PHARMA - PRELIM REVIEWER.pdf

WEEK 01: FUNDAMENTAL CONCEPT OF Dissolution - The process by which solid forms of drugs PHARMACOLOGY disintegrate in the gastrointestinal tract and become s...

WEEK 01: FUNDAMENTAL CONCEPT OF Dissolution - The process by which solid forms of drugs PHARMACOLOGY disintegrate in the gastrointestinal tract and become soluble before being absorbed into the circulation Pharmacology - It also includes history, source, physicochemical Drug classification - A method of grouping drugs; may properties, dosage forms, methods of be based on structure or therapeutic use administration, absorption, distribution mechanism of action Drug-induced teratogenesis - The development of - is the study of interaction of drugs with living congenital anomalies or defects in the developing fetus organisms caused by the toxic effects of drugs - It is also biotransformation, excretion, clinical uses and adverse effects of drugs Drug effects - The physiologic reactions of the body to a drug. They can be therapeutic or toxic and describe how Pharmaco- "drug" or "medicine." the body is affected as a whole by the drug Other means: - The terms onset, peak, and duration are used to - dynamics describe drug effects (most often referring to therapeutic - genomics effects - gnosy - kinetics Drug interaction - Alteration in the pharmacologic or pharmacokinetic activity of a given drug caused by the Prescriber - Any health care professional licensed by presence of one or more additional drugs; it is usually the appropriate regulatory board to prescribe related to effects on the enzymes required for medications metabolism of the involved drugs Prescriber must be checked for the following six Duration of action - The length of time the elements: concentration of a drug in the blood or tissues is patient's name sufficient to elicit a response date the drug order was written name of drug(s) First-pass effect - The initial metabolism in the liver of a drug dosage amount and frequency route of drug absorbed from the gastrointestinal tract before the administration drug reaches systemic circulation through the prescriber's signature bloodstream Medication error - Any preventable adverse drug event Generic name - Also called the nonproprietary name involving inappropriate medication use by a patient or - is much shorter and simpler than the chemical name health care professional; it may or may not cause the and is not protected by trademark patient harm Half-life - In pharmacokinetics, the time required for half Adverse effects - A general term for any undesirable of an administered dose of drug to be eliminated by the effects that are a direct response to one or more drugs body, or the time it takes for the blood level of a drug to be reduced by 50% (also called elimination half-life Allergic reaction - An immunologic hypersensitivity reaction resulting from the unusual sensitivity of a patient Idiosyncratic reaction - An abnormal and unexpected to a particular medication; a type of adverse drug event response to a medication, other than an allergic reaction, that is peculiar to an individual patient Additive effects - Drug interactions in which the effect of a combination of two or more drugs with similar Intraarterial - Within an artery (e.g., intra arterial actions is equivalent to the sum of the individual effects injection) of the same drugs given alone Incompatibility - The characteristic that causes two Chemical name - The name that describes the chemical parenteral drugs or solutions to undergo a reaction when composition and molecular structure of a drug mixed or given together that results in the chemical deterioration of at least one of the drugs Blood-brain barrier - The barrier system that restricts the passage of various chemicals and microscopic Intraarticular entities (e.g., bacteria, viruses) between the bloodstream - Within a joint and the central nervous system - (e.g., intraarticular injection) Contraindication - Any condition, especially one related Intrathecal - Within a sheath (e.g., the theca of the to a disease state or patient characteristic, including spinal cord, as in an intrathecal injection into the current or recent drug therapy, that renders a particular subarachnoid space) form of treatment improper or undesirable Medication use process - The prescribing, dispensing, Toxicity - condition of producing adverse bodily effects and administering of medications, and the monitoring of due to poisonous qualities their effects Pharmaceutics - is the study of how various dosage Metabolite - A chemical form of a drug that is the forms influence the way in which the drug affects the product of one or more biochemical (metabolic) body reactions involving the parent drug Pharmacognosy - study of these natural drug sources Onset of action - The time required for a drug to elicit a (plants and animals) therapeutic response after dosing Pharmacoeconomics - is the study of the economic Peak effect - The time required for a drug to reach its factors influencing the cost of drug therapy maximum therapeutic response in the body Drug Classification Peak level - The maximum concentration of a drug in Drugs can be classified by: the body after administration, usually measured in a a. Structure (e.g., beta-adrenergic blockers) blood sample for therapeutic drug