Placebo this is an inert substance which is given in the garb of medicine. The aim of the study was to explore the influence of social factors on adolescent drug abuse. Physicochemical parameters affecting drug action posted jun 29, 2014, 10. While these statistics can be difficult to fully understand because of the fact that different people abuse substances for. Drug response can be affected by a wide range of factors, including genetics, age and certain environmental considerations. Note that this just concerns metabolism of the drug. Because so many factors affect drug response, doctors must choose a drug appropriate for each person and must adjust the dose carefully. Factors affecting dissolution rate divided into five classes a. Although a physician prescribes the amount to be given, you need to know how and why these quantities are determined.
Substance abuse and socioeconomic factors recovery. Factors affecting drug action norma nicholson ba, ma. 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. Home medical reference and training manuals factors affecting drug action drug dosage and theraphy. Factors affecting distribution of drug tissue permeability of drug 1. 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. Technological advancements in the area of matrix formulation have made controlledrelease product development. 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. Factors affecting drug abuse in adolescent females in rural. Decreasing drug absorption from git due to mucosal edema and splanhnic vasoconstriction. Clinical pharmacokinetics is the application of pharmacokinetic principles to the safe and effective therapeutic management of drugs in an individual patient.
What are the factors affecting the dose and action of drugs. Psychological factors in drugtaking behavior video. As a member, youll also get unlimited access to over 79,000 lessons in math, english, science, history, and more. For example, a large person generally needs more of a drug than a smaller person needs for the same effect. Chloroform and carbon tetrachloride become toxic if kept for long durations.
Factors affecting drug absorption and distribution. Variations government medical college and hospital. Adolescent drug abuse is a phenomenon which is determined by multiple factors. To discuss the effect of certain factors on the occurrence of adverse drug reactions adrs. This process is more complex if the person takes other drugs and has other diseases, because drug drug and drug disease interactions are possible. Factors affecting drug treatment compliance in patients with rheumatoid arthritis. Factors affecting the development of adverse drug reactions. The main objective of this study was to investigate environmental and demographic factors influencing drug and substance abuse among secondary school students in kisumu town east, kenya. Overview of factors affecting oral drug absorption naining song a,b, shaoy u zhang b, changxiao liu a a tianjin state key laboratory of pharmacokinetics and pharmaco dynamics, tianjin inst.
Factors affecting mechanism and kinetics of drug release from. Concentrating the initial drug load in fem into non uniformly distributed drug regions inside the matrix created drug release profiles that more closely resembled experimental data than an femsimulated uniform drug distribution did. Quizlet flashcards, activities and games help you improve your grades. Factors affecting drug action cont drug dosage and theraphy. One of the most important factors that would affect drug effects are those that result from simultaneous use of two or more drugs in therapeutic practice. Sep 22, 2017 a powerpoint presentation of undergraduate level pharmacology on factors modifying drug action slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Whether people take a drug as instructed adherence also affects their response to it. Dec 09, 2015 class factors modifying drug action 1. As the drug concentration goes down, the percentage of time the receptor is occupied also decreases. Plus, get practice tests, quizzes, and personalized coaching to help you succeed. The contact between the enzyme and substrate is the most essential prerequisite. We document compliance with drug treatment and the factors affecting it in a cohort of patients. Pdf factors affecting drug treatment compliance in patients. Factors affecting drug action drug dosage and theraphy.
Factors affecting drug absorption and distribution request pdf. The speed with which drugs move in and out of the body varies widely among different people. Pdf overview of factors affecting oral drug absorption. Another, and much larger, impact on the medicare part b reimbursement received by health care providers has been the shift from branded drugs to generic drugs. In general, children require smaller doses than adults. The drugs are present in free or bound form and different processes or mechanisms affect their distribution. These unique features may dictate when to treat and for how long. Factors influencing drug selection different seizure types and different types of epilepsy have different natural histories i.
Many factors can affect a drug s absorption, distribution, metabolism, excretion, and ultimate effect. For example, between 2002 and 20, while the overall market for sterile injectable drugs increased by 39 percent, the number of units sold by generic drug manufacturers increased by 57 percent. When a doctor prescribes you a pill or injects you with a medication in the hospital, it may seem like a really simple thing to an outsider. Drug s efficacy can be affected by patients expectations and attitude. S and warfarin are metabolized by two different cytochrome p450 isozymes. Overview of response to drugs msd manual consumer version. Outdated tetracyclines give rise to excretion of amino acids in urine.
Factors modifying drug effect and dosage pharmacodynamics. Route determines the speed and intensity of drug response parenteral for speedy action. They may also affect choice of medication, since some drugs are effective against specific seizures and syndromes. This variance of drug action may be due to a number of factors not inherent in the drug itself. Normal bodily functions also vary with the time of day, thus affecting drug action. In order to discuss this topic, the factors affecting drug metabolism will be split into internal i. Drugs that either inhibit or induce these enzymes can significantly affect warfarins anticoagulation activity. The researchers interest in the study evolved from her involvement with adolescent drug patients at magaliesoord centre. Factors influencing drug selection epilepsy foundation. Aug 20, 2012 matrix technologies have often proven popular among the oral controlled drug delivery technologies because of their simplicity, ease in manufacturing, high level of reproducibility, stability of the raw materials and dosage form, and ease of scaleup and process validation. In the administration of medicines there are many factors that affect the dose, method of administration, and frequency of the dose.
