Pharmacy and Pharmaceutical Sciences Commons^™

Nanoformulation For Anticancer Drug Delivery: Enhanced Pharmacokinetics And Circulation, Gaurav Parekh

Doctoral Dissertations

In this study, we have explored the application of the Layer-by-Layer (LbL) assembly technique for improving injectable drug delivery systems of low soluble anticancer drugs (e.g. Camptothecin (CPT), Paclitaxel (PTX) or Doxorubicin (DOX)). For this study, a polyelectrolyte shell encapsulates different types of drug nanocores (e.g. soft core, nanomicelle or solid lipid nanocores).The low soluble drugs tend to crystallize and precipitate in an aqueous medium. This is the reason they cannot be injected and may have low concentrations and low circulation time in the blood. Even though these drugs when present in the cancer microenvironment have high anti-tumor inhibition, the …

Effects Of Pringle Maneuver And Partial Hepatectomy On The Pharmacokinetics And Blood–Brain Barrier Permeability Of Sodium Fluorescein In Rats, Mohammad K. Miah, Imam H. Shaik, Ulrich Bickel, Reza Mehvar

Pharmacy Faculty Articles and Research

Liver diseases are known to affect the function of remote organs. The aim of the present study was to investigate the effects of Pringle maneuver, which results in hepatic ischemia–reperfusion (IR) injury, and partial hepatectomy (Hx) on the pharmacokinetics and brain distribution of sodium fluorescein (FL), which is a widely used marker of blood–brain barrier (BBB) permeability. Rats were subjected to Pringle maneuver (total hepatic ischemia) for 20 min with (HxIR) or without (IR) 70% hepatectomy. Sham-operated animals underwent laparotomy only. After 15 min or 8 h of reperfusion, a single 25-mg/kg dose of FL was injected intravenously and serial …

Factors Affecting The Pharmacokinetics And Pharmacodynamics Of Pegylated Liposomal Irinotecan (Ihl-305) In Patients With Advanced Solid Tumors, Huali Wu, Jeffrey R. Infante, Vicki L. Keedy, Suzanne F. Jones, Emily Chan, Johanna C. Bendell, Wooin Lee, Whitney P. Kirschbrown, Beth A. Zamboni, Satoshi Ikeda, Hiroshi Kodaira, Mace L. Rothenberg, Howard A. Burris, William C. Zamboni

Pharmaceutical Sciences Faculty Publications

IHL-305 is a PEGylated liposomal formulation of irinotecan (CPT-11). The objective of this study was to evaluate the factors associated with interpatient variability in the pharmacokinetics and pharmacodynamics of IHL-305 in patients with advanced solid tumors. IHL-305 was administered intravenously once every 4 weeks as part of a Phase I study. Pharmacokinetic studies of the liposomal sum total CPT-11, released CPT-11, SN-38, SN-38G, 7-ethyl-10-[4-N-(5-aminopentanoic acid)-1-piperidino]-carbonyloxycamptothecin, and 7-ethyl-10-[4-amino-1-piperidino]-carbonyloxycamptothecin in plasma were performed. Noncompartmental and compartmental pharmacokinetic analyses were conducted using pharmacokinetic data for sum total CPT-11. The pharmacokinetic variability of IHL-305 is associated with linear and nonlinear clearance. Patients whose age …

Late-Occurring Vancomycin-Associated Acute Kidney Injury In Children Receiving Prolonged Therapy, Chad A. Knoderer, Allison L. Gritzman, Kristen R. Nichols, Amy C. Wilson

Scholarship and Professional Work – COPHS

Background: Acute kidney injury (AKI) in patients receiving vancomycin has been associated with trough concentrations ≥15 mg/L and longer therapy duration. The objective of this study was to determine the incidence and factors associated with late AKI in children receiving ≥8 days of vancomycin therapy. Methods: Children aged 30 days to 17 years who were admitted to our institution and received intravenous vancomycin for at least 8 days during January to December of 2007 and 2010 and had a suspected or proven gram-positive infection were included. Late AKI was categorized as AKI occurring after the first 7 days of therapy …

Stribild: A Review Of Component Characteristics And Combination Drug Efficacy, Derek E. Murrell, Jonathan P. Moorman, Sam Harirforoosh

Pharmacy Faculty Articles and Research

BACKGROUND: Numerous methods have been devised to combat human immunodeficiency virus (HIV) replication and disease progression. Composed of an integrase strand transfer inhibitor, a pharmacoenhancer, and two reverse transcriptase inhibitors, Stribild is a relatively new combination HIV drug formulated for once-a-day dosing.

