Population Pharmacokinetic Modeling and Probability of Pharmacodynamic Target Attainment for Ceftazidime-Avibactam in Pediatric Patients Aged 3 Months and Older.

Increasing prevalence of infections caused by antimicrobial-resistant gram-negative bacteria represents a global health crisis, and while several novel therapies that target various aspects of antimicrobial resistance have been introduced in recent years, few are currently approved for children. Ceftazidime-avibactam is a novel β-lactam β-lactamase inhibitor combination approved for adults and children 3 months and older with complicated intra-abdominal infection, and complicated urinary tract infection or hospital-acquired ventilator-associated pneumonia (adults only in the United States) caused by susceptible gram-negative bacteria. Extensive population pharmacokinetic (PK) data sets for ceftazidime and avibactam obtained during the adult clinical development program were used to iteratively select, modify, and validate the approved adult dosage regimen (2,000-500 mg by 2-hour intravenous (IV) infusion every 8 hours (q8h), with adjustments for renal function).

Comparing the cardiovascular therapeutic indices of glycopyrronium and tiotropium in an integrated rat pharmacokinetic, pharmacodynamic and safety model.

Long acting inhaled muscarinic receptor antagonists, such as tiotropium, are widely used as bronchodilator therapy for chronic obstructive pulmonary disease (COPD). Although this class of compounds is generally considered to be safe and well tolerated in COPD patients the cardiovascular safety of tiotropium has recently been questioned. We describe a rat in vivo model that allows the concurrent assessment of muscarinic antagonist potency, bronchodilator efficacy and a potential for side effects, and we use this model to compare tiotropium with NVA237 (glycopyrronium bromide), a recently approved inhaled muscarinic antagonist for COPD.

Simulation of human intravenous and oral pharmacokinetics of 21 diverse compounds using physiologically based pharmacokinetic modelling.

Background: The importance of predicting human pharmacokinetics during compound selection has been recognized in the pharmaceutical industry. To this end there are many different approaches that are applied.

Methods: In this study we compared the accuracy of physiologically based pharmacokinetic (PBPK) methodologies implemented in GastroPlus™ with the one-compartment approach routinely used at Pfizer for human pharmacokinetic plasma concentration-time profile prediction.

Application of physiologically based pharmacokinetic modeling to understanding the clinical pharmacokinetics of UK-369,003.

5-[2-Ethoxy-5-(4-ethyl-piperazine-1-sulfonyl)-pyridin-3-yl]-3-ethyl-2-(2-methoxy-ethyl)-2,6-dihydro-pyrazolo[4,3-d]pyrimidin-7-one (UK-369,003) is a phosphodiesterase-5 inhibitor in clinical development at Pfizer. UK-369,003 is predominantly metabolized by cytochrome P450 3A4 and is also a substrate for the efflux transporter P-glycoprotein. The pharmacokinetics of UK-369,003 has been profiled after oral administration of 1 to 800 mg of an immediate release formulation to healthy volunteers.

Pharmacokinetic-pharmacodynamic modelling of the effect of Moxifloxacin on QTc prolongation in telemetered cynomolgus monkeys.

Introduction: Delayed ventricular repolarisation is manifested electrocardiographically in a prolongation of the QT interval. Such prolongation can lead to potentially fatal Torsades de Pointes. Moxifloxacin is a fluoroquinolone antibiotic which has been associated with QT prolongation and, as a result, is recommended by the regulatory authorities as a positive control in thorough QT studies performed to evaluate the potential of new chemical entities to induce QT prolongation in humans.

Modelling and PBPK simulation in drug discovery.

Physiologically based pharmacokinetic (PBPK) models are composed of a series of differential equations and have been implemented in a number of commercial software packages. These models require species-specific and compound-specific input parameters and allow for the prediction of plasma and tissue concentration time profiles after intravenous and oral administration of compounds to animals and humans. PBPK models allow the early integration of a wide variety of preclinical data into a mechanistic quantitative framework.