocatechin (EGC) were obtained from Caco-2 cells, human intestinal and hepatic microsomes (HIMs and HLMs) in vitro. A mean efflux ratio of 2.28 ± 0.38 and active uptake behavior of ticagrelor were observed in Caco-2 cell studies. Further investigation showed that the IC 50 values of EGCG and EGC on the uptake of ticagrelor were 42.0 ± 5.1 μM (95% CI 31.9-54.8 μM) and 161 ± 13 μM (95% CI 136-191 μM), respectively. EGCG and EGC also displayed moderate to weak reversible inhibition on the formation of AR-C124910XX and the inactive metabolite, AR-C133913XX in HIMs and HLMs, while no clinically significant time-dependent inhibition was observed for either compound. IVIVE indicated a significant inhibition effect of EGCG on the uptake process of ticagrelor, while no potential DDI risk was found based on microsomal data. A 45% decrease in ticagrelor in vivo exposure was mechanistically predicted by incorporating intestinal and hepatic metabolism as well as intestinal absorption. This dual inhibition of tea polyphenols on ticagrelor revealed the underlying potential of transporter-enzyme interplay, in which the altered uptake process was more critical., (Copyright © 2020. Published by Elsevier B.V.)

Fentanyl is a potent synthetic opioid used to alleviate severe and chronic pain, as well as an adjunct to general or local anesthesia. Although fentanyl has been used for decades, its full effects are still unknown. Its analgesic and anesthetic activity arises from the stimulation of μ-opioid receptors, resulting in the inhibition of adenyl cyclase and downregulation of cyclic adenosine 3',5'-monophosphate (cAMP), as well as decreased calcium channel activity and increased potassium channel activity. The μ-opioid receptors are abundantly distributed within the central nervous system, where they mediate analgesia, and in the nerve cells of the intestines, where they regulate gastrointestinal tract motility in the secretion or transport of fluids and electrolytes. They are also expressed in blood cells, blood vessel cells, and skin. Given the widespread distribution of μ-opioid receptors, it is likely that fentanyl may also regulate the activity of many other cells, including platelets. Recent findings indicate that it may impair the action of ticagrelor: an oral P2Y12 receptor inhibitor acting as an antiplatelet drug. It could pose a risk of insufficient platelet inhibition and result in thrombotic complications in patients with coronary artery disease. This article tackles the issue of fentanyl interactions with antiplatelet drugs. The mechanism of this phenomenon is not fully understood. Similarly, the biological effects exerted by fentanyl on platelets and the presence of opioid receptors on the platelet surface remain an open question.

In vitro studies have indicated that the P2Y12 receptor antagonist selatogrel is a substrate of organic anion-transporting-polypeptide (OATP)1B1 and OATP1B3 that are known to mediate hepatic uptake. Selatogrel is primarily eliminated via the biliary route. Therefore, the study aim was to investigate the effect of rifampin-mediated OATP1B1 and OATP1B3 inhibition on the pharmacokinetics (PK) of selatogrel. This was a randomized, double-blind, placebo-controlled, two-period, crossover study in 14 healthy subjects. In each period, a single subcutaneous dose of 4 mg selatogrel was administered, either immediately after a single intravenous 30 minutes infusion of 600 mg rifampin or after placebo. Plasma samples were collected for 36 hours and analyzed using a validated liquid chromatography-tandem mass spectrometry method. PK parameters of selatogrel were calculated using noncompartmental analysis. The effect of rifampin was explored based on geometric mean peak plasma concentration (C max ) and area under the concentration curve from zero to infinity (AUC 0-∞ ) ratios and for time of maximum plasma concentration (T max ) by Wilcoxon signed rank test. In addition, the safety and tolerability of the study treatments were evaluated. The geometric mean ratios of C max and AUC 0-∞ were 1.19 (90% confidence interval (CI) 1.11-1.28) and 1.43 (90% CI 1.36-1.51), respectively, indicating a minor selatogrel exposure increase when administered after an infusion of rifampin compared with placebo. Rifampin administration did not affect terminal half-life (t ½ ) or T max of selatogrel. All study treatments were safe and well-tolerated. A single dose of 600 mg rifampin, a potent OATP1B1/1B3 inhibitor, did not impact the PK of selatogrel to a clinically relevant extent suggesting that OATP1B1 and OATP1B3 transporters do not play a major role in the elimination of selatogrel., (© 2020 Idorsia Pharmaceuticals Ltd. Clinical and Translational Science published by Wiley Periodicals, Inc. on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Opiates are the traditional analgesics used in patients with ST-elevation myocardial infarction (STEMI). Pharmacodynamic studies indicate that opiates delay the absorption of orally administered P2Y 12 inhibitors and the onset of platelet inhibition. Whether these negative effects on platelet inhibition have an impact on clinical outcomes is unclear. A systematic review and meta-analysis was performed searching PubMed, MEDLINE, and Cochrane Central Register of Controlled Trials to identify studies comparing morphine and no-morphine treatment in STEMI patients undergoing primary percutaneous coronary intervention. The primary end point was the occurrence of in-hospital myocardial infarction, and secondary end points were in-hospital stroke and death. Four observational studies were identified, including 3,220 patients with STEMI. Morphine-treated patients had a higher unadjusted rate of reinfarction compared with patients not receiving morphine (1.5% vs. 0.67%, odds ratio (OR) 2.41; 95% confidence interval (CI), 1.11-5.21; P = 0.03). Unadjusted mortality rate was lower in morphine-treated patients (1.7% vs. 4.2%, OR 0.43, 95% CI, 0.23-0.81; P = 0.009). Exclusion of the study with baseline differences between groups showed more frequent reinfarction in the morphine group, but this was no longer statistically significant (1.3% vs. 0.5%, OR 2.02; 95% CI, 0.39-10.43; P = 0.40). There was no difference in stroke according to morphine treatment. Patients pretreated with morphine appear to have a higher rate of reinfarction than patients not receiving morphine. This may be attributable to opiate-related delay in P2Y 12 inhibitor absorption and resultant delay in onset of platelet inhibition. These concerning findings indicate the need for prospective, randomized trials to assess the impact of opiates on clinical outcomes in STEMI., (© 2020 The Authors Clinical Pharmacology & Therapeutics © 2020 American Society for Clinical Pharmacology and Therapeutics.)

