Introduction to Pharmacology .pptx

Introduction to Pharmacolog y BIO 3310: Human Physiology & Pharmacology Christine Verghese, MSN, APRN, FNP-BC Pharmacology and Drug Therapy Drugs: ○ A chemical that can affect human processes ○ Chemicals used for therapeutic purposes ○ Have local and systemic effects Pharmacology ○ st...

Introduction to Pharmacolog y BIO 3310: Human Physiology & Pharmacology Christine Verghese, MSN, APRN, FNP-BC Pharmacology and Drug Therapy Drugs: ○ A chemical that can affect human processes ○ Chemicals used for therapeutic purposes ○ Have local and systemic effects Pharmacology ○ study of chemical (drugs) that alter functions of living organisms ○ Clinical pharmacology is the study of drugs in humans Pharmacotherapy (drug therapy): ○ use of drugs to prevent, diagnose, or treat signs, symptoms, and disease processes 2 Drug Sources Plants Animals Older sources Minerals Biotechnology Newer sources Synthetic 3 List 4 Properties of an Ideal Drug 1. Effectiveness 2. Safety 3. Selectivity 4. Convenience Other Considerations Minimal Interactions Frequency of dose Low Cost Chemical Stability Simple generic name Reversibility Predictability Ease of administration Is there an ”ideal drug”? What is the Therapeutic Objective for Drug Therapy? 7 Provide maximum ____________________ with minimum ____________________. Types of Drug Chemical Names oN-acetyl-para-aminophenol Generic (nonproprietary) oacetaminophen Trade/Brand (proprietary)---Capitalized oTylenol 8 Copyright © 2025 Wolters Kluwer. All rights reserved. Generic vs Trade? Bioavailability Bioequivalent Biosimilar  Amicar Amikin Omacar Examples of Drugs with Inderal Allerall Sound Alike Lamictal Lamisil Lomotil Names Lodine Iodine Nicoderm Nitroderm Renagel Remegel Tamiflu Theraflu 10 Copyright © 2025 Wolters Kluwer. All rights reserved. Drug Classifications Chemical Characteristics ○ Based on how the chemicals work in the body Benzodiazepines Cephalosporins Therapeutic Classifications ○ Based on what the drug does clinically (often have “anti” in them) Anticoagulants Antidepressants Antineoplastics Pharmacologic Classifications/Chemical Action ○ Based on how the drug produces its effect on the body Diuretic Calcium channel blocker 11 Prototypes A drug that is most used or representative of a category of drug. ○ Often the first drug of a particular group to be developed ○ Morphine (represents opioid analgesics) ○ Penicillin (represents beta-lactam antibacterial drugs) Allows you to remember easier: It is impossible to know everything about every drug! Drugs in a category act similarly and share the same ○ Therapeutic effect ○ Side/adverse effects ○ Contraindications/precautions ○ Administration considerations 12 10 Rights of Med Administration 1. Right drug 2. Right dose 3. Right patient 4. Right route 5. Right time 6. Right reason 7. Right documentation 8. Right teaching 9. Right evaluation 10.Right to refuse Nursing Responsibilities Regarding Drug Administration Follow “rights” consistently. Learn essential information about medications to be given. Interpret the prescriber’s orders accurately. ○ Write down or enter into computer and read back verbal or phone orders. Read medication labels carefully. Use only approved abbreviations use to prevent errors. Calculate doses accurately. Measure doses accurately. Use correct procedures and techniques for all administration routes. Learn about the patient’s diagnoses and condition in relation to medication administration. 14 Nursing Responsibilities Regarding Drug Administration (cont’d) Verify identity of all patients before administering medications. Omit or delay doses as indicated by the patient’s condition and document accordingly. Be especially careful when administering medication to children due to high risk of medication error. Maintain up-to-date drug administration skills and knowledge. 15 Monitoring Drug Safety IOM: Institute of Medicine report QSEN: Quality and Safety Education for Nurses ○ “Do Not Use” List list of unacceptable abbreviations ○ FDA ----monitor drugs on the market ○ Drug testing protocols Investigational Drug Studies Phase 1, Phase 2, Phase 3 clinical trials-----approval Phase 4: Post-Marketing Surveillance Ways to prescribe ○ OTC ○ Prescriptions Review of Laws ○ ISTOP in NYS DEA Schedules of Controlled Substances Schedule I - High abuse, no medical use i.e. Heroin Schedule II - High abuse, severe dependence liability i.e. opioid analgesics Schedule III - Less abuse, moderate dependence liability i.e. Phenobarbital, Zoloft Schedule IV - Less abuse , limited dependence liability i.e. Benzodiazapam Schedule V - Limited abuse potential i.e. Lomotil, cough meds 17 Cellular Physiology Cells are dynamic “factories” that ○ Take in raw