Pharmacology Notes NSG 3301
Popular in Pharmacology
verified elite notetaker
verified elite notetaker
verified elite notetaker
PSYCH-UA 10 - 001
verified elite notetaker
verified elite notetaker
verified elite notetaker
Popular in Nursing and Health Sciences
This 148 page Bundle was uploaded by Kate on Tuesday May 10, 2016. The Bundle belongs to NSG 3301 at Troy University taught by in Spring 2016. Since its upload, it has received 17 views. For similar materials see Pharmacology in Nursing and Health Sciences at Troy University.
Reviews for Pharmacology Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 05/10/16
Pharmacology Chapters 1 & 2 Exam 1 Chapter 1: Nursing Management of Drug Therapy Core Drug Knowledge Pharmacotherapeutics—the desired, therapeutic effect of the drug (what it’s prescribed for) Pharmacokinetics—the changes that occur to the drug while it is inside the body Pharmacodynamics—the effects of the drug on the body Contraindications and precautions—the conditions under which the drug should not be used or must be used carefully with monitoring Adverse effects—the unintended and usually undesired effects that may occur with the use of the drug Drug interactions—the effects that may occur when the drug is given along with another drug, food, or substance Core Patient Variables—assessment of pt centered variables Health status—overall health of the patient, presence of disease, illness, and allergy; chronic conditions causing systems or organ dysfunction; diminished memory or mental capacity Life span and gender—age, physiologic development, reproductive stage, ability to read and write, and gender Lifestyle, diet, and habits—occupation, finances, substance use, exercise Environment—where will the drug be administered Culture and inherited traits—cultural beliefs; may affect the pt’s receptiveness to drug therapies o Genetic traits can affect a drug’s pharmacokinetic and pharmacodynamics properties Nursing Management of Drug Therapy—plan and implement action steps Maximize the therapeutic effects of a drug Minimize the adverse effects of a drug Provide patient and family education Evaluates effectiveness of both drug therapy and nursing interventions Health Care Settings Hospitals Longterm care facilities Outpatient centers and clinics Health care providers’ offices Patients’ homes Drug Usage in the U.S Approximately 45% of US population takes at least one medication in a month Prescription drug use increases with each age group Approximately 85% of adults aged 65 and older are receiving one prescription per month Almost 50% of adults aged 65 and older are receiving three or more prescriptions a month Nursing Management of a Drug—process of planning and implementing actions that will maximize therapeutic effects and minimize the adverse effects of a drug. Assessment: o Current medications a patient is taking o Interaction between medications o Use of resources to identify drugs that are unfamiliar o Use of prototype drugs to increase understanding of different medications Prototype drug—typical of a medication within a drug class Typically the first drug of a class 1 Pharmacology Chapters 1 & 2 Exam 1 Drug has similar characteristics to all drugs in a class of drugs Provides a systematic way to increase knowledge of medications Sources of Assessment Data Patient Interview and History o Health Status—assess functioning of body systems and organs Presence of acute or chronic disease Drug history (see chart below) Sensory deficits Ability to understand spoken instruction Cognitive or memory deficits Components of a Complete Drug History Currently prescribed medications Prescribed dosages/routes When each was taken last Description why medication Other prescribed medications Reason medications stopped prescribed taken in past Known drug allergies When allergic effect occurred Description of specific allergic effect Known food or environmental OTC medications used Frequency of OTC drug use allergies Last time OTC drugs were used o Lifespan and Gender—needed to plan pt education on drug therapy Age and developmental level Ability to read and write Female pts—reproductive status o Lifestyle, Diet, and Habits—can cause potential effect on drug therapy Occupation Insurance and other economic resources to pay for drug therapy Activity and exercise patterns; sleep and rest patterns Dietary patterns—frequency of meals/snacks, foods usually eaten, foods avoided Dietary supplements Complementary medicine Street illegal drugs used Alcohol used—amount, last time Cigarettes or other nicotinecontaining products Caffeine o Environment—pt’s adherence to drug regimen—Will they take it? Do they have support? Potential risks from the therapy where the drug will be administered Description of home setting/living accommodations Location of home o Culture and Inherited Traits—affect the pt’s acceptance of prescribed drug therapy Physical Exam o Focus on health status, life span, and gender o Comprehensive—physicals assessment of each body system o VS, ht, wt (helps with dosage) Medical Record: o Provides info about pt’s health status, lifestyle, diet, habits, and environment 2 Pharmacology Chapters 1 & 2 Exam 1 o Lab test and diagnostic test results o Drug history Objective Data—measurable data that the nurse collects Subjective Data—what the patient tells the nurse Purpose of Data Collection Interpretation of data based on their relevance to drug therapy Nurse uses the drug knowledge and patient variables to determine any significant drug interactions