METHODS: Relevant information, original research articles and reviews, were gathered primarily through the use of the PubMed database. The search was conducted without date restrictions in order to collect both historical and recent information concerning HIV, individual drugs, and combinations for a thorough overview.

RESULTS: Stribild, when taken with food, provides therapeutic drug concentrations as …

The Effect Of Transdermal Scopolamine For The Prevention Of Postoperative Nausea And Vomiting., María A Antor, Alberto A Uribe, Natali Erminy-Falcon, Joseph G Werner, Keith A Candiotti, Joseph V Pergolizzi, Sergio D Bergese

Pharmacy Articles

Postoperative nausea and vomiting (PONV) is one of the most common and undesirable complaints recorded in as many as 70-80% of high-risk surgical patients. The current prophylactic therapy recommendations for PONV management stated in the Society of Ambulatory Anesthesia (SAMBA) guidelines should start with monotherapy and patients at moderate to high risk, a combination of antiemetic medication should be considered. Consequently, if rescue medication is required, the antiemetic drug chosen should be from a different therapeutic class and administration mode than the drug used for prophylaxis. The guidelines restrict the use of dexamethasone, transdermal scopolamine, aprepitant, and palonosetron as rescue …

Effects Of Hepatic Ischemia-Reperfusion Injury On The P-Glycoprotein Activity At The Liver Canalicular Membrane And Blood-Brain Barrier Determined By In Vivo Administration Of Rhodamine 123 In Rats, M. K. Miah, Imam H. Shaik, Ulrich Bickel, Reza Mehvar

Pharmacy Faculty Articles and Research

Purpose To investigate the effects of normothermic hepatic ischemia-reperfusion (IR) injury on the activity of P-glycoprotein (P-gp) in the liver and at the blood-brain barrier (BBB) of rats using rhodamine 123 (RH-123) as an in vivo marker.

Methods Rats were subjected to 90 min of partial ischemia or sham surgery, followed by 12 or 24 h of reperfusion. Following intravenous injection, the concentrations of RH-123 in blood, bile, brain, and liver were used for pharmacokinetic calculations. The protein levels of P-gp and some other transporters in the liver and brain were also determined by Western blot analysis.

Results P-gp protein …

Prediction Of Human Systemic, Biologically Relevant Pharmacokinetic (Pk) Properties Using Quantitative Structure Pharmacokinetic Relationships (Qspkr) And Interspecies Pharmacokinetic Allometric Scaling (Pk-As) Approaches For Four Different Pharmacological Classes Of Compounds, Gopichand Gottipati

Theses and Dissertations

This research developed and validated QSPKR models for predicting in-vivo human, systemic biologically relevant PK properties (i.e., reflecting the disposition of the unbound drug) of four, preselected, pharmacological classes of drugs, namely, benzodiazepines (BZD), neuromuscular blocking agents (NMB), triptans (TRP) and class III antiarrhythmic agents (AAR), as well as PK allometric scaling (PK-AS) models for BZD and NMB, using pertinent human and animal systemic PK information (fu, CLtot, Vdss and fe) from published literature. Overall, lipophilicity (logD7.4) and molecular weight (MW) were found to be the most important and statistically significant molecular properties, affecting biologically relevant systemic PK properties, and …

Tobramycin Disposition In The Lung Following Airway Administration, Min Li

Theses and Dissertations

Tobramycin disposition following airway administration was evaluated by meta-analysis of human data in the literature and, experimentally, using a realistic ex vivo model, the isolated perfused rat lung preparation (IPRL). Pulmonary bioavailability of inhaled tobramycin in published studies was re-evaluated separately for CF and healthy adults, with the drug’s intrinsic pharmacokinetic (PK) parameters obtained from intravenous (IV) studies in the literature. While large variations in tobramycin’s clearance precluded accurate assessment of its bioavailability, the results were indicative of substantial pulmonary absorption, in spite of its hydrophilic and poly cationic properties. To explore its disposition kinetics and mechanisms following airway administration, …

Physiological And Pharmacokinetic Effects Of Oral 1,3-Dimethylamylamine Administration In Men, Brian Schilling, Kelley Hammond, Richard Bloomer, Chaela Presley, Charles Yates

Kinesiology and Nutrition Sciences Faculty Research

No abstract provided.

