Current pharmaceutical biotechnology
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RNA interference (RNAi) is a fundamental mechanism of gene regulation and has been harnessed to produce a new class of drugs for treatment of various diseases. A key issue in these applications is how to effectively deliver RNAi therapeutics into target cells. This review is focused on advances in RNA delivery in vivo. ⋯ Approaches to RNA delivery are divided into three categories in this review: biological, chemical, and physical. Advantages and disadvantages of each method are discussed. At present, effective delivery of RNAi therapeutics in vivo is still a challenge although significant advances have been made in this field.
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Pathophysiological changes are common in critically ill patients, and can alter the time course of drug concentrations following dosing. The latter is termed pharmacokinetics (PK), and describes the relationship between dose administered and drug concentrations in plasma. Thus, modifications in PK necessitate dose adjustment, to optimize drug therapy in critical care. ⋯ This information is useful with assisting individualized dosing in the clinic. While the above methods are suitable for research, they are too time-consuming in the clinical setting, and Bayesian approaches have been adopted to optimize dosing. These methods, together with POPPK and appropriate study design are recommended for improved dosing in critical care.
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Curr Pharm Biotechnol · Dec 2011
ReviewPhysiological changes in the critically ill patient with sepsis.
Intensive care medicine deals with the critically ill; these patients usually have multiple organ failure, and complex medical conditions. The mortality in Australia and New Zealand among this population is approximately 16.1%, with approximately 24.2% having existing co-morbidities, and 23.4% of these patients experiencing sepsis or septic shock. Sepsis is a clinical syndrome that traditionally was regarded as a physiological maladaptive response to a foreign pathogen and ranges in disease severity from simple sepsis to septic shock, a life threatening condition, associated with multiple organ failure. ⋯ There are also alterations in the fluid compartments of the septic critically ill, that results in an altered volume of distribution, and ultimately decreased antibiotic concentrations at their site of action. This article will examine and review in detail the septic critically ill patient, and the effects that sepsis has on physiology and the resulting altered antibiotic pharmacokinetics and pharmacodynamics. Current knowledge suggests that the medical prescriber should be weary of antibiotic dosing in the septic critically ill, and consider alternative dosing regimes that are individualized to the patient in order to maximize efficacy.
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Curr Pharm Biotechnol · Dec 2011
ReviewRelevance of pharmacokinetic and pharmacodynamic modeling to clinical care of critically ill patients.
Efficacious therapy is of utmost importance to save lives and prevent bacterial resistance in critically ill patients. This review summarizes pharmacokinetic (PK) and pharmacodynamic (PD) modeling methods to optimize clinical care of critically ill patients in empiric and individualized therapy. While these methods apply to all therapeutic areas, we focus on antibiotics to highlight important applications, as emergence of resistance is a significant problem. ⋯ In vitro infection models such as the hollow fiber and one-compartment infection models allow one to study antibiotic-induced bacterial killing and emergence of resistance of mono- and combination therapies over clinically relevant treatment durations. Mechanism-based (and empirical) PK/PD modeling can incorporate effects of the immune system and allow one to design innovative dosage regimens and prospective validation studies. Mechanism-based modeling holds great promise to optimize mono- and combination therapy of anti-infectives and drugs from other therapeutic areas for critically ill patients.
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Curr Pharm Biotechnol · Dec 2011
ReviewUsing PK/PD to optimize antibiotic dosing for critically ill patients.
Antibiotic prescription for critically ill patients is a complicated process because of the pharmacokinetic differences of this patient population with non-critically ill patients and the lack of robust informative studies. This article seeks to review the available literature describing dosing requirements for optimized treatment of critically ill patients and to discuss a framework to rationally address complex cases by outlining the suggested processes for optimal achievement of pharmacokinetic/ pharmacodynamic targets. A variety of papers exist describing the effect of pathophysiology on antibiotic kinetics. ⋯ Dysfunction of the cardiovascular and renal systems in particular is problematic and can lead to potentially sub-therapeutic antibiotic concentrations in blood and in interstitial fluid. In response to altered pharmacokinetics, dose regimens that adhere to the pharmacodynamics of the antibiotic are essential. In the absence of validated dosing algorithms, therapeutic drug monitoring data and susceptibility data of the infecting pathogen should be inputted into a Bayesian software program that include population pharmacokinetic models to calculate dosing regimens that are personalized for the critically ill patient.