Introduction: Platelet P2Y 12 inhibitors have a key role in reducing thrombotic complications in patients undergoing percutaneous coronary intervention (PCI) and those with acute coronary syndrome (ACS). Clopidogrel, prasugrel and ticagrelor are widely prescribed oral P2Y 12 receptor antagonists, but numerous clinical and pharmacological factors can lead to impaired gastrointestinal absorption resulting in reduced antithrombotic protection. These observations underscore the need for novel compounds or routes of administration that enable more favorable pharmacokinetic and pharmacodynamic profiles while reducing the risk for thrombotic complications., Areas Covered: Selatogrel, formerly known as ACT-246475, is a novel, potent, reversible, and selective non-thienopyridine antagonist of the P2Y 12 receptor developed for subcutaneous administration. Results from preclinical, Phase 1 and 2 studies have shown selatogrel to have rapid absorption and sustained and reversible platelet P2Y 12 inhibitory effects with a larger therapeutic window compared to the oral P2Y 12 inhibitors. Such findings make selatogrel a promising agent to be tested in phase 3 studies., Expert Opinion: Advantages of subcutaneous administration of selatogrel are fast onset of action, easy administration and the fecal excretion not requiring dose adjustment based on renal function. These characteristics may translate into an advantage in the peri-procedural setting and in emergency and/or unconscious patients. Selatogrel may represent a viable alternative to intravenous P2Y 12 inhibition (i.e. cangrelor), although some aspects need to be further clarified, including side effects, how to switch to oral P2Y 12 inhibitor and the association with concomitant drugs.

Coronary artery disease remains the major cause of mortality worldwide. Antiplatelet drugs such as acetylsalicylic acid and P2Y12 receptor antagonists are cornerstone treatments for the prevention of thrombotic events in patients with coronary artery disease. Clopidogrel has long been the gold standard but has major pharmacological limitations such as a slow onset and long duration of effect, as well as weak platelet inhibition with high inter-individual pharmacokinetic and pharmacodynamic variability. There has been a strong need to develop potent P2Y12 receptor antagonists with more favorable pharmacological properties. Prasugrel and ticagrelor are more potent and have a faster onset of action; however, they have shown an increased bleeding risk compared with clopidogrel. Cangrelor is highly potent and has a very rapid onset and offset of effect; however, its indication is limited to P2Y12 antagonist-naïve patients undergoing percutaneous coronary intervention. Two novel P2Y12 receptor antagonists are currently in clinical development, namely vicagrel and selatogrel. Vicagrel is an analog of clopidogrel with enhanced and more efficient formation of its active metabolite. Selatogrel is characterized by a rapid onset of action following subcutaneous administration and developed for early treatment of a suspected acute myocardial infarction. This review article describes the clinical pharmacology profile of marketed P2Y12 receptor antagonists and those under development focusing on pharmacokinetic, pharmacodynamic, and drug-drug interaction liability.

The P2Y12 receptor antagonist selatogrel which exhibits rapid inhibition of platelet aggregation following subcutaneous administration is in development for the treatment of acute myocardial infarction.This human ADME study was performed in six healthy male subjects to determine the routes of elimination and to identify/quantify the metabolites of selatogrel at a therapeutically relevant dose of 16 mg [ 14 C]-radiolabelled selatogrel.The median t max and t 1/2 of selatogrel was 0.75 h and 4.7 h, respectively. It was safe and well tolerated based on adverse event, ECG, vital sign and laboratory data.Geometric mean total recovery of [ 14 C]-radioactivity was 94.9% of which 92.5% was recovered in faeces and 2.4% in urine.Selatogrel was the most abundant entity in each matrix. In plasma, no major metabolite was identified. In excreta, the glucuronide M21 (14.7% of radioactivity) and the mono-oxidized A1 (6.2%) were the most abundant metabolites in urine and faeces, respectively.Overall, none of the metabolic pathways contributed to a relevant extent to the overall elimination of selatogrel, i.e. by more than 25% as defined per regulatory guidance. Hence, no pharmacokinetic interaction studies with inhibitors or inducers of drug-metabolizing enzymes are warranted for clinical development of selatogrel.

