Intravenous administration does not involve absorption and, hence, there is no loss of drug. Factors affecting drug action norma nicholson ba, ma. Factors affecting gastrointestinal absorption of drugs springerlink. Request pdf factors affecting drug absorption and distribution the. With oral administration, several factors affect the absorption of a drug. Adjusting the dose to a patients needs is easier with solutions and suspensions than with solid dosage forms. The factors affecting absorption of drugs are related both to the drugs and to the body factors related to drugs. However, the effectiveness and safety of using anticoagulants is highly dependent on the patients ability to manage and take these complex, highrisk medicines. Overview of pharmacokinetics clinical pharmacology.
It is another vast and major field studied to comprehend kinetic of drugs. Certain changes within each of the four categories will produce uniform or predictable changes in drug. Pdf overview of factors affecting oral drug absorption. Factors affecting response to drugs overview of response to drugs. In patients with acid reflux disorders, proton pump inhibitors, such as omeprazole, render the stomach achlorhydric, which may also affect drug absorption. Some time, the drug is pseudotolerated by the patient, which cant be pseudotolerated by another one. Factors affecting drug absorption small intestine stomach. Pharmacokinetics in the older patient in general drug absorption, distribution in the body, activity, metabolism and excretion can all change as a result of ageing. Scribd is the worlds largest social reading and publishing site. Either youngs formula based on age or clarks formula based on weight can be used for calculating the doses for children but the formula based on body surface area is more reliable. For most tissues, passive aqueous diffusion through channels. Factors affecting gastrointestinal absorption of drugs. What are the factors affecting the dose and action of drugs.
Factors affecting the absorption of subcutaneously. Variations government medical college and hospital. The speed with which drugs move in and out of the body varies widely among different people. Coadministering orange juice, colas, or other acidic beverages can facilitate the absorption of some medications requiring an acidic environment. Because so many factors affect drug response, doctors must choose a drug appropriate for each person and must adjust the dose carefully. Large interindividual variations in drug response can arise from multiple genetic and environmental factors affecting drug absorption, distribution, biotransformation, excretion, interaction with receptor sites, or combinations of these.
In rectal absorption both low and high molecule weight compounds in a constant ratio of absorption. Many factors can affect a drugs absorption, distribution, metabolism, excretion, and ultimate effect. Certain combinations of drugs can slow down or speed up the effects. Variation in the response to equivalent drug concentrations arises because of various factors, such as differences in receptor number and structure, receptorcoupling mechanisms and physiological changes in target organs resulting from differences in genetics, age and health. A mechanistic approach to understanding the factors. Pharmaceutic factors affecting drug bioavailability. Agerelated changes in the kidneys, liver, and other organs will influence the way many medications work.
Pharmacists must also understand the relationship of drug dosage to. Rehabilitation considerations for individuals on cardiac medications. Greater the lipid water solubility coefficient, more is the lipid solubility of the drug and greater is the absorption. Some patientrelated factors eg, renal function, genetic makeup, sex, age can be used to predict the pharmacokinetic parameters in populations. In order to develop a drug product that elicits the desired therapeutic objective, the pharmaceutical scientist must. Factors affecting drug absorption free download as powerpoint presentation.
In order to develop a drug product that elicits the desired therapeutic objective, the pharmaceutical scientist must have a thorough understanding of the biopharmaceutic properties of the drug and drug product and the physiologic and pathologic factors affecting drug absorption from the application site. Product age and storage conditions product aging and improper storage conditions adversely affect b. It covers the components of therapeutic drug monitoring, the therapeutic index of drug and patientrelated factors such as drug interactions, the adverse reaction produced by these moieties and medication errors. Factors affecting patients perception on, and adherence. The factors affecting absorption of drugs are related both to the drugs and to the body. Overview of factors affecting oral drug absorption. Patient related factors, social factors, drug related factors, disease related factors and adr related factors. Patient related factors affecting drug absorption presented by,presented by, hinglajia hetalhinglajia hetal ratilalratilal. Pharmacokinetics of a drug depends on patientrelated factors as well as on the drugs chemical properties. Oral absorption of drugs from a pharmaceutical drug product.
Patient related factors include the structure of absorbing surface efflux and influx. In addition, it is common for multiple medical conditions to be present in older patients which can lead to a greater potential for medication problems due to polypharmacy. Patient related factors affecting on drug absorption, drug absorption, absorption, factors affecting, patient related factors. Several factors can affect the absorption of a drug. Nutritional status, multiple chronic diseases, and functional and cognitive deficits are other agerelated factors that may have an impact on drug therapy. Explain the meaning of the terms absorption, distribution, metabolism, and excretion. All drugs can produce adrs, but not all patients develop the same level and type of adrs. The role of the direct oral anticoagulants doacs in practice has been given extensive consideration recently, albeit largely from the clinicians perspective.
Drug absorption from pulmonary epithelia occurs only after inhaled drug deposits in the lung and undeposited aerosolized particles clear out of the lung in expired air. Physiological factors affecting absorption pharmatutor. Lipid water solubility coefficient is the ratio of dissolution of drug in lipid as compared to water. These factors can be related to either the insulin preparation, the injection sitepatient, or the injection technique.
List two physiologic factors that can alter each of the processes of absorption, distribution, and excretion. Physical properties and pharmaceutical manipulations influencing drug absorption. Normal bodily functions also vary with the time of day, thus affecting drug action. Pdf formulation considerations and factors affecting. In general, because of a loss of muscle mass, elderly persons are physically smaller.
The absorption, distribution, and excretion of drugs objectives after studying this chapter, the reader should be able to. After reading this article you will learn about the pharmaceutic factors affecting drug bioavailability. Drug absorption is a pharmacokinetic parameter that refers to the way a drug is absorbed from a pharmaceutical formulation into the bloodstream. Factors affecting the occurrence of adrs are subdivided into five groups. In general, children require smaller doses than adults. Patient factors 23 local environment ph, disease states tannic acid over burnt skin liver necrosis vascularity of absorbing surface timolol eye drops bradycardia while ointments did not. Each route of drug application presents special biopharmaceutic consideration in designing a drug product. The bioavailability of active drug can be varied from rapid and complete absorption to a slow. Factors affecting absorption of a drug from its dosage form. Ii patient related factorsphysiologic factors related to drug absorption.
Factors affecting drug absorption and distribution request pdf. A mechanistic approach to understanding the factors affecting drug absorption. Liquid dosage forms, therefore, have several practical advantages besides. Pharmaceutical factors a chemical factors b physicochemical properties. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Rehabilitation considerations for individuals on cardiac. Pharmaceutical factors a chemical factors b physicochemical properties of drug substances 1. Patient related factors affecting drug absorption presented by,presented by, hinglajia hetalhinglajia hetal ratilalratilal slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Pharmacokinetics in older patients rosemont pharma. Factors affecting drug absorption and distribution anaesthesia. Membrane structure and function the cell membrane is a semipermeable lipoid sieve containing numerous aqueous channels, as well as a variety of specialized carrier molecules. Factors affecting drug absorption flashcards quizlet. Overview of response to drugs explore from the merck manuals medical consumer version.