materials ○ Manufacture products required to maintain bodily functions ○ Deliver those manufactured products to the appropriate destination within the body ○ Differ from one tissue to another Cells can ○ Exchange materials with immediate environment ○ Obtain energy from nutrients ○ Reproduce ○ Communicate with one another via biologic chemicals 18 Cellular Physiology 19 Copyright © 2025 Wolters Kluwer. All rights reserved. Importance of the Cell Membrane Review: ○ Cell membranes include the following Phospholipid, Proteins, Cholesterol, Carbohydrates Have receptor sites ○ Double lipid layer with embedded proteins ○ Proteins: Create structural pores for transport Are carriers Act to regulate intracellular function (enzymes) Pharmacokinetics & Drug Transport Pathways Definition: Study of drug movement throughout the body. How do drugs cross cell membranes? ○ Direct penetration: must be lipid soluble to pass through ○ Through pores/channels: used by small ions, Na and K. ○ By transport system: carrier proteins (are selective) based on chemical structure (P-glycoprotein)  4 Pharmacokinetic Processes 2. 3. 4. 1. Absorption Distribution Metabolism Excretion via the blood to the cells removal from the From the site biotransformation body Pharmacokinetic Process Absorption Absorption process ○ Occurs from time drug enters body to time it enters bloodstream to be circulated ○ Onset of drug action is largely determined by the rate of absorption. What is bioavailability? ○ amount of drug available after passing through the liver. 24 Factors Affecting Drug Absorption Rate of dissolution Dosage & route of administration Administration site blood flow, GI function Enzymes present Surface area Blood flow Lipid solubility pH partitioning/ion trapping Other food/drugs present in the system Routes of Administration Oral (by mouth) Parenteral (injected) Subcutaneous (Sub-Q) Intramuscular (IM) Sub-Q Injection Sites Intravenous (IV) Topical (applied to skin or mucous membrane) 27 IM Injection Sites: deltoid, ventrogluteal and vastus lateralis Types of Oral Medications by Rates of Absorption Fastest Immediate Release Liquid Suspension Powder Capsules Tablets Enteric Coated (EC) Sustained Release (SR or XR) Sustained Action (SA) Extended Release (ER) Slowest Advantages/Disadvantages of Administration Routes ADVANTAGES DISADVANTAGES IV Quick Expensive Good control over levels Can’t self administer Use of lg fluid vol. Difficult to reverse Use of irritating drugs ↑ risks (infection, embolism, fluid overload) IM/SQ Only barrier is capillary wall Inconvenient For poorly soluble drugs Uncomfortable Use of depot preparations PO Easy Variable absorption Convenient Inactivated by 1st pass Inexpensive Requires compliance Local irritation possible Distribution Distribution process  Transport of drug molecules within body Major factors affecting drug distribution: Blood flow to tissues Ability of drug to exit vascular system Ability of a drug to enter cells 30 Explain How Blood brain barrier Drugs Exiting Bloodstream into Placental transfer of drugs Tissue are Affected by: Protein binding (Bound vs Free drugs) Bound drug is inactive Free drug is active 31 Copyright © 2025 Wolters Kluwer. All rights reserved. 32 3 4 Entering Cells Some drugs must enter cells to reach the site of action Most drugs must enter cells to undergo metabolism and excretion Many drugs produce their effects by binding with receptors on the external surface of the cell membrane ○ These do not need to cross the cell membrane to act Metabolism AKA Biotransformation Metabolic process (biotransformation): ○ Method by which drugs are altered from their original form into a new form (biotransformed) by the body ○ Drugs changed to Inactive metabolites (excreted) Active metabolites Prodrugs (exert effects when metabolized) (can be more or less potent) Most drug metabolism takes place in the _____________________. What is first pass? 35 First Pass  Accelerated renal excretion Describe Consequences of Inactivation of drug Metabolism Increased therapeutic action (the P450 System Pro-drug activation in the liver) Increased/decreased toxicity 38 Copyright © 2025 Wolters Kluwer. All rights reserved. Excretion The most important organ for drug excretion is the __________________. Other ways drugs are excreted? Describe the excretion processes: ○ Glomerular filtration ○ Passive tubular reabsorption ○ Active tubular secretion 39 Renal Drug Excretion Define Terms Related to Serum Drug Levels Minimum effective concentration (MEC) must be present for efficacy. Toxic concentration: excessive level of medication in bloodstream; caused by Single large dose Repeated small doses Slow metabolism of medication Therapeutic range  Define Terms related to