Objectives: The aim of this study was to develop a risk score integrating cytochrome P450 2C19 loss-of-function genotypes with clinical risk factors influencing clopidogrel response that would allow the identification with more precision of subjects at risk for high platelet reactivity (HPR) and adverse clinical outcomes., Background: Clopidogrel is the most broadly used platelet P2Y 12 inhibitor. However, a considerable number of patients achieve inadequate platelet inhibition, with persistent HPR, an established marker of increased thrombotic risk, underscoring the need for tools to help identify these subjects. Although carriers of loss-of-function alleles of the cytochrome P450 2C19 enzyme have reduced clopidogrel metabolism leading to increased rates of HPR and thrombotic complications, this explains only a fraction of the pharmacodynamic response to clopidogrel, and a number of clinical factors have also been shown to have contributing roles., Methods: Three prospective and independent studies were used to: 1) develop a risk score integrating genetic and clinical factors to identify patients with HPR while on clopidogrel; 2) investigate the external validity of the risk score; and 3) define clinical outcomes associated with the risk score in a cohort of patients with myocardial infarction treated with clopidogrel., Results: A risk score ABCD-GENE (Age, Body Mass Index, Chronic Kidney Disease, Diabetes Mellitus, and Genotyping) was developed incorporating 5 independent predictors of HPR: 4 clinical (age >75 years, body mass index >30 kg/m 2 , chronic kidney disease [glomerular filtration rate <60 ml/min], and diabetes mellitus) and 1 genetic (cytochrome P450 2C19 loss-of-function alleles). The C-statistics for the score as an integer variable were 0.71 (95% confidence interval [CI]: 0.68 to 0.75) and 0.64 (95% CI: 0.60 to 0.67) in the pharmacodynamic derivation and validation cohorts, respectively. A cutoff score ≥10 was associated with the best sensitivity and specificity to identify HPR status. The C-statistics for the score were 0.67 (95% CI: 0.64 to 0.71) for all-cause death and 0.66 (95% CI: 0.63 to 0.69) for the composite of all-cause death, stroke, or myocardial infarction at 1 year. Using multiple models for adjustment, the ABCD-GENE score consistently and independently correlated with all-cause death, as well as with the composite of all-cause death, stroke, or myocardial infarction, both as a continuous variable and by using the cutoff of ≥10. The score did not predict bleeding., Conclusions: The ABCD-GENE score is a simple tool to identify patients with HPR on clopidogrel and who are at increased risk for adverse ischemic events, including mortality, following an acute myocardial infarction. In patients with a high ABCD-GENE score, long-term oral P2Y 12 inhibitors other than clopidogrel should be considered., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Oral anticoagulants and antiplatelet drugs are commonly prescribed to lower the risk of cardiovascular diseases, such as venous and arterial thrombosis, which represent the leading causes of mortality worldwide. A significant percentage of patients taking antithrombotics will nevertheless experience bleeding or recurrent ischemic events, and this represents a major public health issue. Cardiovascular medicine is now questioning the one-size-fits-all policy, and more personalized approaches are increasingly being considered. However, the available tools are currently limited and they are only moderately able to predict clinical events or have a significant impact on clinical outcomes. Predicting concentrations of antithrombotics in blood could be an effective means of personalization as they have been associated with bleeding and recurrent ischemia. Target concentration interventions could take advantage of physiologically based pharmacokinetic (PBPK) and population-based pharmacokinetic (POPPK) models, which are increasingly used in clinical settings and have attracted the interest of governmental regulatory agencies, to propose dosages adapted to specific population characteristics. These models have the benefit of combining parameters from different sources, such as experimental in vitro data and patients' demographic, genetic, and physiological in vivo data, to characterize the dose-concentration relationships of compounds of interest. As such, they can be used to predict individual drug exposure. In the near future, these models could therefore be a valuable means of predicting personalized antithrombotic blood concentrations and, hopefully, of preventing clinical non-response or bleeding in a given patient. Existing approaches for personalization of antithrombotic prescriptions will be reviewed using practical examples for P2Y 12 inhibitors and direct oral anticoagulants. The review will additionally focus on the existing PBPK and POPPK models for these two categories of drugs. Lastly, we address potential scenarios for their implementation in clinics, along with the main limitations and challenges.

Background and Objective: Ticagrelor, a reversible P2Y 12 platelet inhibitor, is under investigation as a sickle cell disease (SCD) therapy in children. HESTIA1 (NCT02214121) was the first ticagrelor study generating pharmacokinetic (PK), pharmacodynamic (PD, P2Y 12 reactivity units [PRU]), and safety data in 45 pediatric SCD patients. Population PK and PK/PD relationships for ticagrelor were quantified using a PK approach., Methods: An adult population PK model was refined to describe ticagrelor and AR-C124910XX (active metabolite) plasma concentration and time data over a wide range of single/repeated ticagrelor doses (0.125-2.25 mg/kg). Population PK/PD modeling was used to describe the time course and extent of platelet inhibition. Demographic covariate relationships were investigated., Results: The final population PK model adequately described ticagrelor and AR-C124910XX plasma concentrations over time. An allometric body weight relationship between ticagrelor and AR-C124910XX clearances and volumes of distribution was used. Significant covariates for ticagrelor were sex (relative bioavailability) and cholecystectomy (central volume of distribution). Estimated oral clearances (35 kg patient; median bodyweight) were 22.8 L/h (ticagrelor) and 9.97 L/h (AR-C124910XX). The final population PK/PD model well-described the time course and extent of platelet inhibition. Estimated baseline PRU was 283, maximum PRU effect was fixed at 1, and the ticagrelor concentration for half-maximum PRU effect was 233 nmol/L., Conclusions: These analyses offer the first quantitative characterization of the dose-exposure-response relationship for ticagrelor in pediatric SCD patients. This model-based approach may be used to inform dose selection and design of subsequent studies that aim to define ticagrelor safety and efficacy in pediatric SCD patients.

