The class i drug would become displaced would not be bound to albumin and would become free in the blood and the class ii drug would bind to albumin and have excess in the blood they compete with each other. Factors contributing to variability in drug pharmacokinetics. General adverse drugs reactions of antihelminthics 1. Feb 27, 2019 when a drug is absorbed and enters the systemic circulation, it is naturally distributed throughout the fluid and tissues in the body. Many factors can affect a drugs absorption, distribution, metabolism, excretion, and ultimate effect. The pharmacokinetic properties of a drug comprise the relationship between its absorption, distribution and inactivation. Membrane permeability tends to restrict the transfer and distribution of drugs once they are delivered to the tissue. Drug distribution once a drug enter in to the blood stream, the drug is subjected to a number of processes called as disposition processes that tend to lower the plasma concentration. Start studying chapter 1 factors that affect drug distribution. Absorption, distribution, metabolism and excretion of drug. Which of the following measures has the potential to increase the amount of the free drug that is available to body cells. The kinetics of drug distribution to various tissues and body compartments is profoundly affected by the remarkable changes in fetal body composition that occur during pregnancy. This corresponds to the linear onecompartment open model. Typically, distribution is much more rapid than elimination, is accomplished via the circulation, and is influenced by regional blood flow.
Chemicals foods, medicines, drugs of abuse, industrial chemicals can enter the human body by various means including ingestion, inhalation, injection intravenous, subcutaneous, intramuscular, skin application, use of a suppository and application to mucous membranes eye, oral and nasal cavities. Factors affecting drug absorption and distribution request pdf. O factors affecting drug metabolism pharmaceutical chemistry. The interrelationship between drug distribution, biotransformation and excretion and the drug in figure 1. Metabolism is the study of how a drug is degraded within the body and excretion is the study of how a drug is exited from the body. Factors affecting drug absorption and distribution. Question 3 which of the following affects drug distribution throughout the body. Factors affecting drug action flashcards from mandy d. There are, however, factors outside the body that can also have a profound influence on drug metabolism. Absorption, distribution, and storage of chemicals biology. Which of the following affects drug distribution throughout. The body can be exposed to these factors by design e. The action of a drug requires the presence of an adequate concentration of the drug in the fluid bathing the target tissue, and this, in turn, is determined by the dynamic relationship between absorption into the plasma following administration, the extent and rate of its distribution and the rate of.
An adults total body water accounts for approximately 60% of body weight. Other factors affecting drug absorption and distribution. Flashcards for fundamentals of pharmacology for veterinary technicians learn with. Chapter 1 factors that affect drug distribution quizlet. Drug distribution is a subject that is covered in a branch of. On the other hand, when distribution is prolonged, the concentration versus time curve observed is the one shown in fig. Absorption process of the intake of the drug into the body distribution process of the dispersion of the drug into the blood stream and tissues metabolism. Factors that affect the distribution of drugs in the body are lipid solubility, the bloodbrain barrier, protein binding, and the presence of active and passive transport mechanisms.
In pharmacokinetics, the distribution is described by the parameter v, the apparent volume of distribution. The article is a continuation of basics of antihelminthics. Choose from 253 different sets of factors affecting drug dosage flashcards on quizlet. Administering the drug intravenously rather than orally. Inside the body, drugs move in the blood to different parts of the body.
A coffee gets you stimulated, alcohol makes you depressed. The other major factor which determines the rate of drug distribution is blood perfusion. Low plasma binding or high tissue binding or high lipophilicity usually means an extensive tissue distribution. The speed with which drugs move in and out of the body varies widely among different people. How drugs affect the brain and nervous system the effects of drugs. Drug distribution refers to the movement of a drug to and from the blood and various tissues of the body for example, fat, muscle, and brain tissue and the relative proportions of drug in the tissues. The drugs are present in free or bound form and different processes or mechanisms affect their. Pathological and physiological factors affecting drug. Study chapter 1 basic pharmacology flashcards at proprofs not all key terms from the chapter will be on here, since im basing this on a study guide provided by the instructor for the cumulative final exam. Movement of the drug and their metabolites out of the body. This is shown to illustrate that drugs can affect each other. The following table highlights some of these other factors.
Drug distribution the size of fluid compartments of the body. Factors affecting drug metabolism free download as powerpoint presentation. Many factors can affect a drug s absorption, distribution, metabolism, excretion, and ultimate effect. Nov 07, 20 drug distribution the size of fluid compartments of the body. Competition for drug binding sites affects the amount of drug available for action in the body. Unit 1 introduction to pharmacology flashcards quizlet. Distribution is affected by normal physiologic changes of aging, which include a higher percentage of fat to lean body mass, a decrease in total. Describe how drug binding to plasma proteins can effect drug distribution and elimination as well as being a potential source of drug drug interactions. Therefore, in order to get the best possible treatment, it is important that your healthcare professional factors in all these elements before prescribing a drug. As the fluid passes through, water and nutrients are reabsorbed. In the kidney, most of the fluid in the blood is released into one end of the nephron. Learn factors affecting drug dosage with free interactive flashcards. Total body water content decreases from about 94% of total body weight at 16 weeks of gestation to about 76% at term.