Nursing Diagnosis NANDA Reflect a current, actual problem or the risk for developing a problem related to drug therapy Diagnoses may reflect effects of drugs Nursing diagnoses are highly individualized Selected Nursing Diagnoses Pertaining to Drug Effects Constipation Diarrhea Acute Pain Chronic Pain Fatigue Risk for Infection Risk for Injury Disturbed Sensory Perception Ineffective Sexuality Patterns Disturbed Sleep Pattern Disturbed Thought Processes Interrupted Breast Feeding Acute Confusion Deficient Fluid Volume Excess Fluid Volume Imbalanced Nutrition Impaired Urinary Elimination Urinary Retention Nursing Outcomes Determine desired results Based on data collected Specific to the patient’s drug regimen Maximizing Therapeutic Effects Administer the drug in a manner that will promote its absorption Administer the drug at the appropriate time—appropriate dosage and time intervals Monitor lab values Minimizing Adverse Effects Verify pt allergies*—determine if true allergy or side effect of med (pruritis) Assess for contraindication for the drug therapy Administer the drug in a manner consistent with standard safely protocols Monitor the patient and relevant lab findings Discontinue or withhold a drug based on assessment or lab findings Report evidence of adverse effects to prescriber o Can report new/unreported AE of drugs to MedWatch Modify administration techniques, when appropriate Implement appropriate assessment for certain drugs to detect the onset of adverse effects Core Drug Knowledge Understand the drug’s response Basics of teaching pt. and family about drug therapy o Name of drug—generic and trade o Reason drug was prescribed (pharmacotherapeutics) o Intended effect of drug (pharmacodynamics) o Important adverse effects that may occur—anticipated and AE 3 Pharmacology Chapters 1 & 2 Exam 1 Never tell a pt that something isn’t an adverse effect—all drugs have AEs Core Patient Variables Health status—activities that must be performed while the pt. receives the drug o Lab tests, bleeding time, periodic examination/assessment Life span and gender—adverse effects on a developing fetus; used for pt education Lifestyle, diet, and habits—changes the pt may need to make during therapy Environment—to promote effective selfmanaged drug therapy Culture and inherited traits—consider cultural issues and modify content or presentation accordingly Evaluation Measures the pts. progress Consider whether the drug achieved the desired effect Outcomes that are not achieved o Reassess to identify barriers to success Must identify the reason behind any treatment failure Chapter 2: Pharmaceuticals: Development, Safeguards, and Delivery Sources of Drugs: Plants—morphineopium poppy, digitalis, vincristine Animals—insulinpig Synthetic chemicals Genetically engineered chemicals Plants Date to primitive times Classified according to their physical and chemical properties o Alkaloids—react with body acids to form a salt, which is readily soluble in body fluids o Glycosides—contain carbohydrate or sugar molecules o Gums—mucilaginous secretions with ability to attract and hold water o Oils—insoluble in water and are classified as volatile (strictly plants and evaporate when exposed to air) or fixed (fatty oils derived from animals and plants with a varying consistency with temperature) o Resins—solid or semisolid, water insoluble, organic substances of vegetable origin that are commonly used as laxative/causative agents **Genetically engineered drugs have less drug reactions than those made from animals** Animals Traditionally, drugs from animal sources include agents such as insulin, pituitary hormones, vitamins, antibiotics, vaccines, and immune serums **Today, genetically engineered hormones are rapidly replacing animalbased drugs Advantage: purity Synthetic Chemicals Most drugs used today are either partially or wholly synthetic chemical compounds. A partially synthetic agent contains a derivative of a natural substance combined with a pure chemical. 4 Pharmacology Chapters 1 & 2 Exam 1 An advantage of synthetic drugs is that they are pure chemicals. Genetically Engineered Chemicals Genetically engineered drugs are drugs developed using DNA technologies. *Genomics—the study and identification of genes and gene function This new knowledge has enabled researchers to manipulate the chemical formulas of drugs to produce more specifically targeted drugs with fewer adverse effects. Proteomics—the study of protein structure and function. Proteomic technology—is essential in biomarker discovery o Biomarker—substance that is introduced to an organism as a means to examine organ function Transcriptomics—the study of the transcriptome (complete set of RNA transcripts produced by the genome at any one time) o Aids in understanding the development and differentiation of a cell Metabonomics—the study of metabolic responses to drugs, environmental changes, and diseases. In pharmacotherapy, metabonomics can possibly predict an individual patient’s response to drug treatment. Pharmacogenomics—application of omics technology for the prediction of the sensitivity or resistance of pt’s disease to specific drug or group of drugs Pharmacogeneics—study of how genetic variables affect pharmacodynamics Drug Nomenclature Chemical name: precisely describes the drug’s atomic and molecular structure o Rarely used Generic name: nonproprietary name—identifies the drug’s active ingredient o Lowercase Trade name: brand or proprietary name o Capitalized Example: Chemical name—pisobutylhydratropic