Several platelet P2Y 12 inhibiting agents, both oral and intravenous, are available for clinical use. The oral P2Y 12 inhibitors comprise clopidogrel, prasugrel, and ticagrelor. Cangrelor is the only intravenous P2Y 12 inhibitor. Numerous pharmacodynamic studies have been performed to assess the impact of P2Y 12 inhibitor switching on platelet reactivity profiles and to define the optimal strategy if switching is needed, with the goal of minimizing the risk of having inadequate platelet inhibition due to potential drug-drug interactions occurring during the drug overlap phase. This article provides an overview of pharmacodynamic studies assessing switching between P2Y 12 inhibitors and recommendations on switching modalities based on these findings., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Dual-antiplatelet therapy (DAPT) with aspirin and a P2Y 12 receptor inhibitor is the standard treatment for patients undergoing percutaneous coronary intervention. The availability of different P2Y 12 receptor inhibitors (clopidogrel, prasugrel, ticagrelor) with varying levels of potency has enabled physicians to contemplate individualized treatment regimens, which may include escalation or de-escalation of P2Y 12 -inhibiting therapy. Indeed, individualized and alternative DAPT strategies may be chosen according to the clinical setting (stable coronary artery disease vs. acute coronary syndrome), the stage of the disease (early- vs. long-term treatment), and patient risk for ischemic and bleeding complications. A tailored DAPT approach may be potentially guided by platelet function testing (PFT) or genetic testing. Although the routine use of PFT or genetic testing in percutaneous coronary intervention-treated patients is not recommended, recent data have led to an update in guideline recommendations that allow considering selective use of PFT for DAPT de-escalation. However, guidelines do not expand on when to implement the selective use of such assays into decision making for personalized treatment approaches. Therefore, an international expert consensus group of key leaders from North America, Asia, and Europe with expertise in the field of antiplatelet treatment was convened. This document updates 2 prior consensus papers on this topic and summarizes the contemporary updated expert consensus recommendations for the selective use of PFT or genotyping in patients undergoing percutaneous coronary intervention., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Ticagrelor, a P2Y 12 receptor antagonist, has been highly recommended for use in acute coronary syndrome. The major active metabolite (AM) is similar to the parent drug, which exhibits antiplatelet activity. The inhibition of platelet aggregation (IPA) is used as an assay to demonstrate the anticoagulant efficacy of ticagrelor. In this study, we developed a physiologically based pharmacokinetic (PBPK) model to predict the pharmacokinetics of ticagrelor and its AM and combined this model with a pharmacodynamics model to reflect potential pharmacodynamic alterations in liver cirrhosis populations. The simulated results obtained using the PBPK model were validated by fold error values, which were all smaller than 2. Comparisons of exposure in different classifications of liver cirrhosis indicated that exposure to ticagrelor increased significantly with an increase in the degree of cirrhosis severity, whereas exposure to AM was decreased. The total concentration of ticagrelor and AM was related to the IPA included in the Sigmoid E max model. The PBPK model of ticagrelor and AM could predict the pharmacokinetics of all populations, and a combination of PD models was used to extrapolate for predicting unknown scenarios. Liver cirrhosis may result in prolonged IPA, depending on the severity degree of this disease. The combined PBPK model including IPA can reveal changes in pharmacokinetics and pharmacodynamics in populations affected by liver cirrhosis and indicate the risk potential., (Copyright © 2019. Published by Elsevier Inc.)

Background and Objective: Ticagrelor is a P2Y 12 receptor inhibitor approved as an antiplatelet drug for patients with acute coronary syndrome or a history of myocardial infarction. Ticagrelor is also being investigated for the reduction of vaso-occlusive crises in pediatric patients with sickle cell disease. A pediatric formulation suitable for this age range was developed; the development strategy is described. Primary objectives were determining the relative bioavailability of ticagrelor pediatric tablets and granules for oral suspension to the adult immediate-release tablet, and the pediatric tablets taken whole and dispersed/suspended in water to the granules for oral suspension. Bioequivalence between the pediatric tablet taken whole or suspended in water was also assessed. Secondary objectives were comparing the formulations' safety and tolerability., Methods: We conducted a randomized, four-period, cross-over, single-dose study. Pharmacokinetic parameters were assessed for ticagrelor and its active metabolite AR-C124910XX. Bioequivalence was concluded if the 90% confidence intervals of the maximum plasma concentration and area under the plasma concentration-time curve ratios were contained completely within the 80.00-125.00% limits for ticagrelor/AR-C124910XX., Results: Forty-four healthy adults (95% white; 57% male) were included. Similar bioavailability of ticagrelor (and AR-C124910XX) was demonstrated for all comparisons tested. Ticagrelor pediatric tablets taken whole were bioequivalent to pediatric tablets suspended in water. The plasma concentration-time profiles for ticagrelor and AR-C124910XX were similar, showing rapid ticagrelor absorption and AR-C124910XX formation. All formulations were well tolerated., Conclusion: Similar bioavailability of a new pediatric dispersible tablet formulation of ticagrelor for use across a wide age range of pediatric patients was demonstrated compared with other oral ticagrelor formulations. CLINICALTRIALS., Gov Identifier: NCT03126695., Eudract: 2017-000371-93.

Aims: Currently available data indicate that reduction of ticagrelor maintenance dose (MD) 1-3 years after acute myocardial infarction (AMI) not only provides sufficient platelet inhibition but also can improve ticagrelor's safety profile. The aim of this study was to compare the antiplatelet effect of reduced and standard ticagrelor MD in stable patients beginning 1 month after AMI., Methods and Results: In a single-centre, randomized, open-label, active-controlled trial, on Day 30 following AMI, 52 patients (26 in each study arm) were assigned in a 1:1 ratio to receive either reduced (60 mg b.i.d) or standard (90 mg b.i.d) ticagrelor MD for the following 2 weeks. On Day 45 after AMI the antiplatelet effect of ticagrelor was evaluated with the VASP assay and Multiplate, and there were no significant differences in platelet inhibition between patients on reduced vs. standard MD [VASP: 10.4 (5.6-22.2) vs. 14.1 (9.4-22.1) platelet reactivity index; P = 0.30; Multiplate: 30.0 (24.0-39.0) vs. 26.5 (22.0-35.0) U; P = 0.26]. Likewise, no differences were found regarding the prevalence of on-ticagrelor high platelet reactivity between patients on ticagrelor 60 mg b.i.d vs. 90 mg b.i.d (VASP: 4% vs. 8%; P = 0.67; Multiplate: 15% vs. 8%; P = 0.54). Administration of reduced MD resulted in proportionally lower plasma concentrations of ticagrelor and its active metabolite on Day 45 after AMI., Conclusion: These results suggest that lowering ticagrelor MD 1 month after AMI confers an adequate antiplatelet effect that is comparable to the standard dose. The tested strategy warrants further research to assess its clinical efficacy and safety., Clinicaltrials.gov Identifier: NCT03251859., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Aims: Recent evidence demonstrates that intravenous morphine significantly reduces absorption and delays onset of action of oral P2Y12 receptor inhibitors in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI). We aimed to assess the influence of intravenous fentanyl compared with morphine on pharmacokinetics and pharmacodynamics of ticagrelor and its active metabolite (AR-C124910XX) in patients undergoing pPCI for STEMI., Methods and Results: Single-centre, prospective, open-label, randomized controlled study that will randomly assign in a 1:1 ratio patients with STEMI undergoing pPCI to receive intravenous fentanyl or morphine following a pre-hospital 180-mg loading dose of ticagrelor (ClinicalTrials.gov Identifier: NCT02531165). Pharmacokinetic and pharmacodynamic analyses will be performed at baseline and 1, 2, 4, 6, and 12 h post-loading dose. Pharmacodynamic assessments will include P2Y12 reaction units (PRU) measured by VerifyNow P2Y12. Pharmacokinetic assessments include determination of maximal observed plasma concentrations, time for maximal plasma concentration, and area under the plasma concentration vs. time curve from time 0 to the last measurable concentration (AUC0-t) for ticagrelor and AR-C124910XX. The primary endpoint is platelet reactivity assessed by PRU at 2 h post ticagrelor loading dose., Conclusion: PERSEUS will provide randomized data regarding the impact of fentanyl administration, in patients with STEMI undergoing pPCI, on platelet inhibition and ticagrelor absorption and total exposure., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.)