monitoring. b. Therapeutic use (e.g., antibiotics, antihypertensives, antidepressants). Pharmacodynamics - The study of the biochemical and physiologic interactions of drugs at their sites of activity Drugs may be classified by a variety of methods - It examines the physicochemical properties of drugs according to: and their pharmacological interactions with body 1. The Body system that they affect (CNS, CVS, GI receptors system) 2. Their Therapeutic use or clinical indications (Antacids, Pharmacokinetics - The study of what happens to a antacids, antibiotics, antihypertensives, diuretics, drug from the time it is put into the body until the parent laxatives) drug and all metabolites have left the body 3. Their Physiologic or chemical action (anticholinergics, beta- adrenergic blockers, calcium channel blockers, Pharmacology - The broadest term for the study or cholinergics) science of drugs Drugs may be further classified as: Pharmacotherapeutics - The treatment of pathologic 1. prescription or nonprescription conditions through the use of drug - require an order by a health professional who is licensed to prescribe drugs, such as a physician, a nurse Prodrug - An inactive drug dosage form that is practitioner, a physician assistant, a pharmacist, or a converted to an active metabolite by various biochemical dentist reactions once it is inside the body 2. Nonprescription or over-the-counter (OTC) - drugs are sold without a prescription in a pharmacy or Receptor - A molecular structure within or on the outer in the health section of department or grocery stores. surface of a cell 3. Illegal drugs - Sometimes called recreational drugs Steady state - The physiologic state in which the - Are drugs or chemical substances used for non amount of drug removed via elimination is equal to the therapeutic purposes amount of drug absorbed with each dose - These substances are obtained illegally or have not received approval for use by the FDA Synergistic effect - Drug interactions in which the effect of a combination of two or more drugs with similar actions is greater than the sum of the individual effects of the same drugs given alone. Therapeutic drug monitoring - The process of measuring drug levels to identify a patient's drug exposure and to allow adjustment of dosages with the goals of maximizing therapeutic effects and minimizing toxicity Therapeutic effect - The desired or intended effect of a particular medication Tolerance - Reduced response to a drug after prolonged use Toxic - The quality of being poisonous (i.e., injurious to health or dangerous to life)  - The generic name of a drug is assigned by the U.S. Adopted Name Council - With few exceptions, generic names are less complicated and easier to remember than chemical names - There is only one generic name for each drug 3. Trade Name / Proprietary name - A drug's trade name is assigned by the company marketing the drug - The name is usually selected to be short and Drug Standards and Information easy to remember - The trade name is sometimes called the Drugs are obtained from proprietary or product or brand name Minerals - A combination drug contains more than one - Liquid paraffin, magnesium sulfate active generic ingredient. This poses a problem - Magnesium trisilicate in trying to match one generic name with one - Kaolin product name Animals - The rule of thumb is that the active ingredients in - Insulin, thyroid extract a drug are described by their generic name - Heparin and antitoxin sera - The generic name of a drug is usually Plants lowercase, whereas the trade name is - Morphine, digoxin capitalized - atropine, castor oil ✓ Despite the fact that the dosages may be identical, Synthetic source drug formulations are not always the same - Aspirin, sulphonamides ✓ The two drugs may have different inert ingredients - Paracetamol ✓ The key to comparing brand-name drugs and their - zidovudine generic equivalents may lie in measuring the bioavailability of the two preparations Micro organisms ✓ Addiction refers to the overwhelming feeling that - Penicillin drives someone to use a drug repeatedly - streptomycin and many other antibiotics Genetic engineering Dependence - Human insulin - Physical dependence refers to an altered - human growth hormone physical condition caused by the adaptation of the nervous system to repeated drug use. Three basic areas of pharmacology - Psychological dependence Pharmaceutics Pharmacokinetics Pharmacodynamics Basic Type of Drug Names 1. Chemical Name - A chemical name is assigned using standard nomenclature established by the International Union of Pure and Applied Chemistry (IUPAC) - A drug has only one chemical name, which is sometimes helpful in predicting a substance's physical and chemical properties Not all drugs with an abuse potential are regulated Chemical - describes the drug's chemical composition or placed into schedules and molecular structure Examples are: ✓ Example: diazepam: 7-chloro-1,3-dihydro- - Tobacco 1-methyl-5-phenyl-2H- 1,4-benzodiazepin-2-one - Alcohol ✓ Example: lithium carbonate, calcium gluconate, and - Caffeine sodium chloride A teratogen - is a substance that has the potential to ✓ Drugs are sometimes classified by a portion of their cause a defect in an unborn child during pregnancy chemical structure, known as the chemical group name ✓ Examples are antibiotics such as the fluoroquinolones and cephalosporins ✓ Other common examples include the phenothiazines, thiazides, and benzodiazepines. 