Publications by authors named "Michael Fossler"

Background: Oliceridine is a G protein-biased µ-opioid, a drug class that is associated with less respiratory depression than nonbiased opioids, such as morphine. The authors quantified the respiratory effects of oliceridine and morphine in elderly volunteers. The authors hypothesized that these opioids differ in their pharmacodynamic behavior, measured as effect on ventilation at an extrapolated end-tidal Pco2 at 55 mmHg, V̇E55.

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COVID-19 causes significant thrombosis and coagulopathy, with elevated D-dimer a predictor of adverse outcome. The precise mechanism of this coagulopathy remains unclear; one hypothesis is that loss of angiotensin-converting enzyme 2 activity during viral endocytosis leads to pro-inflammatory angiotensin-II accumulation, loss of angiotensin-1-7 and subsequent vascular endothelial activation. We undertook a double-blind randomized, placebo-controlled experimental medicine study to assess the effect of TRV027, a synthetic angiotensin-1-7 analogue on D-dimer in 30 patients admitted to hospital with COVID-19.

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Background: Oliceridine, a new class of μ-opioid receptor agonist, may be associated with fewer opioid-related adverse events (ORAEs) due to its unique mechanism of action. Thus, it may provide a cost-effective alternative to conventional opioids such as morphine.

Patients And Methods: Using a decision tree with a 24-hour time horizon, we calculated costs for medication and management of the three most common AEs (oxygen saturation <90%, vomiting, somnolence) following postoperative oliceridine or morphine in high-risk patients.

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Background: Oliceridine is a biased ligand at the μ-opioid receptor recently approved for the treatment of acute pain. In a thorough QT study, corrected QT (QTc) prolongation displayed peaks at 2.5 and 60 minutes after a supratherapeutic dose.

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TRV734, an oral G-protein biased ligand at the μ-opioid receptor has demonstrated differentiated pharmacology in preclinical studies compared to unbiased ligands. First-time-in-human data suggested that TRV734 was safe and well tolerated and caused effective pain relief after single doses of 150 to 250 mg. In this study, safety and tolerability of multiple ascending doses of TRV734, and single doses of TRV734 125 mg following various administration paradigms, in healthy subjects were evaluated.

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Introduction: In the management of postoperative acute moderate-to-severe pain, opioids remain an important component. However, conventional opioids have a narrow therapeutic index and are associated with dose-limiting opioid-related adverse events (ORAEs) that can result in worse patient outcomes. Oliceridine, a new intravenous µ-opioid receptor agonist, is shown in nonclinical studies to be biased for G protein signaling (achieving analgesia) with limited recruitment of β-arrestin (associated with ORAEs).

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Oliceridine, a new class of μ-opioid receptor agonist, is selective for G-protein signaling (analgesia) with limited recruitment of β-arrestin (associated with adverse outcomes) and may provide a cost-effective alternative versus conventional opioid morphine for postoperative pain. Using a decision tree with a 24-h time horizon, we calculated costs for medication and management of three most common adverse events (AEs; oxygen saturation <90%, vomiting and somnolence) following postoperative oliceridine or morphine use. Using oliceridine, the cost for managing AEs was US$528,424 versus $852,429 for morphine, with a net cost savings of $324,005.

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Introduction: Use of parenteral opioids is a major risk factor for postoperative nausea and vomiting. Conventional opioids bind to µ-opioid receptors (MOR), stimulate both the G-protein signaling (achieving analgesia); and the β-arrestin pathway (associated with opioid-related adverse effects). Oliceridine, a next-generation IV opioid, is a G-protein selective MOR agonist, with limited recruitment of β-arrestin.

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Background: To improve understanding of the respiratory behavior of oliceridine, a μ-opioid receptor agonist that selectively engages the G-protein-coupled signaling pathway with reduced activation of the β-arrestin pathway, the authors compared its utility function with that of morphine. It was hypothesized that at equianalgesia, oliceridine will produce less respiratory depression than morphine and that this is reflected in a superior utility.

Methods: Data from a previous trial that compared the respiratory and analgesic effects of oliceridine and morphine in healthy male volunteers (n = 30) were reanalyzed.

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Background: The delta opioid receptor (DOR) has been identified as a therapeutic target for migraine, with DOR agonists exhibiting low abuse potential compared with conventional µ-opioid agonists. TRV250 is a novel small molecule agonist of the DOR that is preferentially selective for G-protein signaling, with relatively little activation of the β-arrestin2 post-receptor signaling pathway. This selectivity provides reduced susceptibility to proconvulsant activity seen with non-selective DOR agonists.

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Background And Objective: Opioid-induced respiratory depression (OIRD) is a potentially fatal complication associated with conventional opioids. Currently, there is a paucity of validated endpoints available to measure respiratory safety. Oliceridine, an investigational intravenous (IV) opioid, is a G-protein selective μ-agonist with limited activity on β-arrestin2, a signaling pathway associated with adverse events including OIRD.