Current guidelines recommend dual antiplatelet therapy-a P2Y 12 inhibitor (clopidogrel, prasugrel, or ticagrelor) and aspirin-for patients undergoing percutaneous coronary intervention. Although clopidogrel is the most commonly prescribed P2Y 12 inhibitor, it is associated with an increased risk of major adverse cardiovascular events in patients carrying loss-of-function CYP2C19 alleles. In contrast, CYP2C19 genotype does not impact clinical response to prasugrel or ticagrelor. Nevertheless, routine implementation of CYP2C19 genotyping to guide antiplatelet therapy selection has remained controversial because of the lack of large randomized controlled trials evaluating this strategy. Emerging results from registry studies and small clinical trials of CYP2C19 genotype-guided antiplatelet therapy following percutaneous coronary intervention offer new insight and contribute to a growing evidence base that supports the clinical utility of a genotyping strategy to personalize antiplatelet therapy selection.

Common genetic variation in CYP2C19 (cytochrome P450, family 2, subfamily C, polypeptide 19) *2 and *3 alleles leads to a loss of functional protein, and carriers of these loss-of-function alleles when treated with clopidogrel have significantly reduced clopidogrel active metabolite levels and high on-treatment platelet reactivity resulting in increased risk of major adverse cardiovascular events, especially after percutaneous coronary intervention. The Food and Drug Administration has issued a black box warning advising practitioners to consider alternative treatment in CYP2C19 poor metabolizers who might receive clopidogrel and to identify such patients by genotyping. However, routine clinical use of genotyping for CYP2C19 loss-of-function alleles in patients undergoing percutaneous coronary intervention is not recommended by clinical guidelines because of lack of prospective evidence. To address this critical gap, TAILOR-PCI (Tailored Antiplatelet Initiation to Lessen Outcomes due to Decreased Clopidogrel Response After Percutaneous Coronary Intervention) is a large, pragmatic, randomized trial comparing point-of-care genotype-guided antiplatelet therapy with routine care to determine whether identifying CYP2C19 loss-of-function allele patients prospectively and prescribing alternative antiplatelet therapy is beneficial.

Platelet P2Y 12 receptors play a key role in platelet activation and thrombus formation. Accordingly, P2Y 12 receptor antagonists are the cornerstone of secondary prevention of atherothrombotic events in patients undergoing percutaneous coronary intervention (PCI). The availability of different oral P2Y 12 antagonists (clopidogrel, prasugrel, ticagrelor) along with the introduction of the first intravenous P2Y 12 antagonist cangrelor offer an opportunity to individualize antiplatelet therapy according to the changing clinical setting. The recent International Expert Consensus provided the first recommendations on switching between the P2Y 12 antagonists. While the consensus greatly helps to guide switching between P2Y 12 antagonists, a number of controversial clinical scenarios remain where the evidence regarding the optimal switch strategy is scarce. In such clinical scenarios, understanding of the (i) pharmacological properties of P2Y 12 antagonists, (ii) recent evidence from pharmacodynamics studies, clinical trials and registries, and (iii) factors affecting the efficacy and safety of the P2Y 12 antagonists, all summarized below, are crucial to choose the optimal switch strategy., (Copyright © 2019 Elsevier Inc. All rights reserved.)

P2Y 12 antagonists are widely used as antiplatelet agents for the prevention and treatment of arterial thrombosis. Based on the scaffold of a known P2Y 12 antagonist AZD1283, a series of novel bicyclic pyridine derivatives were designed and synthesized. The cyclization of the ester substituent on the pyridine ring to the ortho-methyl group led to lactone analogues of AZD1283 that showed significantly enhanced metabolic stability in subsequent structure-pharmacokinetic relationship studies. The metabolic stability was further enhanced by adding a 4-methyl substituent to the piperidinyl moiety. Compound 58l displayed potent inhibition of platelet aggregation in vitro as well as antithrombotic efficacy in a rat ferric chloride model. Moreover, 58l showed a safety profile that was superior to what was observed for clopidogrel in a rat tail-bleeding model. These results support the further evaluation of compound 58l as a promising drug candidate.