2. Generic Name / Nonproprietary name  Drugs Therapeutic Toxic Ranges Range Carbamazepine 6-12 mcg/ml >12-15 mcg/ml Phenytoin 10-20 mcg/ml >30 mcg/ml Graded Dose-Response Relationship and Therapeutic Response Dose Response - the relationship between the minimal versus the maximal amount of drug dose needed to produce the desired drug response LESSON 02: PHARMACODYNAMICS Onset, Peak, and Duration of Action Onset of action - Is the time it takes to reach the PHARMACODYNAMICS - The term pharmacodynamics minimum effective concentration (MEC) after a drug is comes from the root words pharmaco, which means administered. "medicine," and dynamics, which means "change." Peak action - occurs when the drug reaches its - The branch of pharmacology concerned with the highest blood or plasma concentration mechanisms of drug action and the relationships Duration of action - Is the length of time the drug has between drug concentration and responses in a pharmacologic effect the body - Pharmacodynamics is concerned with the - Some drugs produce effects in minutes, but others may mechanisms of drug action in living tissues take hours or days. ➡️ - A time-response curve evaluates three parameters of ➡️ ➡️ Pharmacodynamic Drug in Receptor drug action ➡️ Micro-environment Drug binds to receptor - Parameters by using T (time) with subscripts (e.g., TO, Receptor activation of cell signaling Physiologic T1, T2, T3). Response - The time-response curve evaluates of drug action Therapeutic Index and Drug Safety The Graded Dose-Response Relationship and TI - Therapeutic Index Therapeutic Response ED - Effective Dose LD - Lethal Dose Potency and Efficacy - A drug that is more potent will produce a therapeutic effect at a lower dose, compared Therapeutic Index (TI) - estimates the margin of safety with another drug in the same class of a drug through the use of a ratio that measures the effective (therapeutic) dose (ED) in 50% of people The second method used to compare drugs is called (ED50) and the lethal dose (LD) in 50% of people (LD50) efficacy, which is the magnitude of maximal response that can be produced from a particular drug. The closer the ratio is to 1, the greater the danger of toxicity. Which is more important to the success of TI = LD50 pharmacotherapy, potency or efficacy? ED50 Drugs usually work in one of four ways: - The therapeutic index measures the margin of 1. To replace or act as substitutes for missing chemicals safety of a drug. It is a ratio that measures the 2. To increase or stimulate certain cellular activities effective therapeutic dose and the lethal dose. 3. To depress or slow cellular activities - The ED50 is the dose required to produce a 4. To interfere with the functioning of foreign cells, such specific therapeutic response in 50% of a group as invading microorganisms or neoplasms (drugs that of patients. act in this way are called chemotherapeutic agents). Therapeutic Index and Drug Safety - The LD50 is the dose of drug that will be lethal in 50% of a group of Receptor Theory animals - Drugs act through receptors by binding to the Low Therapeutic Index - drug has a narrow margin of receptor to produce (initiate) a response or to safety, and the drug effect should be closely monitored block (prevent) a response. High Therapeutic Index - drug has a wide margin of - The activity of many drugs is determined by the safety and carries less risk of drug toxicity. ability of the drug to bind to a specific receptor Therapeutic Range (Therapeutic Window) - The concentration of drugs in plasma is the drug level There are four receptor families: between the minimum effective plasma concentration to 1. Kinase-linked receptors achieve the desired drug action and the minimum toxic 2. Ligand-gated ion channels concentration/toxic effect 3. G protein-coupled receptor systems Example: Anticonvulsants 4. Nuclear receptors Kinase-linked receptors - The ligand-binding domain Drug Action for drug binding is on the cell surface. The drug activates Four categories of drug action include: the enzyme (inside the cell), and a response is initiated. 1. Stimulation or depression 2. Replacement Ligand-gated ion channels - The channel spans the 3. Inhibition or killing of organisms cell membrane and, with this type of receptor, the 4. Irritation channel opens, allowing for the flow of ions into and out of the cells. The ions are primarily sodium and calcium. Drug Action - It stimulates the rate of cell activity or the G protein-coupled receptor systems secretion from a gland increases - There are three components to this receptor - It depresses the cell activity and function of a response: specific organ 1. The receptor - use as replacement drugs such as insulin 2. The G protein that binds with guanosine triphosphate replace essential body compounds (GTP), - It inhibit or kill organisms interfere with bacterial 3. The effector that is either an enzyme or an ion cell growth (e.g., penicillin exerts its bactericidal channel effects by blocking the synthesis of the bacterial ➡️ Receptor ➡️ G protein ➡️ Effect cell wall) Drug - It act as the mechanism of irritation (e.g., laxatives irritate the inner wall of the colon, thus Nuclear receptors - Found