Assessment Of The Drug-Drug Interaction Potential Of Anionic Components In The Diet And Herbal Medicines On Organic Anion Transporters (Slc22 Family), Li Wang

Theses and Dissertations

Numerous natural products are widely used as first-line/alternative therapeutics and dietary supplements in both western and eastern society. However, the safety and efficacy profiles for herbal products are still limited. Organic anion transporters (OATs; SLC22 family) are expressed in many barrier organs and mediate in vivo body disposition of a broad array of endogenous substances and clinically important drugs. As some dietary flavonoids and phenolic acids were previously demonstrated to interact with OATs, it is necessary to explore the potential interaction of such components found in natural products in order to avoid potential OAT-mediated drug-drug interactions (DDIs). The inhibitory effects …

Vancomycin And Gentamicin Pharmacokinetic Alterations In An Adolescent Amputee, Kristen R. Nichols, Kari M. Edison, Michelle D. Rosenbaum, Chad A. Knoderer

Scholarship and Professional Work – COPHS

A 14-year-old male with bilateral above-the-knee amputations presented to our hospital for treatment of a skin and soft-tissue infection. We report the experience of vancomycin and gentamicin therapy in this patient. Because these medications require weight-based dosages and pharmacokinetic monitoring of serum levels, it was necessary to obtain peak and trough levels of the two drugs in order to determine the pharmacokinetic differences in this patient compared to those in an adolescent male without amputations. To our knowledge, this is the first report describing pharmacokinetic differences in an adolescent amputee.

High Dose Simvastatin As A Potential Anticancer Therapy In Leukemia Patients, Tamer Ahmed

Theses and Dissertations--Pharmacy

Simvastatin is a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor that is used for the treatment of hyperlipidemia. Simvastatin has recently been studied for its potential use in cancer therapy. In-vitro studies have shown that simvastatin displays anticancer activity, but at concentrations unlikely to be achieved in patients being receiving typical antihyperlipidemic treatment doses. Thus, several clinical trials were conducted to study the tolerability of high dose statins in cancer patients. The maximum tolerated dose of simvastatin was determined to be 15 mg/kg/day, 25-fold higher than a typical dose. However, it is not known if simvastatin plasma concentrations can reach those …

The Pharmacokinetics Of Metal-Based Engineered Nanomaterials, Focusing On The Blood-Brain Barrier, Mo Dan

Theses and Dissertations--Pharmacy

Metal-based engineered nanomaterials (ENMs) have potential to revolutionize diagnosis, drug delivery and manufactured products, leading to greater human ENM exposure. It is crucial to understand ENM pharmacokinetics and their association with biological barriers such as the blood-brain barrier (BBB). Physicochemical parameters such as size and surface modification of ENMs play an important role in ENM fate, including their brain association. Multifunctional ENMs showed advantages across the highly regulated BBB. There are limited reports on ENM distribution among the blood in the brain vasculature, the BBB, and brain parenchyma.

In this study, ceria ENM was used to study the effect of …

In-Vitro Pk/Pd Profiling And Modeling Of The Anti-Sickling Agents, 5-Hydroxymethyl Furfural (5-Hmf) And Novel Synthetic Allosteric Effectors Of Hemoglobin (Aeh) In Human Whole Blood, Apurvasena Parikh

Theses and Dissertations

Introduction. 5-HMF and novel INN-compounds are left-shifting AEH, shown to have anti-sickling action by forming transiently covalent Schiff-base adducts with hemoglobin (Hb), thereby increasing the Hb O2-affinity. They are hypothesized to be substrates for aldehyde dehydrogenase (ALDH) in the liver and red blood cells (RBC). Methods. Biopharmaceutical assessments were made for AEH, using calculated physicochemical properties. Their in-vitro hepatic metabolism (mediated by ALDH) was characterized using hepatic cytosol, and in-vitro-in-vivo extrapolations (IVIVE) were made. Inter-species differences in hepatic cytosolic ALDH activity were investigated using acetaldehyde as a model substrate in different mammalian species. Time- and concentration-dependent in-vitro disposition of 5-HMF …

In Vitro In Vivo Methods And Pharmacokinetic Models For Subcutaneously Administered Peptide Drug Products, Amit Somani

