Pharmacology in Nursing and Medication Administration

Pharmacology in Pharmacology in Nursing and Nursing and Medication Medication AdministrationAdministration

.

Pharmacologic Pharmacologic ConceptsConcepts

Drug NamesDrug Names Chemical nameChemical name• Describes the drug’s Describes the drug’s

chemical composition and chemical composition and molecular structuremolecular structure

Generic nameGeneric name (nonproprietary name)(nonproprietary name)

• Name given by the United Name given by the United States Adopted States Adopted Name CouncilName Council

Trade nameTrade name (proprietary (proprietary name)name)

• The drug has a registered The drug has a registered trademark; use of the name trademark; use of the name restricted by the drug’s restricted by the drug’s patent owner patent owner (usually the manufacturer)(usually the manufacturer)

Drug Names Drug Names (cont'd)(cont'd)

Chemical nameChemical name• (+/-)-2-(p-isobutylphenyl) (+/-)-2-(p-isobutylphenyl)

propionic acidpropionic acid

Generic nameGeneric name• ibuprofenibuprofen

Trade nameTrade name• Motrin®, Advil®Motrin®, Advil®

Pharmacological Pharmacological Concepts: Concepts: ClassificationClassification

• Classification- Classification- Functional Class vs Functional Class vs Chemical ClassChemical Class

• Medication Medication classification indicates classification indicates the effect of the med on the effect of the med on the body system, the the body system, the symptom the med symptom the med relieves, or the med’s relieves, or the med’s desired effect (e.g. oral desired effect (e.g. oral hypoglycemics)hypoglycemics)

Pharmacological Pharmacological Concepts: Concepts: ClassificationClassification

• A medication may A medication may also be part of more also be part of more than one class than one class

• Aspirin is an Aspirin is an analgesic, analgesic, antipyretic, anti-antipyretic, anti-inflammatory, and inflammatory, and anti-plateletanti-platelet

Pharmacological Pharmacological Concepts: Concepts: Medication Medication FormsForms

• Medications are Medications are available in a variety of available in a variety of forms and preparationsforms and preparations

• The form of the med The form of the med will determine its route will determine its route of administrationof administration

• Composition of med is Composition of med is designed to enhance its designed to enhance its absorption & absorption & metabolismmetabolism

• Many meds are Many meds are available in several available in several formsforms

Medication Medication FormsForms

• TabletTablet• CapsuleCapsule• ElixirElixir• Enteric-coatedEnteric-coated• SuppositorySuppository• SuspensionSuspension• Transdermal patchTransdermal patch

PharmacokinetiPharmacokineticscs

• • The study of what The study of what the body does to the the body does to the drugdrug– AbsorptionAbsorption– DistributionDistribution– MetabolismMetabolism– ExcretionExcretion

PharmacodynamiPharmacodynamicscs

• • The study of what the The study of what the drug does to the bodydrug does to the body– The mechanism of drug The mechanism of drug

actions in living tissuesactions in living tissues

Figure 2-2 Phases of Drug Activity. (From McKenry LM, Salerno E: Mosby’s pharmacology in nursing—revised and updated, ed 21, St. Louis, 2003, Mosby.)

PharmacotherapeutiPharmacotherapeuticscs

The use of drugs and The use of drugs and the clinical indications the clinical indications for drugs to prevent for drugs to prevent and treat diseasesand treat diseases

Pharmacokinetics: Pharmacokinetics: AbsorptionAbsorption

• The rate at which a The rate at which a drug leaves its site drug leaves its site of administration, of administration, and the extent to and the extent to which absorption which absorption occursoccurs– BioavailabilityBioavailability– BioequivalentBioequivalent

Factors That Factors That Affect Affect AbsorptionAbsorption

• Administration route of Administration route of the drugthe drug

• Ability of Med to Ability of Med to DissolveDissolve

• Food or fluids Food or fluids administered with the administered with the drugdrug

• Body Surface AreaBody Surface Area• Status of the absorptive Status of the absorptive

surfacesurface• Rate of blood flow to the Rate of blood flow to the

small intestinesmall intestine• Lipid Solubility of MedLipid Solubility of Med• Status of GI motilityStatus of GI motility

Routes of Routes of Administration Administration

• A drug’s route of A drug’s route of administration administration affects the rate and affects the rate and extent of absorption extent of absorption of that drugof that drug– EnteralEnteral (GI tract) (GI tract)– ParenteralParenteral– TopicalTopical