Regulation of Drug Response Onset of Action/Duration Half life Plateau of Action Peak and trough Loading dose Maintenance dose  Pharmacodynamics  Definition: study of the biochemical and physiologic effects of drugs and the mechanism by which effects are produced. Dose Response Curve Pharmacodynamic terms: ○ Potency Amount of a drug needed to see the effect ○ Efficacy The effect a drug can have (i.e. pain relief) 46 Therapeutic Index Definition: Measure of a drug’s safety (the lower the number, the less safe!) The greater the average lethal dose compared to its therapeutic dose, the __________ the drug. If a drug’s average dose and therapeutic dose are close, then the drug is ______. Drugs and Receptors The general equation for the interaction between drugs and their receptors is as follows (where D = drug and R = receptor): D + R ⇌ D-R COMPLEX → RESPONSE Non-Receptor Drug Relatively few drugs do not act on receptor sites. These few drugs include ○ Antacids ○ Osmotic diuretics ○ Several anticancer drugs ○ Drugs that are structurally similar to nutrients used by cells ○ Metal chelating agents 50  Agonist Discuss these Drug-Drug Interactions Partial Agonist Antagonist ***Very rarely does a drug cause a new reaction, it mainly “turns on” or “turns off” a response (increases or decreases cell function) 51 Copyright © 2025 Wolters Kluwer. All rights reserved. Discuss these Drug-Drug Interactions Additive: 1 + 1 = 2 (agonist) Synergistic: 1 + 1 = >2 (agonist) Inhibitory: 1 + 1 = < 2 (often 0) (antagonist) Creation of new response Consequences of Drug-Drug Interactions 54 Intensification of effects Increased therapeutic effects Increased adverse effects Reduction of effects Reduced therapeutic effects Reduced adverse effects Creation of a unique response Drug-Drug Interactions 56 Minimizing Adverse Drug-Drug Interactions Minimize the number of drugs a patient receives Take a thorough drug history Be aware of the possibility of illicit drug use Adjust the dosage when metabolizing inducers are added or deleted Adjust the timing of administration to minimize interference with absorption Monitor the patient for early signs of toxicity Be especially vigilant when a patient is taking a drug with a low therapeutic index Organ Specific Toxicity Bone Marrow Toxicity Cardiotoxicity ○ QT prolongation-Torsades de Pointe Dermatologic Toxicity ○ Rashes ○ Angioedema ○ Steven’s Johnson Syndrome Hepatotoxicity Nephrotoxicity Neurotoxicity Ototoxicity Skeletal Muscle/Tendon Toxicity You Must Know these….. Please be familiar with the terms and concepts on the following slides. You will be responsible for them on the Module 1 exam. Understand the following….. Side Effect vs Adverse Effect Precautions Contraindications Define These Adverse Drug Reactions: Toxicity Allergic reaction Idiosyncratic effect Iatrogenic disease Physical dependence ○ Withdrawal ○ Addiction Carcinogenic effect Teratogenic effect Hepatotoxicity QT interval prolongation Tolerance  Definition  Define kinds of tolerance:  Pharmacodynamic  Metabolic  Tachyphylaxis Describe the Impact of Food Interactions on: Drug absorption Drug toxicity Drug metabolism What juice inhibits metabolism of certain drugs? Discuss Factors for Individual Variations to Drugs Age/gender/race Kidney/liver disease Acid-base imbalance Altered electrolytes Placebo effect Absorption Nonadherence Drug interactions Diet Special Populations/Considerations Pediatrics Patients Pregnant/Nursing Mothers Geriatric Patients Ethnic Considerations Giving Drugs in Pregnancy Physiological changes during pregnancy may require drug doses to be ________or ________. Decreased GI motility causes increased absorption and a need to decrease dosages Increase in plasma volume causes a decrease in the concentration of meds. Increased metabolism by the liver may cause a need to increase the dose. Increased renal blood flow and renal clearance may cause a need to increase the dose. Drugs During Pregnancy Less Predictable Cross Maternal-Placental-Fetal Circulation Effect the Fetus Need a Risk/Benefit analysis before administering any medication whether herbal, OTC or prescription Avoid drugs if possible, this includes alcohol, caffeine, cigarettes and herbal supplements Some vaccines may be beneficial (i.e. influenza) Fetal Therapeutics Some medications are administered to the mother to treat the fetus. ○ Digoxin (fetal tachycardia or heart failure) ○ Levothyroxine (hypothyroidism) ○ Penicillin (exposure to maternal syphilis and group B Streptococcus [GBS]) ○ Corticosteroids (promote surfactant production to decrease respiratory distress syndrome in preterm infants) 67 Teratogenesis Gross malformations can result from drug exposure during what trimester of pregnancy? Disruption of