Theses and Dissertations

Over the last several years, injectable drugs have been a growing area for the treatment of various therapeutic conditions and they are projected to comprise an even larger proportion among the drugs that will be available in the years to come. The injectable drugs are administered by various routes such as intramuscular (IM), intravenous (IV), subcutaneous (SC) and others, however, the majority of these drugs are administered subcutaneously. Even though subcutaneous delivery has been utilized for a number of years, very little is known about the processes governing the absorption of macromolecules from the interstitial space; and the resulting impact …

Prediction Of Human Systemic, Biologically Relevant Pharmacokinetic Properties Based On Physicochemical Properties Of Calcium Channel Blockers, Tafif Abdullah Al

Theses and Dissertations

This research explored quantitative relationships (QSPKR) between different molecular descriptors and pertinent, systemic PK properties for 14 calcium channel blockers (CCB). Physicochemical properties (PC) such as molecular weight (MW), molar volume (MV), calculated logP (clogP), pKa, calculated logD7.4 (clogD), % ionized at pH 6.3 and pH 7.4, hydrogen bond donors (HBD), hydrogen bond acceptors (HBA), and number of rotatable bonds (nRot) were chosen as possible predictor variables for systemic PK properties for CCB, obtained from pertinent literature, assessing the PK of CCB after intravenous administration to healthy humans. All PC properties and molecular descriptors were computed using ACD-solubility/DB 12.01. Total …

Preclinical Study Of Potential Antiglioma Novel Tetrahydroisoquinoline Analogs: Pharmacokinetics And Mechanism Of Action, Fei Ma

Theses and Dissertations (ETD)

Gliomas, the tumors of glial cells, account for 80% of primary malignant brain tumors. In 2011, there were about 18,300 new cases of maligant gliomas in the United States alone. Patients with glioblastoma multiforme or anaplastic astrocytoma, the two major types of malignant gliomas, have a median survival of 14 months or 2 to 3 years, respectively. Therefore novel treatments for malignant glioma are urgently needed.

A novel series of tetrahydroisoquinoline derivatives with antiglioma activity has been undergoing drug metabolism/pharmacokinetics (DMPK)-guided lead optimization. EDL-291 was result from structure modification of last generation compound EDL-155. Its preclinical pharmacokinetics were characterized in …

Pharmacokinetic/Pharmacodynamic (Pk/Pd) Modeling Of Anti-Neoplastic Agents, Daniel Lexcen, Ahmed H. Salem, Walid F. Elkhatib, Virginia Haynes, Ayman Noreddin

Pharmacy Faculty Books and Book Chapters

"Development of tumor resistance to chemotherapeutics is related to inherent tumor variations regarding sensitivity to chemotherapeutics and to sub-optimal dosing regimens, including variation in patient pharmacokinetics that result in suboptimal exposure of tumor cells to anti-neoplastic drugs [1, 2]. The rate and extent of drug efficacy depends on the extent of drug exposure at the tumor site and the time above the effective concentration [3]. In vitro models that incorporate these pharmacokinetic and pharmacodynamic (PK/PD) principles to optimize therapeutic response may be considered the method of choice for optimizing dosing schedules before translating data from static assays to animals and …

Application Of Pharmacokinetics/Pharmacodynamics (Pk/Pd) In Designing Effective Antibiotic Treatment Regimens, Ghada F. Ahmed, Ayman Noreddin

Pharmacy Faculty Books and Book Chapters

"Designing antibiotic dosing regimens is often not optimal and the dose-response relationship for most antibiotics is not well-known1. Both Pharmacokinetics (PK) and Pharmacodynamics (PD) are characteristics of antimicrobial agents that should be considered in the development of effective antibiotic therapy. By linking the concentration time profile at the site of action to the drug effect (PK/PD), the effect of varying dosage regimens against pathogens could be simulated enabling the identification of effective dosage strategies. It is known that inadequate antibiotic dosing could not only lead to a therapeutic failure, but also to the development of bacterial resistance. Importantly, the evolution …

Effects Of Simulations On The Learning Of Pharmacokinetic Concepts, Reza Mehvar

Pharmacy Faculty Articles and Research

Objective: Although the use of computer simulations in pharmacokinetics courses is not new, the data on the effects of simulation on student learning are scarce. The objective of this study was to design and evaluate the use of Web-based simulations on the learning of pharmacokinetic concepts by doctor of pharmacy (PharmD) students.