Enteral RouteEnteral Route • Drug is absorbed Drug is absorbed into the systemic into the systemic circulation through circulation through the oral or gastric the oral or gastric mucosa, the small mucosa, the small intestine, or rectumintestine, or rectum– OralOral– SublingualSublingual– BuccalBuccal– RectalRectal

First-Pass EffectFirst-Pass Effect• The metabolism of a drug The metabolism of a drug

and its passage from the and its passage from the liver into the circulationliver into the circulation– A drug given via the oral A drug given via the oral

route may be extensively route may be extensively metabolized by the liver metabolized by the liver before reaching the before reaching the systemic circulation (high systemic circulation (high first-pass effect)first-pass effect)

– The same drug—given IV—The same drug—given IV—bypasses the liver, bypasses the liver, preventing the first-pass preventing the first-pass effect from taking place, effect from taking place, and more drug reaches the and more drug reaches the circulationcirculation

Box 2-1 Drug Routes and First-Pass Effects

Parenteral Parenteral RouteRoute

• Intravenous (fastest Intravenous (fastest delivery into the delivery into the blood circulation)blood circulation)

• IntramuscularIntramuscular• SubcutaneousSubcutaneous• IntradermalIntradermal• IntrathecalIntrathecal• IntraarticularIntraarticular

Topical RouteTopical Route • Skin (including Skin (including transdermal transdermal patches)patches)

• EyesEyes• EarsEars• NoseNose• Lungs (inhalation)Lungs (inhalation)• VaginaVagina

DistributionDistribution

The transport of a drug in The transport of a drug in the body by the the body by the bloodstream to its site of bloodstream to its site of actionaction• Protein-bindingProtein-binding• Water soluble vs. fat solubleWater soluble vs. fat soluble• Blood-brain barrierBlood-brain barrier• Areas of rapid distribution: Areas of rapid distribution: heart, liver, heart, liver,

kidneys, brainkidneys, brain• Areas of slow distribution: Areas of slow distribution: muscle, skin, fatmuscle, skin, fat

MetabolismMetabolism(Also Known As (Also Known As Biotransformation)Biotransformation)

The biologic The biologic transformation of a drug transformation of a drug into into an inactive metabolite, a an inactive metabolite, a more soluble compound, more soluble compound, or a more potent or a more potent metabolitemetabolite• Liver (main organ)Liver (main organ)• KidneysKidneys• LungsLungs• PlasmaPlasma• Intestinal mucosaIntestinal mucosa

Metabolism/Metabolism/Biotransformation (cont'd)Biotransformation (cont'd)

Delayed drug Delayed drug metabolism results metabolism results in:in:

• Accumulation of drugsAccumulation of drugs• Prolonged action of the Prolonged action of the

drugsdrugs

Stimulating drug Stimulating drug metabolism causes:metabolism causes:

• Diminished Diminished pharmacologic effectspharmacologic effects

ExcretionExcretion The elimination of The elimination of drugs from the bodydrugs from the body

• Kidneys (main organ)Kidneys (main organ)• LiverLiver• BowelBowel

– Biliary excretionBiliary excretion– Enterohepatic circulationEnterohepatic circulation

• 1.1. You are caring for a client who has diabetes You are caring for a client who has diabetes complicated by kidney disease. You will need to make a complicated by kidney disease. You will need to make a detailed assessment when administering medications detailed assessment when administering medications because this client may experience problems with:because this client may experience problems with:

• A. A. AbsorptionAbsorption• B. B. BiotransformationBiotransformation• C. C. DistributionDistribution• D. D. ExcretionExcretion

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PharmacodynamiPharmacodynamicscs

• Study of the Study of the mechanism of drug mechanism of drug actions in living actions in living tissuetissue

• Drug-induced Drug-induced alterations to normal alterations to normal physiologic functionphysiologic function

• Positive change-Positive change-Therapeutic effect-Therapeutic effect-Goal of therapyGoal of therapy

Mechanism of Mechanism of ActionAction

• Ways in which a Ways in which a drug can produce a drug can produce a therapeutic effecttherapeutic effect

• The effects that a The effects that a particular drug has particular drug has depends on the cells depends on the cells or organ targeted by or organ targeted by the drugthe drug

• Once the drug hits Once the drug hits its “site of action” it its “site of action” it can modify the rate can modify the rate at which a cell or at which a cell or tissue functionstissue functions

Mechanism of Mechanism of ActionAction

• Receptor InteractionReceptor Interaction

• Enzyme InteractionEnzyme Interaction

• Non-Specific Non-Specific

InteractionInteraction

Receptor Receptor InteractionInteraction

• Drug structure is essentialDrug structure is essential

• Involves the selective Involves the selective joining of drug molecule joining of drug molecule with a reactive site on the with a reactive site on the cell surface that elicits a cell surface that elicits a biological effectbiological effect