acid Generic name—Ibuprofen Trade name—Tylenol, Motril, Midol IB Implications for Nursing Drug should be ordered by generic name Many trade names sound alike Nurse should check the drug name at least 3 times Pharmacy bar code system For furosemide (Lasix), furosemide is the generic name Drug classifications Drugs that have similar characteristics are classified as a pharmacologic group or family Allows for increased understanding of meds Can be classified by: o Chemical classification—morphine sulfate chemical base of opium o Physiologic classification—describes its effect on body systems, such as CNS depressant for morphine o Therapeutic classification—describes drug by its use in therapy, such as morphine as an opioid narcotic analgesic Sources of Drug Information 5 Pharmacology Chapters 1 & 2 Exam 1 New drugs continually being developed Nurses need reliable and uptodate drug references: o Drug publications o Pharmacists o Internetbased drug guides When unfamiliar with a drug you should always look it up before administering Standards for Drug Purity and Content United States Pharmacopeia (USP) is source for standards of strength, quality, purity, and preparation of medical compounds Legislation for Drug Safety and Efficacy: protects public from drugs that are impure, toxic, ineffective, or not tested before marketing to ensure safety Pure Food and Drug Acts—protected the public from adulterated mislabeled drugs and empowered the federal government to enforce these standards o Became law mostly because of revelations of unsanitary and unethical practices in the meatpacking industry and because of the many potent and dangerous drugs on the market Federal Food, Drug, and Cosmetics Act of 1938—in response to a considerable number of deaths caused by marketing of elixr sulfanilamide o Established the FDA to monitor and control drug manufacturing and marketing o Drug labels must contain the following: No false/misleading statements Suggested dose and frequency use Name and business address of manufacturer/packer Amount of all dependency producing drugs in a product with warning Kind, quality, and percentage of certain ingredients Complete, understandable directions KefauverHarris Amendment— as a result of the thalidomide tragedy in Europe o Tightened control on drug safety, especially experimental drugs, stating that adverse reactions and contraindications must be cited and included in literature o Ordered evaluation of the testing methods used by manufacturers o United States Adopted Names Council Procedure for Drug Development and Approval First step is in the discovery of a potential new drug molecule Preclinical trials—designed to provide basic safely, bioavailability, pharmacokinetic, and initial efficacy data about the drug o Last up to 3½ years and only 1 of every 1000 compounds make it out) Clinical trials—performed on humans in several phases lasting between 59 years Only about 10% of drugs that begin clinical trials are approved—avg. of 12 years & $350 million Phase III of drug trials is where the majority of risks are associated with the drug. PHASE I Introduces drug into humans Goal is to determine metabolic and pharmacologic actions of the drug in humans, adverse effects with increasing doses, and to gain early evidence of effectiveness PHASE II Wellcontrolled, closely monitored, and conducted on several hundred people Goal: obtain preliminary data on effectiveness of drug for indications in patients with certain disease or condition Results from long term animal studies and human results compared especially concerning effects on fertility and reproduction 6 Pharmacology Chapters 1 & 2 Exam 1 PHASE Controlled and uncontrolled trials to uncover infrequent or rare adverse effects III Several hundred to thousand patients unrolled in a double blind study and crossover Nurses most involved in this phase: addressing patients feeling towards study (placebo response occurring relatively consistently in 2040% of patients in all studies) Now application for new drug (NDA) PHASE NDA approves and drug is now on the market IV FDA conducts postmarketing surveillance to monitor drug for safety/new developments Effects on children and elderly are studied Programs to ensure postmarketing surveillance include: MedWatch and Practitioners’ Reporting Network Legislation to Promote Truth in Advertising In 1912, Congress passed the Sherley Amendment o Prohibited drug manufacturers from making fraudulent therapeutic claims about their products The FFDCA of 1938 provided labeling requirements for the first time Today the Federal Trade Commission regulates the advertisement of meds aimed at the general public Controlled Substance Legislation Harrison Narcotic Law of 1914—provided regulation regarding the manufacture and distribution of certain drugs The 1970 Comprehensive Drug Abuse Prevention and Control Act—established the Drug enforcement act (DEA): regulatory body responsible for the safe distribution and control of potentially addictive drugs o Five categories, known as schedules, were established CATEGO ABUSE DEPENDA EXAMPLES RULES GOVERNING RY POTENT NCE PRESCRIPTION IAL LIABILITY C-I High Severe Heroin, hashish, LSD, GHB No accepted medical use the US There is a lack of accepted safety for use of the drug or other substance under medical supervision C-II High Severe Amphetamines, some opoid Requires tamper proof narcotics (morphine/meperidine), prescription dronabinol, short acting Telephone orders not bartbituates accepted (phenobartbitol/secobarbital) Refills