in the cell nucleus (not on increasing peristalsis and defecation) the surface) of the cell membrane. Activation of receptors through the transcription factors is prolonged. Peak and Trough Drug Levels With the first three receptor groups, activation of the receptors is rapid. Peak Drug Levels - Indicate the rate of absorption of the drug Types of Drug-Receptor Interactions - Is the highest plasma concentration of drug at a specific time AGONIST - A drug that produce a response Trough drug levels - For example, when the drug bethanechol - Indicate the rate of elimination of the drug (Urecholine) is administered, it binds to - Is the lowest plasma concentration of a drug, acetylcholine receptors in the autonomic and it measures the rate at which the drug is nervous system and produces the same actions eliminated as acetylcholine. Types of Drug Effects ANTAGONIST - Drugs that block a response Non specific drugs effects - For example, the drug atropine competes with - Are the drugs that affect various sites and have acetylcholine for specific receptors associated properties of nonspecificity with the autonomic nervous system Non selective drugs - Are the drugs that affect various receptors or ANTAGONIST - Functional antagonists inhibit the effects have properties of non selectivity of an agonist not by competing for a receptor but by changing pharmacokinetic factors. EXAMPLES: Types of Antagonists Competitive antagonists Noncompetitive antagonists - The relationships that occur between agonists and antagonists explain many of the drug-drug and drug-food interactions that occur in the body - Other drugs act to prevent the breakdown of natural chemicals that are stimulating the receptor site. For example, monoamine oxidase (MAO) inhibitors block the breakdown of norepinephrine by the enzyme MAO. - Drug-Enzyme Interactions. Drugs also can cause their effects by interfering with the enzyme systems that act as catalysts for various chemical reactions. Loading Dose - Is the large initial dose and a drug is Example: given to achieve a rapid minimum effective concentration For oral administration important liberation processes in the plasma. include the disintegration of tablets or the dissolving of Initial dose - Is a prescribed dosage per day as ordered soluble coatings of tablets and capsules. ✓ Dispersible aspirin - tablets typically contain several WEEK 03: PHARMACOKINETICS excipients: dried maize starch powder, sodium lauryl sulfate, lactose, sodium saccharin, anhydrous citric acid, Pharmacokinetics - Is the process of drug movement to calcium carbonate, povidone, isopropyl alcohol and achieve drug action. lactose (starch basic granules). The Five processes are: ✓ Two of these ingredients react with one another in 1. Liberation water: citric acid + calcium carbonate calcium citrate + 2. Absorption carbon dioxide + water 3. Distribution 4. Metabolism (or biotransformation) The effervescence as carbon dioxide gas is released 5. Excretion (or elimination) helps break up the tablets, releasing small particles of aspirin. The smaller the particles, the more quickly they Liberation dissolve and are absorbed ✓ is the first step in the process by which medication enters the body and liberates the active ingredient that Absorption has been administered. - is reduced if the villi are decreased in number ✓ The pharmaceutical drug must separate from the because of disease, drug effect, or the removal vehicle or the excipient that it was mixed with during of small intestine manufacture. - Is the movement of drug particles from the Gl ✓ Drug delivery systems (also called dosage forms) tract to body fluids by passive absorption, active are necessary to enable the effective, safe and reliable absorption, or pinocytosis. use of medicinal drugs. Most drugs are formulated into - Most oral drugs are absorbed into the surface tablets or other forms of medicine. A formulation is a area of the small intestine through the action of mixture, made to a specific recipe, of the active the extensive mucosal villi. medicinal drug and one or more inactive substances. These inactive substances are called excipients. Three major process of Absorption 1. Passive Absorption There are a number of reasons for using these 2. Active absorption inactive substances. They can be used, for example, 3. Pinocytosis to : ✓ increase the ease with which an active drug is Passive absorption - Occurs mostly by diffusion absorbed by the body (movement from higher concentration to lower ✓ 'dilute' very powerful drugs to enable convenient and concentration). With the process of diffusion, the drug accurate doses to be measured out does not require energy to move across the membrane ✓ control the release of the active drug over a period of time, e.g. controlled- release tablets Active absorption - Requires a carrier such as an enzyme or protein to move the drug against a concentration gradient. Liberation is the process in which a pharmaceutical - Energy is required for active absorption. substance is released from the formulation it is delivered - Has a dependent action, they have high energy in. This must occur before the drug can be absorbed into breaking of phosphate bonds so they can enter the the body. channel. Process of liberation into three steps: Pinocytosis - Is a process by which cells carry a drug ✓ Disintegration across their membrane by engulfing the drug particles ✓ Disaggregation into the cell membranes because of the large size they ✓ Dissolution wouldn't fit in the channel or pocket of a carrier protein. Releasing the active drug The Passage of Drugs Through Plasma Membranes Liberation describes the way that a drug is released from 1. Active Transport its administered form. There are various release types: Transport 1. Immediate - the medicine is formulated to release the 2. Diffusion - are drugs in larger molecules that will medicinal drug without delay pass with the help of carrier proteins. Moves from higher 2. Delayed - the medicine is formulated to release to lower concentration and it needs help from the carrier medicinal drug sometime after it is taken (usually orally) protein. 