• Receptor is the reactive Receptor is the reactive site on a cell or tissuesite on a cell or tissue

• Once the substance binds Once the substance binds to and interacts with the to and interacts with the receptor, a pharmacologic receptor, a pharmacologic response is producedresponse is produced

Receptor Receptor InteractionInteraction

• Affinity- degree to Affinity- degree to which a drug binds with which a drug binds with a receptora receptor

• The drug with the best The drug with the best “fit” or affinity will elicit “fit” or affinity will elicit the best responsethe best response

• Drug can mimic body’s Drug can mimic body’s endogenous substances endogenous substances that normally bind to that normally bind to receptor sitereceptor site

• Drugs that bind to Drugs that bind to receptors interact with receptors interact with receptors in different receptors in different ways to either ways to either blockblock or or elicitelicit a response a response

Receptor Receptor InteractionInteraction

• Agonist-Drug binds Agonist-Drug binds to receptor-there is a to receptor-there is a response response (Adrenergic Agents)(Adrenergic Agents)

• Antagonist-drug Antagonist-drug binds to receptor-no binds to receptor-no response-prevents response-prevents binding of agonists binding of agonists (Alpha & Beta (Alpha & Beta Blockers)Blockers)

Enzyme Enzyme InteractionInteraction

• Enzymes are substances Enzymes are substances that catalyze nearly that catalyze nearly every biochemical every biochemical reaction in a cellreaction in a cell

• Drugs can interact with Drugs can interact with enzyme systems to alter enzyme systems to alter a responsea response

• Inhibits action of Inhibits action of enzymes-enzyme is enzymes-enzyme is “fooled” into binding to “fooled” into binding to drug instead of target drug instead of target cellcell

• Protects target cell from Protects target cell from enzyme’s action (ACE enzyme’s action (ACE Inhibitors)Inhibitors)

Non-Specific Non-Specific InteractionInteraction

• Not involving a receptor Not involving a receptor site or alteration in site or alteration in enzyme functionenzyme function

• Main site of action is Main site of action is cell membrane or cell membrane or cellular processcellular process

• Drugs will physically Drugs will physically interfere or chemically interfere or chemically alter cell processalter cell process

• Final product is altered Final product is altered causing defect or cell causing defect or cell deathdeath

• Cancer drugs, Cancer drugs, AntibioticsAntibiotics

The nurse is giving a medication that has a high first-pass effect. The physician has changed the route from IV to PO. The nurse expects the oral dose to be:

1.Higher because of the first-pass effect.2.Lower because of the first-pass effect.3.The same as the IV dose.4.Unchanged.

. A patient is complaining of severe pain and has orders for morphine sulfate. The nurse knows that the route that would give the slowest pain relief would be which route?

1. IV2. IM3.SC4.PO

Type of Type of Medication Medication ActionAction

• Therapeutic EffectTherapeutic Effect• Side EffectsSide Effects• Adverse EffectsAdverse Effects• Toxic EffectToxic Effect• Idiosyncratic ReactionsIdiosyncratic Reactions• Allergic ReactionAllergic Reaction• Medication InteractionsMedication Interactions• Iatrogenic ResponseIatrogenic Response

Therapeutic Therapeutic EffectEffect

• The expected or The expected or predictable predictable physiological physiological response a response a medication causesmedication causes

• A single med can A single med can have several have several therapeutic effects therapeutic effects (Aspirin)(Aspirin)

• It is important for It is important for the nurse to know the nurse to know why med is being why med is being prescribedprescribed

Side EffectsSide Effects

• Unintended secondary Unintended secondary effects a medication effects a medication predictably will causepredictably will cause

• May be harmless or May be harmless or seriousserious

• If side effects are serious If side effects are serious enough to negate the enough to negate the beneficial effect of meds beneficial effect of meds therapeutic action, it therapeutic action, it may be D/C’dmay be D/C’d

• People may stop taking People may stop taking medications because of medications because of the side effectsthe side effects

Adverse EffectsAdverse Effects • Undesirable response of Undesirable response of a medicationa medication

• Unexpected effects of Unexpected effects of drug not related to drug not related to therapeutic effecttherapeutic effect

• Must be reported to Must be reported to FDAFDA

• Can be a side effect or Can be a side effect or a harmful effecta harmful effect

• Can be categorized as Can be categorized as pharmacologic, pharmacologic, idiosyncratic, idiosyncratic, hypersensitivity, or hypersensitivity, or drug interactiondrug interaction