not allowed Additional medication requires new prescription C-III Moderate Moderate Some opioid narcotics (codeine, A written or telephone order hydrocodone), some CNS is acceptable stimulants, anabolic steroids May be refilled 5 times within 6 months from the date of issue Prescription must be 7 Pharmacology Chapters 1 & 2 Exam 1 rewritten after 6 months and 5 refills C-IV Low Limited Benzodiazepine anxiolytics, Same as C-III drugs anticonvulsants, muscle relaxants, and sedatives; nonbenzodiapine hypnotics and intermediate acting barbiturates; opioid narcotics such as propoxyphene or pentazoine C-V Limited Lowest Antidiarrheal preparations with Many of these drugs may be diphenoxylate and loperamide; obtained without a small amounts of narcotics such prescription as codeine used as antitussives Nursing Management of Controlled Substances Prescribing, dispensing, and storing is subject to government control Procedures are defined by law for every step from administering to wasting Automated systems are used in many hospitals to track the use of stock drugs Use of narcotic log sheet includes: date/time of administration, drug name and dose, pt name, prescriber’s name, and administering nurse’s name Drug Distribution DurhamHumphrey Amendments (1952)—separated drugs into two classes: o Nonprescription drugs (over the counter) o Legend (prescription) drugs Labeled properly: must be identified by legend (inscription) on container Caution federal law prohibits dispensing without prescription Controlled substances must also display a warning label Procedures for distribution of legend drugs Online Pharmacies Increased usage Not all online pharmacies are regulated Ryan Haight Internet Pharmacy Consumer Protection Act of 2005—sale of controlled substances through internet o Restrict delivery, distribution, or dispensing of controlled substances by means of the internet without valid prescription obtained through a provider in a onetoone inperson medical evaluation Nongovernmental Institutional Controls Institution can implement additional regulations Accrediting bodies play an additional role in institutional controls Effect Of Legal And Intuitional Controls on Nursing Management of Drug Therapy Drug laws and nurse practice acts vary state to state Nurse must be familiar with current state and institutional regulations Nurse must obey drug control laws and protocols Nurse cannot provide drug therapy without proper authorization Nurse is responsible for drug security and safe administration Pt. Education Key safeguard in drug therapy* 8 Pharmacology Chapters 1 & 2 Exam 1 Patient learning needs o Learning needs vary among each patient from nursepatient relationship, scope/complexity of drug therapy, or core patient variables Teaching focus and content o Individualize and communicate information so that the pt or caregiver can understand it and act on it appropriately Evaluation and documenting educational outcomes o Timing of teaching, content of teaching, pt’s response to the teaching session, evaluations of grasp of subject matter, and assessment of unmet or future learning needs Consumer drug information on the internet o Consumers may have trouble discerning difference between accurate drug information and personal web pages that have biased medical opinions Importance of Nursing Management of Drug Therapy Nurses are legally responsible for the drugs they administer Nurse needs to have thorough understand of therapeutic drug actions and adverse drug reactions In some settings, nurses can modify drug regimens Application of the nursing process to pharmacologic aspects of pt care is especially important because longterm use of drug therapy is frequently necessary to control chronic disease processes 9 Ch. 13: Drugs Affecting Adrenergic Function Pharm Exam 3 Chapter 13: Drugs Affecting Adrenergic Function Summary: p. 163 Adrenergic agonists: mimic the action of the SNS The nervous system is divided into two main branches, the central nervous system (CNS) and the peripheral nervous system (PNS). PNS: divided into Afferent & Efferent divisions o The efferent division has neurons that carry signals away from the brain and spinal cord to the periphery. Divided into somatic and autonomic The autonomic nervous system (ANS) is in turn subdivided into the sympathetic nervous system (SNS) and the parasympathetic nervous system (PSNS) Parasympathetic Nervous System: cholinergic; acetylcholine o Rest and digest Sympathetic Nervous System: adrenergic; epinephrine o Figh or flight Find picture/list of Parasympathetic and Sympathetic NS functions o **Myosis=constriction. Mydriasis=dilation o The afferent division contains neurons that carry impulses from the periphery to the CNS. Alpha1: vessels in periphery, control BP; respond to all 3 NTs Alpha2: in CNS; decreases sympathetic outflow; respond to epi & NE Beta1: heart; respond to all 3 NTs Beta2: lungs; respond only to EPI Function of the ANS: The ANS has been identified as an involuntary system responsible for the control of smooth muscle. The actual connection between neurons and effector organs or tissues relies on neurotransmitters and synaptic transmission. The NTs in the ANS include acetylcholine (ACh; primarily in cholinergic), norepinephrine (NE), and epinephrine (Epi). Synaptic transmission initially involves the synthesis of neurotransmitters in the nerve terminal. In the SNS, preganglionic transmission is mediated by ACh, whereas postganglionic transmission is mediated by NE. SNS: mydriasis (pupil dilation), ↑ HR, diaphoresis, etc. Adrenergic Receptors The ANS has been identified as an involuntary system responsible for the control of smooth muscle. The actual connection between neurons and effector organs or tissues relies on neurotransmitters and synaptic transmission. The neurotransmitters in the ANS include acetylcholine (ACh), norepinephrine (NE), and epinephrine (Epi). Synaptic transmission initially involves the synthesis of neurotransmitters in the nerve terminal. In the SNS, preganglionic transmission is mediated by ACh, whereas postganglionic transmission is mediated by NE. Pathophysiology The therapeutic uses of sympathetic drugs are related to providing extraadrenergic stimulation or blockade of normal ANS functioning. 