Factors affecting drug action flashcards from mandy d. Technological advancements in the area of matrix formulation have made controlledrelease product development much easier. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Many factors can affect a drugs absorption, distribution, metabolism, excretion, and ultimate effect. Firstpass refers to orally administered drugs that are extensively metabolized as they pass through the liver see chapter 3. A drug may have different actions via different routes magnesium sulfate 7. Action may be modified if kept for longer durations. Family and peer behaviour and standards are for most youth the greatest sources of influence. Factors affecting mechanism and kinetics of drug release. Smt kishoritai bhoyar college of pharmacy, kamptee. The time for drug distribution is generally measured by the distribution halflife or the time for 50% distribution. These factors are imbedded in the cultural and social structures within communities. A powerpoint presentation of undergraduate level pharmacology on factors modifying drug action slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.
Factors affecting drug action study guide by brandib629 includes 30 questions covering vocabulary, terms and more. Mar 10, 2020 steric features of drugs last updated on tue, 10 mar 2020 pharmaceutical chemistry regardless of the ultimate mechanism by which the drug and the receptor interact, the drug must approach the receptor and fit closely to its surface. But naturallyoccurring substances can also have adverse effects, as can the food additives of today. Introduction to pharmacokinetics and pharmacodynamics. These factors may affect how the body absorbs the drug, how the body breaks down metabolizes and eliminates the drug, or what effects the drug has. The specific effect which drugs exert on certain organs may be altered in both intensity and rate of appearance and disappearance. Since the brain is a highly perfused organ, following i. Alteration in concentration of drug that reaches the receptorage, weight, sex, disease states, mdrmulti drug resistance genes 2. Ph, solubility, ionization affecting absorption pharmatutor. The consequences of drug abuse are vast and varied and affect people of all ages.
The process by which a drug reversibly leaves the blood stream and enters the interstitium extracellular fluid andor the cells or tissues. Seeing drug dealers in your neighborhood can be scary, but you can get rid of them by watching for suspicious activity, like excessive loitering around a certain house or odd smells, and reporting it to the police as soon as possible. Unlike previous studies on substance use which focused almost. Certain combinations of drugs can slow down or speed up the effects. If drug distribution is limited by the slow diffusion of the drug across the membrane in the tissue, then the process is termed as diffusion or permeability limited. One drug may alter the dose or the effect s of another drug when the two are used concurrently, these are called drug interactions consequences of such interactions are. Although alcoholism and addiction are clinical diseases that can affect any person from any race, occupation or location, there are a number of social and economic factors that statistically may place certain groups of people at higher risk of addiction than others. Other obvious examples include nicotine and tetrahydrocannabinol thc, which are absorbed following inhalation of tobacco or marijuana smoke. The greater the drug concentration at a receptor zone, the more likely it is that a drug molecule will be occupying the receptor site at any given time. Matrix technologies have often proven popular among the oral controlled drug delivery technologies because of their simplicity, ease in manufacturing, high level of reproducibility, stability of the raw materials and dosage form, and ease of scaleup and process validation. Home medical reference and training manuals factors affecting drug action cont drug dosage and theraphy factors affecting drug action drug dosage and theraphy section ii.
Drug abuse is recognised as one of the greatest social problems in south africa. There are additional changes that alter the activity of the drug at the site of action. Factors affecting drug action at texas womens university. Metastable polymorphs exhibit greater dissolution and hence better absorption and therapeutic activity than stable polymorphs. Drugs, brains, and behavior the science of addiction image. Factors affecting drug abuse in adolescent females in. Foods containing biochemically active substances have been used therapeutically throughout the ages and continue to function as important adjuncts to drug therapy. The findings of the study would be used to guide policy in the control and. The plasma and the ecf volume also increase but there is a fall in albumin content. Beware this talk will make you rethink your entire life and work life changer duration. Thiopental a lipophilic drug has a high tissueblood partition coefficient towards the brain and still higher for adipose tissue. Drugs, brains, and behavior the science of addiction. Inhalation volatile anesthetics, as well as many drugs which affect pulmonary function, are administered as aerosols.
Drugs directly affect many parts of the brain, which can cause problems with learning, sleeping, and emotional health. Over time, drug abuse can change the brains wiring and function, turning a voluntary behavior trying drugs into a compulsive one not being able to stop using drugs that defines addiction. Physicochemical parameters affecting drug action dr. Some drugs shows polymorphism steroids, barbiturates, they are not chemically different, but different in physicochemical properties like m. For most drugs, i would say the answer is yes, but for many drugs there is no change. Onset of action is rapid when drug is given in liquid form. This article throws light upon the six factors affecting the enzyme activity. Adolescents in rural communities tend to use more alcohol and tobacco than other substances howard et al.