Adverse EffectsAdverse Effects • Adverse Drug EventsAdverse Drug Events

• Adverse Drug Adverse Drug Reactions (ADR)Reactions (ADR)

Toxic EffectToxic Effect• May develop after May develop after

prolonged intake or prolonged intake or when a med when a med accumulates in the accumulates in the blood because of blood because of impaired metabolism or impaired metabolism or excretion, or excessive excretion, or excessive amount takenamount taken

• Toxic levels of opioids Toxic levels of opioids can cause can cause resp.depressionresp.depression

• Antidotes available to Antidotes available to reverse effectsreverse effects

Idiosyncratic Idiosyncratic ReactionsReactions

• Unpredictable effects-Unpredictable effects-overreacts or under overreacts or under reacts to a medication or reacts to a medication or has a reaction different has a reaction different from normalfrom normal

• Genetically determined Genetically determined abnormal responseabnormal response

• Idiosyncratic drug Idiosyncratic drug reactions are usually reactions are usually caused by abnormal caused by abnormal levels of drug-levels of drug-metabolizing enzymes metabolizing enzymes (deficiency or (deficiency or overabundance)overabundance)

Allergic Allergic ReactionReaction

• Unpredictable response Unpredictable response to a medicationto a medication

• Makes up greater than Makes up greater than 10% of all medication 10% of all medication reactionsreactions

• Client may become Client may become sensitized sensitized immunologically to the immunologically to the initial dose, repeated initial dose, repeated administration causes administration causes an allergic response to an allergic response to the med, chemical the med, chemical preservative or a preservative or a metabolitemetabolite

Allergic ReactionAllergic Reaction• Medication acts as an Medication acts as an

antigen triggering the antigen triggering the release of the body’s release of the body’s antibodiesantibodies

• May be mild or severeMay be mild or severe• Among the different Among the different

classes of meds, classes of meds, antibiotics cause the antibiotics cause the highest incidence of highest incidence of allergic reactionallergic reaction

• Severe reaction-Severe reaction-Anaphylactic reactionAnaphylactic reaction

• Mild reaction-hives, Mild reaction-hives, rash, pruritisrash, pruritis

• 2. 2. A postoperative client is receiving morphine A postoperative client is receiving morphine sulfate via a PCA. The nurse assesses that the client’s sulfate via a PCA. The nurse assesses that the client’s respirations are depressed. The effects of the morphine respirations are depressed. The effects of the morphine sulfate can be classified as: sulfate can be classified as:

• A. A. AllergicAllergic• B. B. IdiosyncraticIdiosyncratic• C. C. TherapeuticTherapeutic• D. D. ToxicToxic

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Other Drug Other Drug ReactionsReactions

• Teratogenic-Teratogenic-Structural effect in Structural effect in unborn fetus unborn fetus (thalidomide)(thalidomide)

• Carcinogenic-Causes Carcinogenic-Causes cancercancer

• Mutagenic- Changes Mutagenic- Changes genetic composition genetic composition (radiation, (radiation, chemicals)chemicals)

Drug Drug InteractionsInteractions

• Occurs when one med Occurs when one med modifies the action of modifies the action of another another

• Common in people Common in people taking several taking several medications at oncemedications at once

• One med may One med may potentiate or diminish potentiate or diminish the action of another the action of another or alter the way it is or alter the way it is absorbed, absorbed, metabolized or metabolized or eliminatedeliminated

• Warfarin and Warfarin and AmiodaroneAmiodarone

Iatrogenic Iatrogenic ResponsesResponses

• Unintentional adverse Unintentional adverse effects that occur during effects that occur during therapytherapy

• Treatment-Induced Treatment-Induced Dermatologic-rash, Dermatologic-rash, hives, acnehives, acne

• Renal Damage-Renal Damage-Aminoglycoside Aminoglycoside antibiotics, NSAIDS, antibiotics, NSAIDS, contrast mediumcontrast medium

• Blood Dyscrasias- Blood Dyscrasias- Destruction of blood Destruction of blood cells (Chemotherapy)cells (Chemotherapy)

• Hepatic Toxicity-Hepatic Toxicity-Elevated liver enzymes Elevated liver enzymes (hepatitis-like (hepatitis-like symptoms)symptoms)

Synergistic Synergistic EffectEffect

• Effect of 2 meds Effect of 2 meds combined is greater than combined is greater than the meds given the meds given separatelyseparately

• Alcohol & Antihistamines, Alcohol & Antihistamines, antidepressants, antidepressants, barbiturates, narcoticsbarbiturates, narcotics