1 Ch. 13: Drugs Affecting Adrenergic Function Pharm Exam 3 One of the most frequent indications for adrenergic agonist drugs is shock. Shock is the result of inadequate tissue perfusion, leaving the cells without the oxygen and nutrients they need to function normally and survive. ADRENERGIC AGONISTS Adrenergic agonists are drugs that mimic the action of the SNS. They exert their effects by direct or indirect stimulation of adrenergic receptors. These drugs are generally divided into two groups— catecholamines and noncatecholamines. Adrenergic agonists are also classified according to their selectivity. Nonselective adrenergic agonists stimulate both alpha and beta receptors. o Prototype drug nonselective adrenergic agonist—epinephrine. Alpha Adrenergic Agonsits o Prototype Alpha1 Adrenergic Agonist: phenylephrine o Prototype Alpha2 Adrenergic Agonist: clonidine BetaAdrenergic Agonists o Mimic the action of the SNS o Labeled according to selectivity o Prototype: dopamine Dopaminergic Receptor Agnoists o 5 types of dopamine receptors Only dopamine1 and dopamine2 receptors mediate responses in the adrenergic NS Stimulation of DA1 and DA2 results in peripheral vasodilation (↓ BP) Stimulating both receptors may have either complementary or opposing effects o Prototype DA1 Receptor Agonist: fenoldopam (Corlopam) o epinephrine (adrenaline) – Nonselective Adrenergic Agonists (stimulate alpha1 & 2 and beta1 & 2; will increase HR and BP) Wide variety of indications: asthma, anaphylactic shock, hypersensitivity reaction, cardiopulm. Resuscitation, Vfib Admin: parenterally (IV or IM), topically, inhalation. Metabolized: liver. Absorbed into tissues. Excreted: kidneys. Duration: 14 hours. Stimulates all adrenergic receptors and causes adverse effects in the CV system and CNS. CI/Prec: hypersensitivity, sulfite sensitivity, closedangle glaucoma, use during labor. o Severe organic cardiac disease, cerebrovascular disease, hypertension Adverse Effects: hypertensive crisis, angina, cerebral hemorrhage, cardiac arrhythmias (related to stimulation of alpha and beta receptors) o Tremor, weakness, dizziness, pallor, palpitations, apprehensiveness, sweating, N/V Drug Interactions: TCAs, oxytocics, halogenated anesthetics, beta blockers o May interfere with blood glucose determinations. Document preadmin vital signs, pt’s occupation and daily activities, & review pt’s health hx IV admin only by trained personnel Requires close monitoring VS (BP, HR, ECG) and careful monitoring for AE 2 Ch. 13: Drugs Affecting Adrenergic Function Pharm Exam 3 Teach pt to take as prescribed and how to admin properly Teaching with acute illness: should be brief, simple, and supportive Advise pts to avoid OTC drugs containing sympathomimetic ingredients. If pt experiences angina, tachycardia, or cardiac arrhythmias, admin a betablocker. If pt experiences hypertension, admin an alphaadrenergic blocking agent. Assess pt for resolution of the presenting problem. Important to remember that epi is a nonselective adrenergic agonist Drugs Closely Related: o Norepinephrine (Levophed)doesn’t stimulate beta2 receptors. Drugs Significantly Different: o Ephedrine (not a catecholamine) used to treat hypotension o Vasopressin (ADH) phenylephrine (Allerest) – Alpha1 Adrenergic Agonists (directly stimulate alpha1 receptor) Pharmacotherapeutics: o Parenterally for vascular failure in shock o Topically for relief of nasal muscosal congestion (causes nasal vessel constriction) [and mydriasis] Admin: parenterally, topically. Metabolism: liver. Excreted: urine. Onset: 1520 min. Duration: 12 hours. T½: 23 hours Structurally similar to epi and is a powerful alpha1 adrenergic agonist. o Predominant actions in the vascular system (acts as vasopressocauses vasoconstrictionrenal perfusion & CO decrease; BP is increased. CI/Prec: Hypersensitivity, sulfite sensitivity, severe HTN, ventricular tachycardia, closedangle glaucoma. o Precaution during hyperthyroid states, DM, asthma. Adverse Effects: HA, restlessness, excitability, reflex bradycardia, rebound nasal congestion Drug Interactions: MAOIs, TCAs, ocytocics Assess medical hx (DM, hyperthyroidism, asthma) & obtain baselines Document the pt’s occupation and ADLs Used in pregnancy only if absolutely necessary Closely monitor during admin in acute care setting Correct any blood loss prior to admin For mydriasis, instill into conjunctival sac IV admin is through a large vein Avoid driving at night b/c blurred vision can be hazardous o Advise pt to use caution when driving at night or under bright light o Stress hazards associated with driving and operating heavy machinery Time doses to prevent disrupting sleep Prolonged use for nasal congestion more than 35 days can cause rebound congestion Closely related: o Methoxamine (Vasoxyl) 