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Novel small molecule inhibitors of the oxytocin receptor (OTR) may have distinct pharmacology and mode of action when compared with first-generation oxytocin antagonists when used for the prevention of preterm birth. The aim was to determine the mechanism of action of small molecule OTR antagonists retosiban and epelsiban compared with the currently used peptide-based compound atosiban. Human myometrial samples were obtained at cesarean section and subjected to pharmacological manipulations to establish the effect of antagonist binding to OTR on downstream signaling.

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Oliceridine is a G protein-biased ligand at the μ-opioid receptor in development for treatment of moderate to severe acute pain. A phase 1, open-label, single-dose study investigated the pharmacokinetics and safety of oliceridine 0.5 mg intravenous (IV) in subjects with end-stage renal disease (ESRD, n = 9) versus 1 mg in healthy controls (n = 8).

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Adherence is important for the effectiveness of human immunodeficiency virus (HIV) preexposure prophylaxis (PrEP). The objective of the current work is to assess the impact of multiple demographic and socio-behavioral factors on the adherence to tenofovir-based PrEP among HIV serodiscordant couples in East Africa using Markov mixed-effects modeling approach. The Partners Demonstration Project was a prospective, open-label, implementation science-driven study of HIV PrEP among heterosexual HIV serodiscordant couples in Kenya and Uganda.

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TRV734 is an orally bioavailable G-protein-biased ligand at the μ-opioid receptor. In nonclinical studies it was potently analgesic while causing less gastrointestinal dysfunction than morphine, suggesting unique benefits in acute pain management. A 2-part, first-in-human study was conducted with ascending doses of TRV734 to explore its tolerability, pharmacokinetics, and pharmacodynamics in healthy volunteers.

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GPR109A (HM74A), a G-protein-coupled receptor, is hypothesized to mediate lipid and lipoprotein changes and dermal flushing associated with niacin administration. GSK256073 (8-chloro-3-pentyl-1H-purine-2,6[3H,7H]-dione) is a selective GPR109A agonist shown to suppress fatty acid levels and produce mild flushing in short-term clinical studies. This study evaluated the effects of GSK256073 on lipids in subjects with low high-density lipoprotein cholesterol (HDLc).

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The Partners Demonstration Project was a prospective, open-label, implementation science-driven study of preexposure prophylaxis (PrEP) among heterosexual HIV serodiscordant couples in Kenya and Uganda. Adherence data were collected using the Medication Event Monitoring System (MEMS), and time of sexual activity was collected using the mobile phone short message service (SMS). Two plasma samples were collected at a single study visit.

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The objective of the study was to develop a population pharmacokinetic model of pemetrexed and identify factors contributing to variability in exposure in Indian patients. Plasma samples were obtained from a cohort of 85 patients following 500 mg/m intravenous infusion and population pharmacokinetic analysis was performed using NONMEM (version 7.3.

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The objective of our study was to evaluate the effect of adherence patterns on the sample size and power of a clinical trial. Simulations from a population pharmacokinetic/pharmacodynamic (PK/PD) model linked to an adherence model were used. Four types of drug characteristics, such as long (~35 hours) and short (~12 hours) half-life in combination with earlier or delayed time to reach steady-state PD end points were studied.

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Background: Despite being in clinical use for about 6 decades, vancomycin dosing remains perplexing and complex.

Methods: A population pharmacokinetic modeling and simulation approach was used to evaluate the efficiency of the current nomogram-based dosing of vancomycin. Serum vancomycin concentrations were obtained as a part of routine therapeutic drug monitoring from two 500-bed academic medical centers.

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Conventional opioids bind to μ-opioid receptors and activate 2 downstream signaling pathways: G-protein coupling, linked to analgesia, and β-arrestin recruitment, linked to opioid-related adverse effects and limiting efficacy. Oliceridine (TRV130) is a novel G protein-biased ligand at the μ-opioid receptor that differentially activates G-protein coupling while mitigating β-arrestin recruitment. Using data derived from both phase 1 studies in healthy volunteers as well as data from a phase 2 study examining the efficacy of oliceridine for the treatment of postbunionectomy pain, we have developed a population pharmacokinetic/pharmacodynamic model linking the pharmacokinetics of oliceridine to its effect on pain, as measured by the Numeric Pain Rating Scale score.

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Oliceridine is a novel G protein-biased ligand at the μ-opioid receptor that differentially activates G protein coupling while mitigating β-arrestin recruitment. Unlike morphine, oliceridine has no known active metabolites; therefore, analgesic efficacy is predictably linked to its concentration in the plasma. Oliceridine is primarily hepatically metabolized by CYP3A4 and CYP2D6.

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