The process of transferring a drug from the bloodstream to tissues is referred to as distribution. Distribution process is carried out by the circulation of blood, one of the compartment is always the blood or the plasma and the other represents extra vascular fluids. Olavi pelkonen, jorma ahokas encyclopedia of life support systems eolss in principle, the access of a drug to its site of action is dependent on two broad processes. Measurement of drug concentration in the blood, serum or plasma is the most direct approach to assess the pharmacokinetics of drug in body. A presence of food in the gastrointestinal tract b increase in hepatic enzymes c protein binding d high blood levels ans. Drug distribution once in the blood, drugs are simultaneously distributed throughout the body and eliminated. Accordingly, deviations between drug response within or between individuals may be ascribed eithertoproductbioavailabilityi. Oct 24, 2014 drug distribution once a drug enter in to the blood stream, the drug is subjected to a number of processes called as disposition processes that tend to lower the plasma concentration. The action of a drug requires the presence of an adequate concentration of the drug in the fluid bathing the target tissue, and this, in turn, is determined by the dynamic relationship between absorption into the plasma following administration, the extent and rate of its distribution and the rate of inactivation by the body. Impaired renal function may lead to a clinically significant accumulation of drugs eliminated by the kidneys, if more than 50% of the dose is normally excreted unchanged in the urine and the renal function is less than 50% of the. Confined to specific tissue may not be the site of action for that drug ex. Which of the following affects drug distribution throughout the body.
Distribution of a drug is not uniform throughout the body because different tissues receive the drug from plasma at different rates and to different extents. After a drug has been absorbed into the circulatory system. Learn vocabulary, terms, and more with flashcards, games, and other study tools. The process by which a drug reversibly leaves the blood stream and enters the interstitium extracellular fluid andor the cells or tissues. Differences in drug distribution among the tissue essentially arise as result of a number of factors.
Which of the following methods would be the most appropriate for the nurse to use when administering the medication. Question 4 an unconscious patient has been brought to the hospital, and the physician has prescribed a lifesaving drug to be administered parenterally. Distribution of body fat and fluids is different between men and women. Theoretical volume that drugs have to distribute in body. Drugs are also distributed to tissues where it has no effect. Drug response can be affected by a wide range of factors, including genetics, age and certain environmental considerations. Distribution in pharmacology is a branch of pharmacokinetics which describes the reversible transfer of a drug from one location to another within the body once a drug enters into systemic circulation by absorption or direct administration, it must be distributed into interstitial and intracellular fluids. Other activities to help include hangman, crossword, word scramble, games, matching, quizes, and tests.
Chapter 1 basic pharmacology flashcards by proprofs. Both protein binding and altered ph of extracellular fluids affect drug distribution. Elimination which involves irreversible loss of drug from the body. Distribution is the study of how the blood stream carries a drug throughout the body. Distribution process is carried out by the circulation of blood, one of the compartment is always the blood or the plasma and the other represents extra vascular fluids and other body tissues. Start a free trial of quizlet plus by thanksgiving lock in 50% off all year try it free. The simplest factor determining distribution is the amount of blood flow to body tissues. Drug distribution describes the process which transports a drug to its site of action, to other storage sites in the body, and to organs of metabolism and excretion. Some drugs are distributed more easily in the fatty tissue and some in the lean muscular tissue. Feb 27, 2019 drug elimination is the process by which pharmaceutical substances are removed from the body.
A drug must be distributed to its site of action to have an effect. Drug distribution is the amount of drug that enters various parts of the body tissues, and organs. Distribution drug distribution to various parts of the body differs between adults and newborns. Pharmacokinetics adme measurement of drug concentration 1. Factors affecting drug action at texas womens university. A patient has been prescribed an oral drug that is known to have a high firstpass effect. This includes absorption, distribution, metabolism and excretion. Distribution of drugs is influenced by total body water, proteinbinding of drugs, and changes in the makeup and size of organs. The distribution of drugs in the body depends on their lipophilicity and protein binding. Blood perfusion rate the rate at which blood perfuses to different organs varies widely. In most tissues, drugs can easily leave the vasculature through spaces between the cells. Blood perfusion rate the rate at which blood perfuses to different organs. The passage of drugs across cell membranes is a key part of most.
If the drug distribution in the body is instantaneous and homogeneous, the plasma concentration versus time curve shows no apparent distribution phase. The physiological movement of drugs within the body and includes the. Free pharmacology flashcards about pharmacology ch 110. Distribution which involves reversible transfer of a drug between compartments. All drugs are eventually eliminated from the body, although there are various pathways that may be. Movement of a drug from the site of administration to body fluids. Drug distribution in special compartments and bioavailability. In addition to protein availability, other factors may affect drug absorption and distribution in the body as a whole or at specific sites within the body. The process of removing a drug or its metabolites from the body occurs primarily in the urine other routes of excretion from the body include in bile, sweat. Its because of the way the drug interacts with your body.
Drug distribution drugs msd manual consumer version. Factors affecting drug metabolism drug metabolism metabolism. Factors affecting renal excretion of drugs include. A drug must be distributed to its site of actionsite of action drugs from the blood to the site of action. Factors that affect the distribution of drugs in the body are.
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