3 Ch. 13: Drugs Affecting Adrenergic Function Pharm Exam 3 clonidine (Catapres) – Alpha2 Adrenergic Agonist Stimulation of A2 receptors in the CNS decreases sympathetic outflow by inhibiting the release of NE Its stimulation results in decreased BP, decreased vasoconstriction, and decreased renal vascular resistance Admin oral, transdermal, parenteral o Transdermal constant rate for 7 days Adverse effects: dry mouth, drowsiness, dizziness, sedation, constipation Can be used to prevent the symptoms of narcotic withdrawal dopamine (Intropin) – Alpha1 and Beta1 Adrenergic Agonist Used to correct hemodynamic imbalances present in shock o Affects contractility of the heart o For tx to be most effective, pt should not be experiencing severe disruptions in urine production, myocardial function, and BP. Admin: IV only in critical care environment. Distribution: throughout the tissues. Metabolism: kidneys, liver & plasma. Excreted: kidneys. Onset: 5 min (fast). Duration: 10 minutes Stimulates alpha1 & beta1 receptorsincreases CO (increases contractility) o Systolic blood pressure increases CI/Prec: pheochromocytoma (adrenal tumor), uncorrected tachyarrhythmia, Vfib o Correct acidosis before starting therapy Adverse Effects: ectopic beats, N/V, tachycardia, angina, palpitation, dyspnea, HA, hypotension, vasoconstriction Drug Interactions: phenytoin, oxytocic drugs, TCAs, methyldopa Assess medical history for chronic illness and allergies Admin only in acute care settings Admin IV dopamine using infusion pump to regulate flow o Titrate dose to desire effect Follow manufacturer’s instructions for dilution Monitor IV site; if extravasation occurs, inject the area with phentolamine Assess for disproportionate rise in diastolic BP If administered during a crisis, limited teaching occurs at that time Reassure pt and pt’s family that pt will be monitored closely during admin of the drug Tx is effective if BP stabilizes, urine output returns to normal, and CO returns to normal o Monitor BP, urinary flow, CO Drugs Closely Related: o Dobutamine, Isoproterenol, Mephentermine, Metaraminol Drugs Different: o Midodrine, Beta2 Agonists fenoldopam (Corlopam) – DA1 Receptor Agonist 4 Ch. 13: Drugs Affecting Adrenergic Function Pharm Exam 3 Used for the shortterm management of severe HTN Admin: parenterally. Metabolism: conjugation in the liver. Excreted: urine & feces. Steady State: 20 min. Binds to DA1 receptors (does NOT bind with DA2, alpha, or beta receptors). Provides rapid vasodilation to the coronary, renal, mesenteric, and peripheral arteries. CI/Prec: hypersensitivity to sulfites o Monitor pts with a hx of glaucoma or intraocular pressure during infusion Adverse Effects: symptomatic hypotension, tachycardia, abdominal or back pain, GI effects, sweating, CNS effects (insomnia, dizziness, nervousness, anxiety), cardiac arrhythmias, angina, heart failure Drug Interactions: beta blockers, diuretics Admin only in the acute care hospital setting Maximizing Therapeutic Effects: o Dilute with 0.9% NaCl or 5% dextrose o Admin using infusion pump Never admin as IV push o Titrate dose to effect Minimizing Therapeutic Effects: o Visually inspect the drug ampule o Start at low doses and titrate up to avoid reflex tachycardia o Monitor HR & BP continuously (especially during administration) o Discard diluted solution that is not used within 24 hrs of prep Drugs Significantly Different: o Carbidopalavodopa ADRENERGIC ANTAGONISTS AlphaAdrenergic Antagonists Block the stimulation of alpha receptors Alpha1a receptors mediate human prostatic smooth muscle contraction Alpha1b and alpha1d receptors are involved in vascular smooth muscle contraction prazosin (Minipress) – Alpha1Adrenergic Antagonist Tx CHF, Raynaud vasospasm, prostatic outflow obstruction (like BPH) Admin: oral Metabolism: liver w/o involvement of p450 enzymes. Excreted: bile, feces, urine. Onset: 1 hour. Duration: 10 hours. T1/2: 24 hours Blocks postsynaptic alpha1 adrenergic receptors: lowers supine and standing blood pressure from dilated arterioles and veins CI/Prec: hypersensitivity; use caution with angina b/c hypotension may worsen the condition; use caution in pt with CHF or renal failure Adverse Effects: lightheadedness, dizziness, headache, drowsiness, weakness, lethargy, nausea, palpitations, reflex tachycardia, orthostatic hypotension, nasal congestion, inhibition of ejaculation, “first dose syncope” 5 Ch. 13: Drugs Affecting Adrenergic Function Pharm Exam 3 Drug Interactions: other antihypertensive meds, especially alpha or betablocking agents; drugs used for erectile function; alcohol Use caution sten operating machinery, exercising, driving, changing positions, climbing stairs (until 4 hours after 1 dose) Refrain from using OTC drugs Take the first dose before bedtime Monitor weight and check for edema Monitor BP, heart & lung sounds, & edema Drugs Closely Related: o Alfuzosin (Uroxatral), doxazosin ( Cardura), tamsulosin (Flomax), terazosin (Hytrin) Drugs Different: o Phentolamine (Regitine, Oraverse) o Phenoxybenzamine (Dibenzyline) BetaAdrenergic Antagonists Stimulation of beta1 only (tachycardia, increased lipolysis, inotropy) Stimulation of both beta1 and beta2 receptors (vasodilation, decreased peripheral resistance, bronchodilation) metoprolol (Lopressor, Toprol XL) Tx of hypertension, angina, controlled CHF, irreg cardiac rhythms, after MI Admin: parenterally & orally Metabolism: liver Excreted: urine & breast milk After oral adminpeak occurs within 1.54 hours; hypotensive stability may not