Clinical and Pre-Clinical Pharmacokinetics and Pharmacodynamics of Bentracimab.

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 P2Y12 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.

Influence of body weight and body mass index on the chronic pharmacokinetic and pharmacodynamic responses to clinically available doses of ticagrelor in patients with chronic coronary syndromes.

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/m2) 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 P2Y12 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.

Ticagrelor.

Ticagrelor is one of the most recent antiplatelet agents used to inhibit platelet aggregation via blocking the ADP receptors of the subtype P2Y12. 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.

Clopidogrel-herb Interactions: A Pharmacokinetic and Pharmacodynamic Assessment in a Rat Model.

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.

Pharmacokinetic/pharmacodynamic modeling of drug interactions at the P2Y12 receptor between selatogrel and oral P2Y12 antagonists.

Selatogrel is a potent and reversible P2Y12 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 P2Y12 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 P2Y12 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 P2Y12 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 P2Y12 receptor antagonist developed for subcutaneous self-administration by patients in case of suspected acute myocardial infarction. Transition to oral P2Y12 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 P2Y12 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.

Use of the VerifyNow point of care assay to assess the pharmacodynamic effects of loading and maintenance dose regimens of prasugrel and ticagrelor.

Prasugrel and ticagrelor are potent oral platelet P2Y12 inhibitors and are recommended over clopidogrel in patients with acute coronary syndrome (ACS). Oral platelet P2Y12 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 P2Y12 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.

The opioid-P2Y12 inhibitor interaction: Potential strategies to mitigate the interaction and consideration of alternative analgesic agents in myocardial infarction.

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 P2Y12 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-P2Y12 inhibitor interaction, strategies aimed at mitigating the interaction and appraises promising alternative agents to opioid therapy in patients with myocardial infarction.

Pharmacokinetics, mass balance, and metabolism of [14C]vicagrel, a novel irreversible P2Y12 inhibitor in humans.

Vicagrel, a novel irreversible P2Y12 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 [14C]vicagrel (120 µCi). Vicagrel absorption was fast (Tmax = 0.625 h), and the mean t1/2 of vicagrel-related components was ~38.0 h in both plasma and blood. The blood-to-plasma radioactivity AUCinf 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 AUC0-8 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.

Nucleotide P2Y1 receptor agonists are in vitro and in vivo prodrugs of A1/A3 adenosine receptor agonists: implications for roles of P2Y1 and A1/A3 receptors in physiology and pathology.

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 P2Y1 receptor (P2Y1R) 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 A3 and A1ARs. 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 P2Y1R 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.

Predicting the effect of tea polyphenols on ticagrelor by incorporating transporter-enzyme interplay mechanism.

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 IC50 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.

Emerging Role of Fentanyl in Antiplatelet Therapy.

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.

Selatogrel, a novel P2Y12 inhibitor: a review of the pharmacology and clinical development.

INTRODUCTION: Platelet P2Y12 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 P2Y12 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 P2Y12 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 P2Y12 inhibitory effects with a larger therapeutic window compared to the oral P2Y12 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 P2Y12 inhibition (i.e. cangrelor), although some aspects need to be further clarified, including side effects, how to switch to oral P2Y12 inhibitor and the association with concomitant drugs.

Effect of Rifampin-Mediated OATP1B1 and OATP1B3 Transporter Inhibition on the Pharmacokinetics of the P2Y12 Receptor Antagonist Selatogrel.

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 (Cmax ) and area under the concentration curve from zero to infinity (AUC0-∞ ) ratios and for time of maximum plasma concentration (Tmax ) by Wilcoxon signed rank test. In addition, the safety and tolerability of the study treatments were evaluated. The geometric mean ratios of Cmax and AUC0-∞ 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 (t½ ) or Tmax 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.

Derivation, Validation, and Prognostic Utility of a Prediction Rule for Nonresponse to Clopidogrel: The ABCD-GENE Score.

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 P2Y12 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/m2, 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 P2Y12 inhibitors other than clopidogrel should be considered.

Pharmacokinetics and Pharmacodynamics of Approved and Investigational P2Y12 Receptor Antagonists.

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.

Impact of Preadmission Morphine on Reinfarction in Patients With ST-Elevation Myocardial Infarction Treated With Percutaneous Coronary Intervention: A Meta-Analysis.

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 P2Y12 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 P2Y12 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.

Absorption, distribution, metabolism and excretion of the P2Y12 receptor antagonist selatogrel after subcutaneous administration in healthy subjects.

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 [14C]-radiolabelled selatogrel.The median tmax and t1/2 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 [14C]-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.

Pharmacodynamics During Transition Between Platelet P2Y12 Inhibiting Therapies.

Several platelet P2Y12 inhibiting agents, both oral and intravenous, are available for clinical use. The oral P2Y12 inhibitors comprise clopidogrel, prasugrel, and ticagrelor. Cangrelor is the only intravenous P2Y12 inhibitor. Numerous pharmacodynamic studies have been performed to assess the impact of P2Y12 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 P2Y12 inhibitors and recommendations on switching modalities based on these findings.