Method: Six online modules were designed to allow the instructor and students to use “what-if” scenarios for understanding the effects of various dosage regimens and/or pharmacokinetic parameters on the plasma concentration-time courses of drugs. The designed modules were intravenous and oral pharmacokinetic concepts, bioavailability, intravenous infusion, …

Ceria-Engineered Nanomaterial Distribution In, And Clearance From, Blood: Size Matters, Mo Dan, Peng Wu, Eric A. Grulke, Uschi M. Graham, Jason M. Unrine, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

AIMS: Characterize different sized ceria-engineered nanomaterial (ENM) distribution in, and clearance from, blood (compared to the cerium ion) following intravenous infusion.

MATERIALS & METHODS: Cerium (Ce) was quantified in whole blood, serum and clot (the formed elements) up to 720 h.

RESULTS: Traditional pharmacokinetic modeling showed best fit for 5 nm ceria ENM and the cerium ion. Ceria ENMs larger than 5 nm were rapidly cleared from blood. After initially declining, whole blood 15 and 30 nm ceria increased (results that have not been well-described by traditional pharmacokinetic modeling). The cerium ion and 5 and 55 nm ceria did not …

The Importance Of Active Learning And Practice On The Students' Mastery Of Pharmacokinetic Calculations For The Intermittent Intravenous Infusion Dosing Of Antibiotics, Reza Mehvar

Pharmacy Faculty Articles and Research

Estimation of pharmacokinetic parameters after intermittent intravenous infusion (III) of antibiotics, such as aminoglycosides or vancomycin, has traditionally been a difficult subject for students in clinical pharmacology or pharmacokinetic courses. Additionally, samples taken at different intervals during repeated dose therapy require manipulation of sampling times before accurate calculation of the patient-specific pharmacokinetic parameters. The main goal of this study was to evaluate the effectiveness of active learning tools and practice opportunities on the ability of students to estimate pharmacokinetic parameters from the plasma samples obtained at different intervals following intermittent intravenous infusion.

Hepatic Immunosuppressive Effects Of Systemically- Administered Novel Dextran-Methylprednisolone Prodrugs With Peptide Linkers In Rats, Imam H. Shaik, Hitesh K. Agarwal, Keykavous Parang, Reza Mehvar

Pharmacy Faculty Articles and Research

The hepatic immunosuppressive activities of two novel dextran prodrugs of methylprednisolone (MP) containing one (DMP1) or five (DMP5) amino acids as linkers were studied in rats. At various times (02 weeks) after intravenous administration of single 5 mg/kg (MP equivalent) doses of each prodrug or MP succinate (MPS), livers were isolated and immunologically stimulated ex vivo with lipopolysaccharide. The concentrations of tumor necrosis factor (TNF)-a in the outlet perfusate were then quantitated to assess immune response. Additionally, the concentrations of DMP1, DMP5, and/or MP were measured in the liver. MPS, DMP5, or DMP1 injections caused a maximum of 48.9%, 63.5%, …

Bevacizumab Effect On Topotecan Pharmacokinetics In A Murine Orthotopic Rhabdomyosarcoma Xenograft Model, Zaifang Huang

Theses and Dissertations (ETD)

Increasing evidence suggests that inhibition of vascular endothelial growth factor (VEGF) can transiently normalize tumor vasculature, thereby improving delivery of systemic chemotherapy. Bevacizumab (BEV), an anti-VEGF antibody, has been shown to transiently normalize tumor vasculature by increasing tumor vessel maturity, decreasing tumor vessel permeability, and increasing tumor oxygenation in an Rh30 orthotopic rhabdomyosarcoma xenograft model. However, the effects of BEV on the pharmacokinetics of TPT and the antitumor activity of TPT have not been evaluated. This study aimed to investigate the effect of BEV on TPT systemic and tumoral pharmacokinetics and to determine how these changes affect the efficacy of …

Preclinical Pharmacology Of The Mdm2 Antagonist Nutlin-3a, Fan Zhang

Theses and Dissertations (ETD)

Nutlin-3a is an MDM2-p53 interaction antagonist that is under investigation in preclinical models for a variety of pediatric malignancies, including neuroblastoma, retinoblastoma, leukemia, and rhabdomyosarcoma. In the current research, we conducted preclinical pharmacology studies of nutlin-3a to evaluate the synergistic effect of the nutlin-3a and topotecan combination on neuroblastoma cell growth, to assess the effect of nutlin-3a on breast cancer resistance protein (BCRP), and to characterize the disposition of nutlin-3a in the mouse plasma and multiple tissues.