occur for 23 weeks T½: 38 hours ↓ CO & BP; slowing of AV conduction and suppression of automaticity ↓ O2 demand CI/Prec: severe bradycardia, cardiogenic shock, airway diseases, Raynaud Syndrome, use of antidepressant drugs, complete heart block, uncompensated cardiac failure, sick sinus syndrome, pheocytochroma Adverse Effects: cognitive dysfunction, hypoglycemia, diarrhea, severe HTN, angina, myocardial ischemia, ventricular arrhythmias, pruritis, rash, diarrhea, dizziness, fatigue, HA, depression, dyspnea Drug Interactions: several Assess BP, CV status, GU function, mental & neuro status; heart and lung sounds Exercise caution when driving or operating machinery Do not abruptly stop medication Prior to dose, check apical and peripheral pulses (withhold if too low) Monitor CV status: BP, HR, edema Drugs Closely Related: o acebutolol (Sectral), atenolol (Tenormin), betaxolol (Betoptic), bisoprolol (Zebeta), esmolol (Brevibloc) Drugs Different: o Carvedilol, Labetalol, Sotalol (Betapace) 6 Ch. 13: Drugs Affecting Adrenergic Function Pharm Exam 3 7 Pharmacology Chapters 4 & 5 Exam 1 Chapter 4: Pharmacotherapeutics, Pharmacokinetics, & Pharmacodynamics Pharmacotherapeutics is the achievement of the desired therapeutic goal form drug therapy Study of the clinical purpose (the indication) for giving a drug Desired pharmacotherapeutics can be to induce a cure or prevent a problem Nurse needs to question the order if the intended effect does not correlate with the pts. reason for receiving drug therapy Pharmacokinetics—movement of the drug particles inside the body Absorption—movement of the drug form the site of administration into the bloodstream Distribution—movement of the drug into the cells Metabolism—conversion of the drug into another substance or substances Excretion—removal of the drug Drugs Moving Through the Body Drug molecules move during all phases of pharmacokinetics Drugs cross cell membranes in one of three ways: o First, they can pass between spaces or channels between the molecules in the membrane o Second, drugs can pass through the membrane with the help of a transport system o Third, drugs can penetrate the membrane directly The chemistry of drug particles also affect the movement of the drug throughout the body Absorption Several variables affect the rate of drug absorption o Depends on the route of administration o Affected by the speed at which the drug dissolves Drugs that are administered orally generally take the longest to be absorbed o Food or other drugs can interfere with absorption Drugs given parenterally are absorbed more rapidly than oral administration o IM is more rapid than SubQ o Drugs administered IV are placed directly in the bloodstream Large surface areas increase the rate of absorption Blood flow affects the rate—greater the volume of blood flow, the faster the rate of absorption Lipid solubility alters absorption pH effects rate also Core Patient Variables and Drug Absorption: Health Status: o Any change related to circulation, condition of GI tract, pH of body fluids can reduce o Contact time, surface area contact, and condition of the absorptive surface may increase or decrease the amount of drug absorbed (large surfaces absorb rapidly) o Absorption from GI depends on gastric volume, GI pH, gastric emptying time, intestinal transit rate, gastric motility, and GI enzyme level o Quality of blood flow to site of absorption effects how much of drug is absorbed Life Span and Gender o Ingested solids versus liquids empty more slowly from women’s stomachs o Gastric acidity lower in women o Women have lower gastric levels of alcohol dehydrogenase Lifestyle, Diet, and Habits o Diet may stimulate digestive enzymes and alter gastric and intestinal mucosa 1 Pharmacology Chapters 4 & 5 Exam 1 o Drugs ingested with food absorbed slower o Some drugs and food form complexes that cannot pass through mucosal lining of the GI o Some drugs are destroyed by the high acidity and peptic activity of gastric digestive enzymes Distribution Depends on 3 factors: blood flow to tissues, drug’s ability to leave the blood, and the drug’s ability to enter cells Drug is ransported to the tissues and cells through the circulatory system Most drugs do not produce effect while in blood ProteinBound Drugs (Albumin) Protein binding of drugs affects distribution of a drug When the drug is protein bound, it cannot pass through capillary walls The bonds will dissolve in time and the drug molecules will become free and active Drug dosages are calculated based on the protein binding characteristics of the drug When the pt. has lower than expected protein levels, the distribution of the drug is altered Highlyprotein bound drugs=low amount of free drugs (may have to give more of the drug for it to work) Highly protein bound drugs given to pt. with liver failure… the drug will reach the target cells more quickly which could result in a toxic effect. o Pts with liver failure have lower levels of albumin in their blood than pts without liver failure; therefore, the drug will reach the target cells more quickly, which could lead to a toxic effect o Remember that all recommended drug dosages are calculated based on a pt with normal protein levels BloodBrain Barrier Capillary bed that services the brain is different from other capillary beds Instead of wide spaces between cells these are tightly packed together This structure prevents drug molecules, and other foreign substances, from passing through and entering the brain Purpose is to keep toxins and