Chapter 2 Basic Concepts and Processes PDF

Chapter 2 Basic Concepts and Processes  Cells are dynamic “factories” that Cellular oTake in raw materials Physiology #1 oManufacture products required to maintain bodily functions oDeliver those manufactured produ...

Chapter 2 Basic Concepts and Processes  Cells are dynamic “factories” that Cellular oTake in raw materials Physiology #1 oManufacture products required to maintain bodily functions oDeliver those manufactured products to the appropriate destination within the body oDiffer from one tissue to another 2 Copyright © 2025 Wolters Kluwer. All rights reserved. Cellular Physiology #2 3 Copyright © 2025 Wolters Kluwer. All rights reserved.  Is the following statement True or False? Question #1 While all cells differ from one tissue to another, they share certain common characteristics. 4 Copyright © 2025 Wolters Kluwer. All rights reserved.  True Answer to Question #1 Rationale: While all cells differ from one tissue to another, they share common characteristics, including the ability to exchange materials from their immediate environment, obtain energy from nutrients, synthesize complex molecules, reproduce, and communicate with one another via biologic chemicals. 5 Copyright © 2025 Wolters Kluwer. All rights reserved.  Cells can Cellular oExchange materials with immediate Physiology #3 environment oObtain energy from nutrients oReproduce oCommunicate with one another via biologic chemicals 6 Copyright © 2025 Wolters Kluwer. All rights reserved.  Drugs must reach and interact with or cross Drug Transport the cell membrane to stimulate or inhibit Through Cell cellular function. Membranes #1 Most drugs are given for systemic effect. Transport pathways and mechanisms move drug molecules through the body. 7 Copyright © 2025 Wolters Kluwer. All rights reserved. Drug Transport Through Cell Membranes #2 8 Copyright © 2025 Wolters Kluwer. All rights reserved.  Define pharmacokinetics. Pharmacokinetics oDrug movement through the body Specific processes involved oAbsorption oDistribution oMetabolism oExcretion 9 Copyright © 2025 Wolters Kluwer. All rights reserved.  Absorption process Absorption oOccurs from time drug enters body to time it enters bloodstream to be circulated oOnset of drug action is largely determined by the rate of absorption. oFactors that affect rate and extent of drug absorption Dosage form, route of administration Administration site blood flow, GI function The presence of food or other drugs 10 Copyright © 2025 Wolters Kluwer. All rights reserved.  Distribution process Distribution #1 oTransport of drug molecules within body oDrugs are carried by blood and tissue fluids to Action sites Metabolism sites Excretion sites oDepends largely on adequacy of blood circulation 11 Copyright © 2025 Wolters Kluwer. All rights reserved.  Distribution process affected by Distribution #2 oProtein binding oBlood–brain barrier oPregnancy oLactation 12 Copyright © 2025 Wolters Kluwer. All rights reserved.  Metabolic process (biotransformation): Metabolism #1 oMethod by which drugs are altered from their original form into a new form (biotransformed) by the body oDrugs changed to Inactive metabolites (excreted) Active metabolites Prodrugs (exert effects when metabolized) 13 Copyright © 2025 Wolters Kluwer. All rights reserved.  Drug-metabolizing enzymes are located within Metabolism #2 oKidneys oLiver oRed blood cells, plasma oLungs oGastrointestinal mucosa 14 Copyright © 2025 Wolters Kluwer. All rights reserved.  Factors that affect drug metabolism Metabolism #3 oEnzyme induction (accelerates) oEnzyme inhibition (decreased or delayed) 15 Copyright © 2025 Wolters Kluwer. All rights reserved.  Excretion Excretion oElimination of a medication from the body oRequires adequate function of Circulatory system Organs of excretion (kidneys, bowel, lungs, and skin) 16 Copyright © 2025 Wolters Kluwer. All rights reserved.  Is the following statement True or False? Question #2 Absorption is the transport of drug molecules within the body. 17 Copyright © 2025 Wolters Kluwer. All rights reserved.  False Answer to Question #2 Rationale: Distribution is the transport of drug molecules within the body. Absorption is the process that occurs from the time a drug enters the body to the time it enters the bloodstream to be circulated. 18 Copyright © 2025 Wolters Kluwer. All rights reserved.  Serum drug level Serum Drug Level oLaboratory measurement of the amount of a #1 drug in the blood at a particular time oReflects Dosage Absorption Bioavailability Half-life Rates of metabolism Excretion 19 Copyright © 2025 Wolters Kluwer. All rights reserved.  Minimum effective concentration (MEC) must Serum Drug Level be present for efficacy. #2 Toxic concentration: excessive level of medication in bloodstream; caused by oSingle large dose oRepeated small doses oSlow metabolism of medication 20 Copyright © 2025 Wolters Kluwer. All rights reserved.  Drugs exert their effects by chemically Receptor Theory binding with receptor cells through: of Drug Action oActivation, inactivation, or alteration of intracellular enzymes oChanges in the permeability of cell membranes to one or more ions oModification of the synthesis, release, or inactivation of neurohormones oAgonists and antagonist drugs 21 Copyright © 2025 Wolters Kluwer. All rights reserved.  Relatively few drugs do not act on receptor Nonreceptor Drug sites. These few drugs include Actions oAntacids oOsmotic diuretics oSeveral anticancer drugs oMetal chelating agents 22 Copyright © 2025 Wolters Kluwer. All rights reserved.  Dosage Drug-Related oFrequency, size, number of doses Variables #1 Route of administration oInfluences absorption and distribution Drug–diet interactions Drug–drug interactions 23 Copyright © 2025 Wolters Kluwer. All rights reserved.  Interactions that can increase therapeutic or Drug-Related adverse effects include Variables #2 oAdditive effects oSynergism oInterference oDisplacement 24 Copyright © 2025 Wolters Kluwer. All rights reserved.  Interactions in which drug effects are Drug-Related decreased include Variables #3 oAntidote medication oDecreased intestinal absorption of drugs oIncreased metabolism rate of drugs 25 Copyright © 2025 Wolters Kluwer. All rights reserved.  Age, body weight Patient-Related Pharmacogenomics, genetics, ethnicity, Variables gender Pharmacogenetics Preexisting pathologic conditions Psychological considerations Tolerance and cross-tolerance 26 Copyright © 2025 Wolters Kluwer. All rights reserved.  Adverse effects Adverse Effects of oAny undesired responses to medication Drugs administration All drugs can produce adverse effects. Can occur with usual therapeutic dosing More likely to occur or be more severe with high dosing Especially likely to occur with specific drugs and in older adults who take multiple drugs Boxed warnings, pregnancy categories 27 Copyright © 2025 Wolters Kluwer. All rights reserved.  Also called poisoning or overdose Toxicology: Drug Overdose #1 Results from excessive amounts of medication May damage body tissues Common problem in both adult and pediatric populations 28 Copyright © 2025 Wolters Kluwer. All rights reserved.  May result from Toxicology: Drug oSingle large dose Overdose #2 oProlonged ingestion of smaller doses May involve alcohol, prescription, OTC, or illicit drugs Can be a medical emergency, regardless of location 29 Copyright © 2025 Wolters Kluwer. All rights reserved.  Main goals of treatment Toxicology: Drug oStarting treatment soon after ingestion Overdose #3 oSupporting and stabilizing vital function oPreventing further damage by Reducing absorption Increasing elimination Administering antidotes whenever possible 30 Copyright © 2025 Wolters Kluwer. All rights reserved.