Activating the p53 pathway might offer a new therapy for neuroblastoma. In the first part of the study, we assessed the effect of …

Pharmacokinetic And Pharmacodynamic Studies Of A Novel Spectinamide Series Of Antituberculosis Agents, V. N. R. Pavan Kumar Vaddady

Theses and Dissertations (ETD)

Spectinamides are novel amide derivatives of the antibiotic spectinomycin that have emerged as a new class of agents to treat tuberculosis. These agents showed potent in vitro activity against Mycobacterium tuberculosis (MTB) compared to spectinomycin and in a preliminary in vivo study in interferon gamma (IFN‑γ) knockout mice, spectinamide Lee1329 reduced the lung bacillary load of TB comparable to streptomycin. We hypothesized that the application of an iterative pharmacokinetics and pharmacodynamics (PK/PD) guided approach would facilitate the optimization of these lead compounds suitable for further development.

A series of in vitro experiments including parallel artificial membrane permeability assay (PAMPA), microsomal …

Cefuroxime Pharmacokinetics In Pediatric Cardiovascular Surgery Patients Undergoing Cardiopulmonary Bypass, Chad A. Knoderer, Sarah A. Saft, Scott G. Walker, Markl D. Rodefeld, Mark W. Turrentine, John W. Brown, Daniel P. Healy, Kevin M. Sowinski

Scholarship and Professional Work – COPHS

Objectives

The objective of this study was to determine the pharmacokinetics of cefuroxime in children undergoing cardiopulmonary bypass (CPB) for cardiovascular surgery.

Design

A prospective study.

Setting

A tertiary pediatric teaching hospital.

Participants

Infants and children undergoing CPB were enrolled in the study.

Intervention

An initial dose (mean, 24.2 ± 1.6 mg/kg) of cefuroxime was administered before surgical incision, and a second dose (mean, 14.4 ± 7.9 mg/kg) was administered in the CPB prime solution. Serial blood samples were obtained before, during, and after the CPB process. Samples were shipped on dry ice to the analytic laboratory and concentrations determined …

Biopharmaceutic And Pharmacokinetic Evaluation Of Hesperidin And Hesperetin For Ocular Delivery, Ramesh Srirangam

Electronic Theses and Dissertations

The bioflavonoid hesperidin and its aglycone hesperetin are promising candidates for the treatment of diabetic retinopathy and diabetic macular edema because of their pharmacological properties. The objective of this project was to characterize the biopharmaceutic and pharmacokinetic characteristics of hesperidin and hesperetin for ocular delivery, especially with respect to the distribution of these compounds to the posterior segment of the eye. Hesperidin and hesperetin were found to be water insoluble compounds. Although they demonstrated good permeability across the ocular tissues, hesperetin's permeability was found to be higher than that of hesperidin. Hesperidin demonstrated symmetrical transcorneal and transretinal permeation whereas hesperetin …

The Effects Of Laropiprant, A Selective Prostaglandin D₂ Receptor 1 Antagonist, On The Antiplatelet Activity Of Clopidogrel Or Aspirin., Aimee Dallob, Wen-Lin Luo, Julie Mabalot Luk, Lisa Ratcliffe, Amy O Johnson-Levonas, Jules I Schwartz, Victor Dishy, Walter K. Kraft, Jan N De Hoon, Anne Van Hecken, Inge De Lepeleire, Waldemar Radziszewski, John A Wagner, Eseng Lai

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Laropiprant (LRPT) is being developed in combination with Merck's extended-release niacin (ERN) formulation for the treatment of dyslipidemia. LRPT, an antagonist of the prostaglandin PGD₂ receptor DP1, reduces flushing symptoms associated with ERN. LRPT also has affinity for the thromboxane A₂ receptor TP (approximately 190-fold less potent at TP compared with DP1). Aspirin and clopidogrel are two frequently used anti-clotting agents with different mechanisms of action. Since LRPT may potentially be co-administered with either one of these agents, these studies were conducted to assess the effects of steady-state LRPT on the antiplatelet activity of steady-state clopidogrel or aspirin. Bleeding time …