Characteristics of drugs with linear pharmacokinetics. Apply onecompartment pharmacokinetics to describe steadystate serum drug concentrations following oral slowrelease dosing. Pharmacokinetics describes the movement greek kinesis of a drug greek pharmakon around the body. Apply onecompartment pharmacokinetics to single and multiple dosing following the intravenous and oral administration of drugs. A fundamental concept in pharmacokinetics is drug clearance, that is, elimination of drugs from the body, analogous to the concept of creatinine clearance.
In this lesson, we will learn all about how pregabalin works and what the body. Pharmacokinetics sometimes abbreviated as pk, is a branch of pharmacology dedicated to. For drugs to be effective they need to be able to move rapidly from blood plasma to other body fluids and tissues. Drug clearance cl is defined as the volume of plasma in. These linear models assumed that the pharmacokinetic parameters for a drug would not change when different doses or multiple doses of a drug were given. The halflife will remain constant, irrespective of how high the concentration. Principles of nonlinear pharmacokinetics reza mehvar1 school of pharmacy, texas tech university health sciences center, 0 south coulter street, amarillo tx 79106 prologue nonlinear pharmacokinetics, as opposed to the more commonly observed linear pharmacokinetics, is a topic of discussion in most basic pharmacokinetics courses offered to. You may have heard about epo in the context of sports because it is a performance enhancing drug ped.
Linear pharmacokinetics is socalled because the graph of the relationship between the various factors involved dose, blood plasma concentrations, elimination, etc. A much more uptodate version of this course is available at basic pharmacokinetics. Previous chapters discussed linear pharmacokinetic models using simple first order kinetics to describe the course of drug disposition and action. In clinical practice, clearance of a drug is rarely measured directly but is calculated as either of the following. Since, pk is defined as the study of the effects of a living organism on an. At a practical level, a drugs bioavailability can be defined as the proportion of the drug that reaches its site of action. Nonlinear pharmacokinetics applied biopharmaceutics. Apply the basic principles of interpretation of serum drug concentrations in practice. Introduction to pharmacokinetics and pharmacodynamics ashp. Pharmacokinetics is the study of drug absorption, distribution, metabolism, and excretion figure 461.
Pharmacokinetics is currently defined as the study of the. An example of a drug that has nonlinear pharmacokinetics pk is erythropoietin or epo. Nonlinear pharmacokinetics in other words, time or dose dependences in pharmacokinetic parameters can arise from factors associated with absorption, firstpass metabolism, binding, excretion and biotransformation. Linear and nonlinear kinetics of drug elimination i. This indicates that the instantaneous rate of change in drug concentration depends only on the current. A first course in pharmacokinetics and biopharmaceutics. Pharmacokinetics refers to what happens to a medication from entrance into the body until the exit of all traces. Kinetics resulting from saturable drug transfer, leading to. Overview of pharmacokinetics clinical pharmacology merck. When the dose of a drug is increased, we expect that the concentration at steady state will increase proportionately, i. The loglinear slope at the end of the concentrationtime curve can be used to. You may come across a phrase like the following and wonder what it means.
Clinical pharmacokinetics is the application of pharmacokinetic principles to the safe and effective therapeutic management of drugs in an individual patient. Four processes encompass the pharmacokinetics of a. Kinetics on the basis of a single capacitylimited pathway of elimination with or without simultaneous supplylimited elimination. Linear pharmacokinetics,the characteristic of drugs that indicates the instantaneous rate of change in drug concentration depends only on the current concentration. Formulas relating these processes summarize the pharmacokinetic behavior of most drugs see table formulas defining basic pharmacokinetic parameters. Basic pharmacokinetics sample chapter pharmaceutical press. A first course in pharmacokinetics and biopharmaceutics david bourne, ph. Pharmacokinetics and mechanisms of actions are two very important descriptors when it comes to understanding drugs. With some drugs, increased doses or chronic medication can cause deviations from the linear pharmacokinetic profile previously observed with single low doses of the same drug. Application of pharmacokinetics in early drug development. Nonlinearities in absorption and bioavailability can cause increases in drug concentrations that are disproportionately high or low relative to the change in dose. Introduction to pharmacokinetics vanderbilt university medical.
Principles of pharmacokinetics hollandfrei cancer medicine. Linear pharmacokinetics,the characteristic of drugs that indicates the instantaneous rate of change in drug concentration depends only on the current. Linear pharmacokinetics is socalled because the graph of the relationship between the various factors. Take the full course of digital signal processing what we provide 4 videos 2hand made notes with problems for your to practice 3strategy to score good marks in. Linear pharmacokinetics list of high impact articles. Nonlinear pharmacokinetics, as opposed to the more commonly observed linear pharmacokinetics, is a topic of discussion in most basic pharmacokinetics courses offered to pharmacy students.
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