3. Extended - the medicine is formulated to make the drug available over an extended period, allowing a reduction in dosing frequency compared with immediate or delayed-release medicines Absorption of Medications Distribution - Absorption is the primary pharmacokinetic factor Is the process by which the drug becomes available to determining the length of time it takes a drug to body fluids and body tissues. produce its effect Drug distribution is influenced by blood flow, the drug's - In order for a drug to be absorbed it must affinity to the tissue, and the protein-binding effect dissolve - The rate of dissolution determines how quickly Protein Binding the drug disintegrates and disperses into simpler Are drugs distributed in the plasma, many are bound forms; therefore, drug formulation is an to varying degrees (percentages) with protein (primarily important factor of bioavailability albumin). - In some instances it is advantageous for a drug Drugs that are greater than 89% bound to protein are to disperse rapidly. In other cases, it is better for known as highly protein-bound drugs the drug to be released slowly where the effects Drugs that are 61% to 89% bound to protein are are more prolonged for positive therapeutic moderately highly protein bound benefit. Drugs that are 30% to 60% bound to protein are Drug formulation and dose moderately protein- bound Route of Administration Drugs that are less than 30% bound to protein are low Size of the drug molecule protein-bound drugs Surface area of the absorptive site Digestive motility or blood flow Free drugs (drugs not bound to protein) Lipid solubility Are active and can cause a pharmacologic response Degree of ionization As the free drug in the circulation decreases, more Acidity or alkalinity (pH) bound drug is released from the protein to maintain the balance of free drug Interactions with food and other medications. Drugs bound to proteins cannot leave the systemic - acids are absorbed in acids, and bases are circulation to get to the site of action absorbed in bases - Dietary supplements may also affect absorption - The nurse should also check the patient's - High-fat meals can slow stomach motility plasma protein and albumin levels, because a significantly and delay the absorption of oral decrease in plasma protein (albumin) decreases medications taken with the meal. protein-binding sites, permitting more free drug in the circulation First-pass Effect Is the process in which the drug passes to the liver first Blood-Brain Barrier (BBB) or hepatic first pass. Is a semipermeable membrane in the central nervous In the liver, some drugs may be metabolized to an system (CNS) that protects the brain from foreign inactive form that may then be excreted, thus reducing substances the amount of active drug During pregnancy, Bioavailability Both lipid-soluble and lipid-insoluble drugs are able to Is a subcategory of absorption cross the placental barrier, which can affect the fetus It is the percentage of the administered drug dose that and the mother reaches the systemic circulation For the oral route of drug administration, bioavailability Distribution of Medications occurs after absorption and first-pass metabolism Amount of blood flow to body tissues Factors that alter bioavailability includes: heart, liver, kidneys, and brain 1. The drug form (e.g., tablet, capsule, Skin, bone, and adipose tissue sustained-release, liquid, transdermal patch, rectal suppository, inhalation) Lipid Solubility 2. Route of administration (e.g., oral, rectal, topical, - Some tissues have the ability to accumulate and parenteral) store drugs after absorption 3. Gl mucosa and motility The bone marrow, teeth, eyes, and adipose 4. Food and other drugs tissue have an especially high affinity, or 5. Changes in liver metabolism caused by liver attraction, for certain medications. dysfunction or inadequate hepatic blood flow. - With some oral drugs, rapid absorption Drug-protein complexes increases the bioavailability of the drug and can Drugs and other chemicals compete with one another cause an increase in drug concentration. Drug for plasma protein-binding sites, and some agents have toxicity may result. a greater affinity for these binding sites than other - Slow absorption can limit the bioavailability of agents. the drug, thus causing a decrease in drug serum Drug-drug and drug-food interactions may occur when concentration. one drug displaces another from plasma proteins. Drug to Drug Interactions A large percentage of drugs are lipid soluble; thus