function (vs. malformation of anatomy) can occur during the _________& __________ trimester of pregnancy. Explain why teratogens are difficult to identify 69 Describe the FDA Pregnancy Risk Categories CATEGORY DEFINITION IMPLICATION FOR NURSING Studies in pregnant women have not shown any risk to the fetus Drugs in this category are considered safe during the first trimester or later trimesters. to use during pregnancy. A Animal studies have not shown a risk to the fetus, but there are no Generally considered safe, but caution is well-controlled studies in pregnant women; or animal studies advised. B showed a risk that wasn’t confirmed in human studies. Animal studies have shown an adverse effect on the fetus, but there These drugs should be used only if the are no well-controlled studies in humans; potential benefits may potential benefit justifies the potential risk C warrant use despite risks. to the fetus. There is evidence of human fetal risk based on adverse reaction These drugs carry significant risks; they data, but potential benefits may warrant use in pregnant women should be used during pregnancy only in D despite these risks. life-threatening situations or serious disease where safer drugs cannot be used or are ineffective. Studies in animals or humans have demonstrated fetal These drugs are contraindicated in abnormalities, or there is evidence of fetal risk based on human pregnancy and should never be used by X experience, and the risks clearly outweigh any potential benefits. pregnant women or women who may become pregnant. Taking Drugs When Breastfeeding Do most drugs enter breast milk? If drug concentrations in milk are high enough, what can happen to infant? How can breastfeeding women minimize risks when taking drugs? Pediatric Pharmacokinetics Due to organ immaturity ○ Younger the child the greater the variation Due to differences in body concentration (H2O, fat stores, number of proteins) Drug effects in infants are unusually increased and prolonged. What causes free concentrations of some drugs to be high in infants? Why are neonates especially sensitive to drugs affecting CNS? How do children ages 1-12 differ pharmacokinetically from adults? Causes of Drugs Variations in Pediatric Patients Delayed, irregular gastric emptying Decreased acidity in the stomach Decreased blood flow to muscles Increased skin permeability Higher percentage of body water (80%) Immature liver and kidney function Fewer proteins (thus less protein binding) Poorly developed blood-brain barrier Causes of Variations in Geriatric Patients The rate of drug absorption may be slowed. Drug effects can be prolonged with reduced liver function. What is the most important cause of adverse drug reactions in the elderly? Decreased number of receptor site and changes in the affinity at those sites Decreased sensory perception effect's ability to correctly administer meds. Issues of polypharmacy, antibiotic resistance and increased sensitivity to meds  Medications that need to be given with care to Beers Criteria for geriatric patients created by American Elderly Patients Geriatrics Society (AGS) For more information: http://www.americangeriatrics.org/files/docume nts/beers/BeersCriteriaPublicTranslation.pdf 75 Copyright © 2025 Wolters Kluwer. All rights reserved. Geriatric Drug Concerns Are adverse drug reactions in the elderly more or less common than in younger adults? ○ Why? What are causes for unintentional nonadherence? How common is intentional nonadherence? ○ What are reasons for it? 77 Predisposing ADR Factors Drug accumulation secondary to reduced renal function Polypharmacy Greater severity of illness Multiple pathologies Greater use of drugs that have a low therapeutic index (for example, digoxin) Increased individual variations secondary to altered pharmacokinetics Inadequate supervision of long-term therapy Poor patient adherence 78 Promoting Adherence with Unintentional Nonadherence Simplified drug regimens Clear and concise verbal and written instructions Appropriate dosage form Clearly labeled and easy-to-open containers Daily reminders Support system Frequent monitoring Holistic Approach to Pharmacology Each person is an integrated biological, psychosocial, cultural, communicating and unique person. As such, drug treatment needs to be individualized. There is no “one regime treats all”  Age Take into Consideration Genetics Biologic characteristics Personal habits (ie diet) Lifestyle Environment Belief systems Alternative therapies Previous experiences 80 Copyright © 2025 Wolters Kluwer. All rights reserved. Cultural Considerations Socioeconomic levels Literacy Genetic polymorphisms (pharmacogenetics/pharmacogenomics) Spiritual/Religious beliefs Gender behavior differences