The aim of this study is to improve the bioavailability of ticagrelor, BCS class 4 drug, using solid dispersion technique, and to evaluate the potential of ticagrelor loaded-solid dispersion, as a new formulation. The solid dispersion formulation was prepared via solvent evaporation method using ethanol. TPGS and Neusilin® US2 selected via screening studies were used for preparing formulation. The results of scanning electron microscopy, differential scanning calorimetry and powder X-ray diffraction showed that the crystallinity of the ticagrelor was completely transformed to an amorphous form and maintained in the solid dispersion formulation. The released amount of the optimized solid dispersion significantly increased by 2.2- and 34-fold in comparison with physical mixture (Ticagrelor:TPGS:Neusilin® US2 = 1:2:2, w/w/w) and commercial product (Brilinta®) in distilled water at 90 min, respectively. The absorptive permeability was improved (1.4-fold) and the efflux ratio was decreased (0.45-fold) by formulation containing TPGS acting as a P-gp inhibitor compared to pure drug. The solid dispersion formulation improved the peak plasma concentration (C max ) and relative bioavailability compared to that of pure drug as 238.09 ± 25.96% and 219.78 ± 36.33%, respectively, after oral administration in rats. Thus, we successfully prepared the solid dispersion formulation for enhancing oral bioavailability of ticagrelor, and then this formulation would be recommended as a practical oral pharmaceutical product., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Various antiplatelet drugs are used following Acute Coronary Syndromes (ACS). Of them, adenosine diphosphate receptor P2Y12 inhibitors clopidogrel, prasugrel and ticagrelor are currently used for post-ACS long-term treatment. Although they act on the same receptor, they differ in pharmacodynamics and pharmacokinetics. Several enzymes and transporters involved in the metabolism of P2Y12 inhibitors show genetic variability with functional impact. This includes Pglycoprotein, carboxylesterase 1 and, most notably, CYP2C19 that is important in clopidogrel activation. Common gain-of-function or loss-of-function alleles of CYP2C19 gene are associated with lower or higher platelet reactivity that may impact clinical outcomes of clopidogrel treatment. Prasugrel is considered to be less dependent on CYP2C19 variability as it is also metabolized by other CYP450 isoforms. Some studies, however, showed the relevance of CYP2C19 variants for platelet reactivity during prasugrel treatment as well. Ticagrelor is metabolized mainly by CYP3A4, which does not show functionally relevant genetic variability. Its concentrations may be modified by the variants of Pglycoprotein gene ABCB1. While no substantial difference between the clinical efficacy of prasugrel and ticagrelor has been documented, both of them have been shown to be superior to clopidogrel in post-ACS treatment. This can be partially explained by lower variability at each step of their metabolism. It is probable that factors influencing the pharmacokinetics of both drugs, including genetic factors, may predict the clinical efficacy of antiplatelet treatment in personalized medicine., Conclusion: We summarize the pharmacokinetics and pharmacogenetics of P2Y12 inhibitors with respect to their clinical effects in post-myocardial infarction treatment., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

ACT-246475 is a selective and reversible P2Y 12 receptor antagonist inducing inhibition of platelet aggregation (IPA). A randomized, double-blind, placebo-controlled, parallel-design study was performed to investigate the safety, tolerability, pharmacokinetics, and pharmacodynamics of escalating single subcutaneous doses of ACT-246475 (1, 2, 4, 8, 16, or 32 mg) in healthy male subjects (N = 8 per dose, 3:1 active:placebo ratio). Pharmacodynamic effects were assessed based on maximum platelet aggregation and P2Y 12 reaction units using light transmission aggregometry and VerifyNow ® assays, respectively. ACT-246475 was safe and well tolerated up to 32 mg based on adverse event data and absence of clinically relevant changes in hematology, biochemistry, vital signs, and electrocardiogram variables. Median time to reach maximum plasma concentration was 0.5-0.75 hours, and geometric mean terminal half-life ranged from 1.3 to 9.2 hours across the tested dose range. Exposure to ACT-246475 was dose proportional across all dose groups. The maximal %IPA was reached within 30 minutes after subcutaneous administration of ACT-246475. A dose-dependent duration and extent of effect were observed based on area under the effect curve and maximum effect data. Similar results were observed for maximum platelet aggregation and P2Y 12 reaction units. The %IPA was ≥85% at doses ≥2 mg. This level of %IPA was extended to at least 12 hours in the 32-mg dose group. The safety and pharmacokinetic/pharmacokinetic profile with quick onset and adequate duration of IPA support further investigation in patients with coronary artery disease., (© 2018, The American College of Clinical Pharmacology.)

Extensive search for methods of overcoming morphine-related delay of the absorption and onset of action of oral P2Y 12 inhibitors in patients presenting with acute coronary syndrome is on-going. The aim of the trial was to investigate whether metoclopramide co-administration could reduce this delay and improve the pharmacokinetics (PKs) and pharmacodynamics (PDs) of ticagrelor and its active metabolite AR-C124900XX. Plasma concentration of both compounds and platelet reactivity were evaluated in nine pre-defined time points within 6 hours after administration of ticagrelor loading dose. The results of our study show that mean platelet activity within the first hour was noticeably higher in metoclopramide-naive patients. Moreover, ticagrelor mean plasma concentration was significantly higher within the initial four time points (15, 30, 45, 60 minutes) in patients receiving metoclopramide ( p  = 0.039; p  = 0.009; p  = 0.005; p  = 0.008, respectively). To conclude, the co-administration of metoclopramide in patients presenting with unstable angina and treated with morphine, has a beneficial effect on the PK/PD profile of ticagrelor and its metabolite; however, its impact on ST-elevation myocardial infarction patients requires further investigation., Competing Interests: J.M. Siller-Matula has received grants and consultancy fees from AstraZeneca, Eli Lilly, Daiichi Sankayo, Bayer and Roche. E.P.N received honoraria from Astra Zeneca, Sanofi-Regeneron, Eli-Lilly and grants from Amgen. J. Kubica has received a consulting fee from AstraZeneca. None of the other authors declares any conflict of interest., (Georg Thieme Verlag KG Stuttgart · New York.)