the liver metabolizes the lipid-soluble drug substance to a Addition - The action of drugs taken together as a total water-soluble substance for renal excretion Synergism - The action of drugs resulting in a potentiated (more than total) effect Half-life (t12) of a drug Antagonism - Drugs taken together with blocked or Is the time it takes for one half of the drug opposite effects. concentration to be eliminated Displacement - When drugs are taken together, one Metabolism and elimination affect the half-life of a drug. drug may shift another drug at a nonspecific For example, with liver or kidney dysfunction, the half-life protein-binding site (e.g., plasma albumin), thereby of the drug is prolonged and less drug is metabolized altering the desired effect and eliminated The brain and placenta possess special Example of Half-life anatomic barriers that prevent many chemicals If the patient takes 650 mg of aspirin and the half-life is and medications from entering 3 hours, it takes 3 hours for the first half-life to eliminate Substances such as alcohol, cocaine, caffeine, 325 mg, 6 hours for the second half-life to eliminate an and certain prescription medications easily cross additional 162 mg, and so on until the sixth half-life (or the placental barrier and can potentially harm 18 hours), when 10 mg of aspirin is left in the body the fetus Some medications such as sedatives, Excretion antianxiety agents, and anticonvulsants readily The main route of drug elimination is through the cross the blood- brain barrier to produce actions kidneys (urine). in the central nervous system Other routes includes: Bile, feces, lungs, saliva, sweat, and breast milk Metabolism Kidneys filter free unbound drugs, water-soluble drugs, Is the process by which the body inactivates or and drugs that are unchanged biotransforms drugs Drugs can be metabolized in Lungs eliminate volatile drug substances and products several organs. The liver is the primary site of metabolized to carbon dioxide (CO2) and water (H2O) metabolism Most drugs are inactivated by liver enzymes and are Excretion of Medications then converted or transformed by hepatic enzymes to Liver or kidney impairment inactive metabolites or water- soluble substances for Blood flow excretion Degree of ionization Lipid solubility Metabolism of Medications Drug-protein complexes - Metabolism, also called biotransformation, is Metabolic activity the process of chemically converting a drug to a Acidity or alkalinity (pH) form that is usually more easily removed from Respiratory, glandular or biliary activity (diffusion, gas the body. solubility, and pulmonary blood flow) Glandular activity is another elimination mechanism. First Pass Effect - During metabolism, the addition of Water-soluble drugs may be secreted into the saliva, side chains, known as conjugates, makes drugs more sweat, or breast milk water soluble and more easily excreted by the kidneys. Some drugs are secreted in the bile, a process known as biliary excretion - Most metabolism in the liver is accomplished by the hepatic microsomal enzyme system. This Drug Plasma Concentration and Therapeutic enzyme complex is sometimes called the P-450 Response system, named after cytochrome P-450 (CYP-450), which is a key component of the For each drug administered, the nurse's goal is to: system. - To keep its plasma concentration in the - Most metabolism in the liver is accomplished by therapeutic range the hepatic microsomal enzyme system. This - To keep the therapeutic range is quite wide of enzyme complex is sometimes called the P-450 some medications system, named after cytochrome P-450 - To take the difference between a minimum (CYP-450), which is a key component of the effective dose and a toxic dose may be system. dangerously narrow among other medications - First Pass Effect v.s. Prodrugs - Extreme of Ages Onset, Peak Levels, and Duration of Drug Action Alternative routes of delivery that bypass the Onset of drug action represents the amount of time it first-pass effect (e.g., sublingual, rectal, or takes to produce a therapeutic effect after drug parenteral routes) may need consideration administration. Peak plasma level occurs when the medication has Nursing interventions for controlled substances are reached its highest concentration in the bloodstream. as follows: Duration of drug action is the amount of time it takes Account for all controlled drugs for a drug to maintain its desired effect until termination Keep a special controlled-substance record for of action. required information - The most common description of a drug's Countersign all discarded or wasted medication; duration of action is its plasma half-life (t½), wastage must be witnessed defined as the length of time required for the Ensure that documentation and drugs on hand plasma concentration of a medication to match decrease by one-half after administration. Keep all controlled drugs in a locked storage area; keep narcotics under double lock Drug concentration (amount of drug given) Dosage (how often a drug is given or scheduled) WEEK 4-5: NURSING PROCESS IN Route of drug administration (oral, parenteral, or PHARMACOLOGY topical) Drug-food interactions THE NURSING PROCESS Drug-supplement interactions - Assessment Drug-herbal interactions - Nursing Diagnosis Drug-drug interactions - Planning - Implementation Factors influencing responses to drugs - Evaluation Disease Exercise ASSESSMENT Lactation & Pregnancy Collection of Data Fever & Infection Subjective Behavior Objective Age Accurate Renal function Immunologic function 1. Health history related to drugs Cardiovascular function Allergies Gastrointestinal function Nursing history; past and present medical history Dietary factor Pattern of health care Genetic Understanding of the disease Use of other drugs Drug-drug interaction 2. Physical Assessment Storage of drugs Age and weight Development of tolerance and resistance Measurement of vital signs Alcohol intake Social support Body size chronic conditions Drug Legislation controlled Substance 3. Diagnostic tests, Lab values, Diagnostic - Set of drug standards used in the United States procedures is the United States Pharmacopeia of 1820. - United States Pharmacopeia National Formulary 4. Medication History (USP-NF), the current three volume authoritative Prescriptions source for drug standards OTCs, medication profile - WHO Responses to medications (therapeutic and adverse - BFAD in the Philippines responses) - International Pharmacopoeia, first published in Medication profile 1951 by the World Health Organization (WHO) ✓ any and all drug use - Food and Drug Administration (FDA) ✓ use of home or folk remedies and herbal and/or homeopathic treatments The Controlled Substances Act (1970) ✓ plant or animal extracts ✓ dietary supplements Problem of drug abuse, included several provisions: ✓ intake of alcohol - promotion of drug education and research into ✓ Tobacco the prevention and treatment of drug ✓ Caffeine dependence ✓ Current or past history of illegal drug use - strengthening of enforcement authorities ✓ past and present health history and associated drug - establishment of treatment and rehabilitation regimen facilities - designation of schedules ✓ use of over-the-counter (OTC) medications (eg. - Critical thinking aspirin, acetaminophen, vitamins, laxatives, sinus - Creativity medications, antacids, antidiarrheals, minerals) - Accurate data collection ✓ use of hormonal drugs - It is a statement about the patient's status and ✓ Family history and racial, ethnic, and/or cultural will guide nursing interventions attributes with attention to specific or different responses to medications as well as any unusual individual PLANNING responses - Identification of goals (must be patient-centered) ✓ Growth and developmental stage - Outcome criteria ✓ Must be SMART Gather additional data about the patient and a given ✓ Have a time frame drug: - Prioritization - Patient's oral intake - Tolerance of fluids Planning phase of the nursing process are - Swallowing ability for pills, tablets, capsules, and behaviour based and may be categorized into: liquids - Physiologic - Results of laboratory - Psychological - diagnostic tests related to organ functioning and - Spiritual drug therapy - Sexual - renal function studies (e.g., blood urea nitrogen - Cognitive level, serum creatinine level) - Motor domains - patient's white blood cell and red blood cell counts PLANNING RELATED PHARMACOLOGY - Hemoglobin and hematocrit levels 1. Identification of possible interactions, knowledge of results of hepatic function tests the prescribed medication ✓ total protein level OTC drugs ✓ serum levels of bilirubin herbs ✓ alkaline phosphatase 2. Client and family education ✓ creatinine phosphokinase level of patient understanding of disease ✓ other liver enzymes level of education 3. Gather equipment, review procedures, safety Holistic nursing assessment: measures, timing and frequency of drugs, storage of physical/emotional realms religious preference drugs health beliefs sociocultural characteristics race ethnicity IMPLEMENTATION lifestyle stressors - Initiation and completion of the NCP as defined socioeconomic status educational level by the nursing diagnoses and outcome criteria motor skills cognitive ability - Refers to nursing interventions support systems use of any alternative and 1. Maximizing therapeutic effect complementary therapies 2. Minimizing the adverse effects 3. Rights of medication administration Assessment on specific drug : EVALUATION - prescribed - monitoring the patient's response to drug - OTC therapy - herbal/complementary/alternative therapeutic ✓ Expected outcome drug use ✓ Unexpected outcome - with attention to the drug's action - signs and symptoms of allergic reaction ELEMENTS OF MEDICATION ORDER - adverse effects 1. Name of the patient - dosages and routes of administration 2. Date order is written - contraindications; drug incompatibilities 3. Name of medication - drug-drug, drug-food, and drug- laboratory test 4. Dosage includes size, frequency and number of dose interactions 5. Route of delivery - toxicities and available antidotes 6. Signature of the prescriber NURSING DIAGNOSIS MEDICATION ORDERS - Decision about the needs or problems (Actual or risk 4 Categories for) 1. Standing order Three parts: - an ongoing order - Human response to illness - given for a specific numbers of doses/days - "related T" - Have special instructions - as evidenced by" - May include PRN orders 2. one-time Household - Given once, at a specific time, once a day 1 tsp= 5ml 3. PRN orders 1 tbsp= 3 tsp - given at client's request and nurse's judgment 1 ounce= 30 ml 4. Stat