poisons from reaching the brain At times this will prevent treatment of a problem Alcohol can pass through it Placental Membrane Separates the maternal circulation from the fetal circulation Not like the bloodbrain barrier Any drug that can pass through a membrane can pass through the placenta In order to pass through the placenta, a drug must be lipophilic, not ionized, and not protein bound CORE PATIENT VARIABLES AND DISTRIBUTION: Health Status: o Hepatic dysfunction decreases manufacturing of albumin o Hypoalbuminemia, hepatic disease, and renal disease decrease extent of drug binding (acidic and neutral drugs) Life Span and Gender o At birth: bloodbrain barrier not fully developed causing increased vulnerability of infant to CNS poisons and greater sensitivity to drugs acting on brain in comparison with adults 2 Pharmacology Chapters 4 & 5 Exam 1 o In pregnant women and fetuses: some drugs may be distributed to and bind with receptor sites in such a way that tissues may be adversely affects (bones and teeth) o Blood albumins are not thought to possess gender dependent predilection, although levels of some globulin proteins are lower in women Lifestyle, Diet, and Habits o Poor dietary intake of necessary nutrients and proteins contribute to low circulating albumin levels increasing displacement of drugs that are normally highly protein bound into circulation o Alcohol abuse directly affects liver and its ability to function normally o Obesity significantly influences distribution of drugs that are highly lipophilic b/c drug will move to fall cells Metabolism Metabolism of drugs occurs primarily in the liver Anything that impairs liver functioning decreases the ability to metabolize drugs When a drug is metabolized, it is changed from their original form to a new form o Aka biotransformation Usually metabolized from lipophilic to hydrophilic Metabolites Product of metabolism Generally an inactive form of the metabolized drug Can convert a drug that has little of no therapeutic effect in its original form into the active form Drugs that are inactive until metabolized into an active form are called prodrugs An active metabolite may cause a different and potentially harmful effect FirstPass Effect oral drugs Metabolism occurs at different rates for different drugs Percentage of the drug that is metabolized each time the drug circulates, or passes through the liver is the same, but the total number of drug molecules that are metabolized will be different Drugs that are highly metabolized lose much of their effectiveness during this first pass through the liver This loss of effectiveness is called the firstpass effect Drugs that experience a high firstpass effect may need higher oral doses to achieve a therapeutic level of circulating drug P450 System Metabolism is primarily achieved by specific liver enzymes Those microsomal enzymes are called the cytochrome P450 systems The enzyme CYP3A4 is the most common and responsible for the metabolism of most drugs Some drugs inhibit or induce the P450 system, altering metabolism of other drugs When a large quantity of one of these enzymes is present, more metabolism can occur through this pathway This increase in metabolism rapidly decreases the amount of circulating drug CORE DRUG VARIABLES AND METABOLISM: Life Span and Gender o Drug metabolism in patients whose enzymatic metabolic systems are either immature or functioning less efficiently is highly variable but is usually diminished (decreased metabolism increases risk for adverse effects) Lifestyle, Diet, and Habits: 3 Pharmacology Chapters 4 & 5 Exam 1 o Malnutrition may prolong drug effects as a result of poor hepatic microsomal metabolism o In obese people, phase II transformations tend to occur more rapidly, higher drug doses needed o Effects of drugs may be intensified if places patient at risk for anorexia, increased appetite, n/v, nutritional deficiencies, stomatitis, toxic reactions o Diet may contribute to individual variations in drug metabolism o Exposure to smoke and pesticides may cause more rapid metabolism of some drugs Environment: o Reduces partial pressure of o2 at higher altitudes may affect enzymatic reduction systems o Environmental pollutants may affect induction or inhibition of hepatic enzymes o Light is a key modulator in the regulation of metabolic pathways and in specific settings may affect drug response Excretion—process of removing a drug, or its metabolites, from the body Most common route is urine Diseases and pathophysiologic changes in the kidney decrease the effectiveness of the kidney in drug excretion Three processes involved in renal excretion: o Glomerular Filtration—most drug particles pass easily through the spaces of the capillary walls into the urine in the proximal tubule o Passive Tubular Reabsorption—the drug particles will try to move from the area of greater concentration to that of lesser concentration o Active Tubular Secretion—active transport systems in the renal tubule work to move some drugs from the blood into the urine Factors that Affect Renal Excretion Drug excretion can be increased if the pH of the urine encourages the drug to become an ion Overuse of the active transport system also affects excretion o As the system becomes overloaded, some of the drug particles will remain in the blood until they can be moved by the transport system Two drugs can be given together to slow deliberately the rate of excretion of one or both of the drugs **
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'