Because of its high prevalence, chronic kidney disease (CKD) remains a major health hazard throughout the world. Patients with CKD have a high prevalence and incidence of acute coronary syndromes (ACS). Despite decades of improved care, their higher risk profile persists and cardiovascular diseases remain their leading cause of death. Along with the reduction of glomerular filtration rate, several physiological processes are impacted and participate in the pathophysiology of ischemic and bleeding events. CKD is associated with an accelerated and severe course of atherothrombotic disease, and this relates to a modified vascular milieu with alterations on the level of the coagulation cascade and platelet aggregation. In addition, pharmacokinetics of several drugs, in particular antithrombotics, are altered and differ from that of non-CKD patients. Patients with CKD therefore represent a challenging population for both physicians and researchers. In addition to these perturbations of physiological processes, CKD patients face 2 major issues. First, there is a clear gap in scientific research as they are commonly underrepresented or excluded from major clinical trials. This is particularly true regarding antithrombotic treatment during ACS. Second, there is a gap in offering evidence-based treatment for these patients including state-of-the art options for revascularization and modern antiplatelet treatment, both of which are commonly underused. During the last decade, new potent oral P2Y 12 -ADP receptor antagonists, prasugrel and ticagrelor, which are more potent antiplatelet agents compared with clopidogrel, were introduced for ACS treatment. However, despite the fact that CKD patients represent a large proportion of those experiencing an ACS and are considered at high risk, there is a lack of dedicated trials and we are left with subgroup analysis of large randomized clinical trials were stage 4 and dialysis patients were rare. In the present review we summarize the mechanisms involved in the high ischemic and bleeding risk of CKD patients and the risk-benefit ratio of potent antiplatelet drugs during ACS.

Background and Objectives: Prasugrel and clopidogrel are inhibitors of the ADP-P 2 Y 12 platelet receptor used in acute coronary syndrome patients. They require bioactivation via isoenzymes such as cytochrome P450 (CYP) 3A4, CYP2C19 and CYP2B6. Ritonavir and cobicistat are potent CYP3A inhibitors, prescribed as pharmacokinetic (PK) enhancers in the treatment of human immunodeficiency virus (HIV) infection., Methods: In this study, the impact of boosted antiretroviral therapies (ARTs) on the PK of clopidogrel and prasugrel active metabolites (AMs), and on the efficacy of prasugrel and clopidogrel, were evaluated in a randomized crossover clinical trial., Results: A significantly lower exposure to clopidogrel AM [3.2-fold lower area under the concentration-time curve (AUC) and maximum plasma concentration (C max )] and prasugrel AM (2.1-fold and 1.7-fold lower AUC and C max ) were demonstrated in HIV-infected patients treated with boosted ARTs compared with healthy controls; however, a differential impact was observed on platelet inhibition between clopidogrel and prasugrel. Clopidogrel 300 mg induced adequate (although modest) platelet inhibition in all healthy subjects, while platelet inhibition was insufficient in 44% of HIV patients. On the contrary, prasugrel 60 mg induced a potent platelet inhibition in both healthy and HIV-infected subjects., Conclusion: Prasugrel appears to remain an adequate antiplatelet agent in HIV-infected patients and could be preferred to clopidogrel in this context, regardless of the metabolic interaction and inhibition of its bioactivation pathways.

Purpose: This single-dose, randomized, open-label, parallel-group, and crossover study assessed pharmacokinetics (PK), pharmacodynamics (PD), and safety of ticagrelor in subjects on hemodialysis versus healthy subjects., Methods: Hemodialysis subjects were randomized, receiving a single ticagrelor 90-mg dose 1 day post-hemodialysis or just before hemodialysis, with an intervening washout of ≥ 7 days. Healthy subjects (creatinine clearance ≥ 90 mL/min) received a single ticagrelor 90-mg dose. PK, PD (P2Y 12 reaction units [PRU], inhibition of platelet aggregation [IPA]), and safety were evaluated., Results: Twenty-seven subjects (14 hemodialysis, 13 healthy) received ticagrelor. The mean maximum plasma concentration (C max ) and area under the plasma concentration curve from time zero to infinity (AUC 0-∞ ) of ticagrelor were 598.4 ng/mL and 3256.1 ng·h/mL, respectively, in pre-hemodialysis subjects; 560.3 ng/mL and 3015.1 ng·h/mL, respectively, in post-hemodialysis subjects; and 370.8 ng/mL and 2188.8 ng·h/mL, respectively, in healthy subjects. C max and AUC 0-∞ of AR-C124910XX, the active metabolite, were 152.3 ng/mL and 1144.2 ng·h/mL, respectively, in pre-hemodialysis subjects; 130.8 ng/mL and 1127.8 ng·h/mL, respectively, in post-hemodialysis subjects; and 111.7 ng/mL and 1000.4 ng·h/mL, respectively, in healthy subjects. Mean IPA time curves over 24 h post-dose were almost indistinguishable for all three treatments. The greatest reduction in mean PRU occurred approximately 2 h post-dose for all three treatments. No safety or tolerability issues were identified., Conclusion: Hemodialysis resulted in modestly higher exposure to ticagrelor and AR-C124910XX, with no clinically significant effect on PD or tolerability. Accordingly, no dose adjustment is required for hemodialysis patients. Timing of hemodialysis has little impact on ticagrelor PK, or the effect of ticagrelor on IPA.