orders 2 pt = 1 quart (qt - given at once- immediately 4 qt = 1 gallon (gal) 60 drops (gtt) = 1 tsp RIGHTS OF DRUG ADMINISTRATION 32 tbsp = 1 pt 1. Right Drug 16 oz= 1pt= 2 cups (c) 2. Right Patient 16 ounces= 1 lb 3. Right Dose 4. Right Time Apothecary 5. Right Route grain (gr) 60 gr = 1 dram (dr) 1 gr = 60 mg 6. Right Documentation gr ii is 2 grains gr xv is 15 grains 13 Rights of Medication Administration Gr xv = 1 gm 7. Right Assessment 8 dr = 1 ounce (oz) 8. Right of the patient to refuse 60 min = 1 fluidram (fl dr) 9. Right Medication 8 fl dr = 1 fluid ounce (fl oz) 10. Right Reason 11. Right Effort Examples: 12. Right of Expiry date 2 tsp= 10 ml (2 tsp x 5 ml= 10 ml) 13. Right of Education 8 oz 240 ml 100kg = 220 lb Others right gr 3/4= 45mg ✓ Patient safety, ensured by use of the correct procedures, equipment, and techniques of medication Three ways: administration and documentation Ratio and Proportion (solving for X) ✓ Individualized, holistic, accurate, and complete patient Dimensional Analysis (Preferred Method) education Formula ✓ Double-checking and constant analysis of the system (process of drug administration and patient's education) ✓ Proper drug storage ✓ Accurate calculation and preparation of the dose of medication and proper use of all types of medication delivery systems ✓ Careful checking of the transcription of medication orders ✓ Accurate use of the various routes of administration and awareness of the specific implications of their use ✓ Close consideration of special situations (patient difficulty in swallowing, use of a nasogastric tube, Dimensional Analysis unconsciousness of the patient and others) - Set up units of measurement so that they cancel ✓ Implementation of all appropriate measures to out, until you arrive at your correct measurement prevent and report medication errors - Always start with the dose ordered DRUG COMPUTATIONS 10mg x 1 Tab = 10 Tab 1 5mg 5 MEASURING SYSTEMS = 2 Tablets Metric System Apothecary System Household System Metric System gram (g) 1 milligram (mg) = 0.001 g 1 g = 1000mg 1 microgram (mcg) = 0.000001 g 1 kilogram (kg) = 1,000 g 1 liter = 1000ml 1 ml = 1 cc  Nursing Interventions Related to Pharmacology Nursing Intervention - Is an implementation which is guided by the preceding phases of the nursing process (i.e., assessment, nursing diagnoses, and planning) - It requires constant communication and collaboration with the patient and with members of the healthcare team Identify the process of nursing intervention for patients related to pharmacology Develop a nursing care plan that is based on the nursing process as it relates to medication administration. Discuss the process of formulating nursing diagnoses for patients receiving medications Components of Nursing Intervention - Independent - Collaborative - Dependent Statements of interventions include: - Frequency - Specific instructions - Any other pertinent information Implementation - Initiation and completion of the nursing care plan as defined by the nursing diagnoses and outcome criteria Nursing Intervention in Medication administration - Maximizing therapeutic effect - Minimizing adverse effects Provide comfort measures and help patient cope with the therapeutic or adverse effects of a drug Observe the rights in giving medications Monitor the patient's response to drug therapy Patient should receive the drug that was prescribed Medication should be written in the chart and prescription pad Check that the medication order is complete and legible Know the reason why the drug is being administered to client Medication chart/Kardex should include the date the medication was ordered and any last date The first dose, one time and "as needed" medication orders should be checked against original orders Be aware of certain drugs that sound alike an spelled similarly Calculate dose correctly. When in doubt, it should be calculated and checked by another nurse Check references or drug package for recommended range of specific drug dose Check the expiration date Use aseptic technique when preparing and administering the medication  Administer the appropriate site Before giving the medications, verify the name of the patient If necessary to combine medication with another substance, explain it to the patient Advise patients not to eat high-fat foods before ingesting an enteric-coated tablet; high-fat foods decrease the drug absorption rate. Notify the health care provider of drugs ordered that have antagonistic or opposite effects, such as beta stimulants and beta blockers Other nursing intervention that needs documentation includes the following: 1. If a drug is not administered with the reason why and any actions taken 2. Refusal of a medication with information about the reason for refusal, if possible; if a medication is refused, respect the patient's right 3. Actual time of drug administration 4. Data regarding clinical observations and treatment of the patient if a medication error has occurred Medication error - As any preventable event that may cause or lead to inappropriate medication use or patient harm while the medication is in the control of the health care professional, patient, or costumer Evaluation - Is the part of the nursing process that includes monitoring whether patient goals and outcome criteria related to the nursing diagnoses are met.