Morphine delays oral P2Y 12 platelet inhibitor absorption and is associated with adverse outcomes after myocardial infarction. Consequently, many physicians and first responders are now considering fentanyl as an alternative. We conducted a single-centre trial randomizing cardiac patients undergoing coronary angiography to intravenous fentanyl or not. All participants received local anaesthetic and intravenous midazolam. Those requiring percutaneous coronary intervention (PCI) with stenting received 180 mg oral ticagrelor intra-procedurally. The primary outcome was area under the ticagrelor plasma concentration-time curve (AUC 0-24 hours ). The secondary outcomes were platelet function assessed at 2 hours after loading, measured by P2Y 12 reaction units (PRUs) and light transmission platelet aggregometry. Troponin-I was measured post-PCI using a high-sensitivity troponin-I assay (hs-TnI). All participants completed a survey of pain and anxiety. Of the 212 randomized, 70 patients required coronary stenting and were loaded with ticagrelor. Two participants in the no-fentanyl arm crossed over to receive fentanyl for pain. In as-treated analyses, ticagrelor concentrations were higher in the no-fentanyl arm (AUC 0-24 hours 70% larger, p  = 0.03). Platelets were more inhibited by 2 hours in the no-fentanyl arm (71 vs. 113 by PRU, p  = 0.03, and 25% vs. 41% for adenosine diphosphate response by platelet aggregation, p  < 0.01). Mean hs-TnI was higher with fentanyl at 2 hours post-PCI (11.9 vs. 7.0 ng/L, p  = 0.04) with a rate of enzymatic myocardial infarction of 11% for fentanyl and 0% for no-fentanyl ( p  = 0.08). No statistical differences in self-reported pain or anxiety were found. In conclusion, fentanyl administration can impair ticagrelor absorption and delay platelet inhibition, resulting in mild excess of myocardial damage. This newly described drug interaction should be recognized by physicians and suggests that the interaction between opioids and oral P2Y 12 platelet inhibitors is a drug class effect associated with all opioids., Clinical Trial Registration:  https://clinicaltrials.gov/ct2/show/NCT02683707 (: NCT02683707)., Competing Interests: None., (Georg Thieme Verlag KG Stuttgart · New York.)

Objectives: The manuscript was mainly aimed to evaluate effects of food and gender on the pharmacokinetics of ticagrelor and its main active metabolite AR-C124910XX in healthy Chinese subjects observed in the bioequivalence studies of the two formulations of ticagrelor tablets., Materials and Methods: The single-dose, two-sequence, two-period and crossover studies were respectively conducted under fasting and fed conditions. Plasma samples were analyzed by an HPLC-MS/MS method. Log-transformed pharmacokinetic parameters of ticagrelor and AR-C124910XX obtained from the trials were compared by the mean of two one-sided t-test., Results: Pharmacokinetic parameters of the two formulations were evaluated. The mean ticagrelor tmax value was delayed by 0.28 - 0.53 hours owing to meals. A 21.6 - 24.0% (p < 0.05) increase in the mean ticagrelor AUC* (body weight-normalized AUC) value was measured (fed vs. fasting). For AR-C124910XX, the mean T1/2 value was delayed by 0.84 - 1.33 hours (p < 0.05) due to meals. A 52.0 - 55.8% (p < 0.05) decrease in the mean Cmax* (body weight-normalized Cmax) value and a 15.6 - 16.9% (p < 0.05) decrease in the mean AUC* value were observed (fed vs. fasting). The female subjects exhibited higher exposures to ticagrelor and AR-C124910XX than the male subjects. Compared with other populations, the Chinese subjects in this study experienced a greater decrease in Cmax of AR-C124910XX due to meals. 21 adverse events of mild intensity occurred over the study periods., Conclusion: The studies showed food effects on the absorption of ticagrelor and the formation of AR-C124910XX, and gender effects on exposures to the drug after single oral-dose administration.
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Background: Ticagrelor, the first reversible P2Y 12 receptor antagonist, exhibits faster onset and offset of antiplatelet effects and more consistent platelet inhibition than clopidogrel in both healthy subjects and patients with stable coronary artery disease., Objective: The objectives of this study were to establish a population pharmacokinetics (PK) and pharmacodynamics (PD) model of ticagrelor and to provide a theoretical basis for the optimization of ticagrelor treatment in clinic., Methods: A single oral dose of 180 mg ticagrelor was administered to 14 healthy male subjects in a randomized study. Common single-nucleotide polymorphisms (SNPs) in biotransformation enzymes CYP3A4 and CYP3A5 (CYP3A4*1G and CYP3A5*3) were genotyped by PCR-direct sequencing. Blood samples were collected to measure plasma concentrations of ticagrelor and its active metabolite AR-C124910XX and maximal platelet inhibition. Various models were evaluated to characterize the pharmacokinetics of ticagrelor and AR-C124910XX as well as their PK-PD relationship. Covariates that may potentially affect PK or PD of ticagrelor and AR-C124910XX were included and assessed. Simulation for dosage regimen was performed based on the final PK-PD model., Results: Ticagrelor and AR-C124910XX PK were best described by a two-compartment model with first-order transit absorption model. CYP3A4*1G increased clearance for AR-C124910XX, but had no significant effect on ticagrelor clearance. The relationship between concentration and platelet response of ticagrelor was best described by a turnover model. Simulation results indicated that a lower dosage regimen of 30 mg maintenance dose (MD) could produce an anticipated anti-platelet response in comparison to the routine clinical dosage regimen (180 mg loading dose (LD), 90 mg MD)., Conclusion: Our study developed a population PK-PD model for ticagrelor and further simulation for dosage regimen was performed based on the final model. Compared to the current recommended dosage regimen (180 mg LD, 90 mg MD), our simulation result of a relatively lower dose (30 mg MD) could also obtain an acceptable anti-platelet response, which may provide a reference for further dosage regimen design in Chinese population.

Introduction: Cardiovascular disease (CVD) is the main cause of death in the world. Coronary artery disease (CAD) is the most common form of CVD presentation, but the prevalence of peripheral artery disease (PAD) is increasing. Patients with polyvascular disease comprise a very high-risk population that has been infrequently studied. Areas covered: The authors review the current evidence of the efficacy and safety of ticagrelor in the setting of acute coronary syndrome and stable patients post-MI with and without PAD and summarize its pharmacokinetics, pharmacodynamics, and regulatory issues. Expert opinion: Randomized studies showed that ticagrelor is superior to clopidogrel in patients with acute coronary syndromes, and is superior to placebo in the chronic phase (>1 year) post-myocardial infarction. Sub-analyses of these studies suggest that patients with myocardial infarction and PAD, compared to patients without these characteristics, may have greater benefit with ticagrelor. Nonetheless, the global evidence about the role of ticagrelor in patients with myocardial infarction and PAD remains relatively sparse, and a prospective randomized trial testing this hypothesis would be necessary to provide more definite data regarding the efficacy and safety of ticagrelor in this very high-risk population.