• Not always undesirable, Not always undesirable, physician may combine physician may combine meds to create an meds to create an interaction that will have interaction that will have beneficial effects beneficial effects (Vasodilators & diuretics (Vasodilators & diuretics to control high BP)to control high BP)

Medication Medication Dose ResponsesDose Responses

• Except when Except when administered IV, meds administered IV, meds take time to enter take time to enter bloodstreambloodstream

• The quantity & The quantity & distribution of med in distribution of med in different body different body compartments change compartments change constantlyconstantly

• Goal is to keep constant Goal is to keep constant blood level within a safe blood level within a safe therapeutic rangetherapeutic range

• Repeated doses are Repeated doses are required to achieve a required to achieve a constant therapeutic constant therapeutic concentrationconcentration of a med of a med because a portion of med because a portion of med is always being excretedis always being excreted

Medication Medication Dose ResponsesDose Responses

• Serum Half-Life:Time it Serum Half-Life:Time it takes for excretion takes for excretion processes to lower the processes to lower the serum medication serum medication concentration by ½concentration by ½

• Regular fixed doses Regular fixed doses must be given to must be given to maintain therapeutic maintain therapeutic concentrationconcentration

• Dosage schedules set by Dosage schedules set by institutions (TID, q8h, institutions (TID, q8h, HS, AC, STAT, PRN)HS, AC, STAT, PRN)

• Peak & Trough levelsPeak & Trough levels• Therapeutic drug Therapeutic drug

monitoringmonitoring

Half-lifeHalf-life • The time it takes for The time it takes for one half of the original one half of the original amount of a drug in the amount of a drug in the body to be removedbody to be removed

• A measure of the rate A measure of the rate at which drugs are at which drugs are removed from the bodyremoved from the body

Onset, Peak, Onset, Peak, and Durationand Duration

OnsetOnset• The time it takes for the The time it takes for the

drug to elicit a drug to elicit a therapeutic responsetherapeutic response

PeakPeak• The time it takes for a The time it takes for a

drug to reach its drug to reach its maximum therapeutic maximum therapeutic response response

DurationDuration• The time a drug The time a drug

concentration is sufficient concentration is sufficient to elicit a therapeutic to elicit a therapeutic responseresponse

Pharmacotherapeutics: Types Pharmacotherapeutics: Types of Therapiesof Therapies

• Acute therapyAcute therapy• Maintenance therapyMaintenance therapy• Supplemental Supplemental

therapytherapy• Palliative therapyPalliative therapy• Supportive therapySupportive therapy• Prophylactic therapyProphylactic therapy

MonitoringMonitoring • The effectiveness of The effectiveness of the drug therapy the drug therapy must be evaluatedmust be evaluated

• One must be familiar One must be familiar with the drug’s:with the drug’s:– Intended therapeutic Intended therapeutic

action (beneficial)action (beneficial)– Unintended but Unintended but

potential side effects potential side effects (predictable, adverse (predictable, adverse reactions)reactions)

Monitoring Monitoring (cont'd)(cont'd)

• • Therapeutic indexTherapeutic index– – The ratio between a The ratio between a drug’s therapeutic drug’s therapeutic benefits and its toxic benefits and its toxic effectseffects

Monitoring Monitoring (cont'd)(cont'd)

Interactions may occur Interactions may occur with other drugs or with other drugs or foodfood• Drug interactions: the Drug interactions: the alteration of action of alteration of action of a drug by: a drug by:

– Other prescribed Other prescribed drugsdrugs

– Over-the-counter Over-the-counter medicationsmedications

– Herbal therapiesHerbal therapies

Monitoring Monitoring (cont'd)(cont'd)

• • Drug interactionsDrug interactions– – Additive effectAdditive effect

– – Synergistic effectSynergistic effect

– – Antagonistic effectAntagonistic effect

– – IncompatibilityIncompatibility

Monitoring Monitoring (cont'd)(cont'd)

• Medication Medication misadventuresmisadventures– Adverse drug eventsAdverse drug events– Adverse drug Adverse drug

reactions reactions – Medication errorsMedication errors

Monitoring Monitoring (cont'd)(cont'd)

Some adverse drug Some adverse drug reactions are reactions are classified as side classified as side effectseffects

• Expected, well-known Expected, well-known reactions that result in reactions that result in little or no change in little or no change in patient managementpatient management

• Predictable frequencyPredictable frequency• The effect’s intensity The effect’s intensity

and occurrence are and occurrence are related to the size of related to the size of the dosethe dose

Adverse Drug Adverse Drug ReactionReaction

An adverse outcome An adverse outcome of drug therapy in of drug therapy in which a patient is which a patient is harmed in some wayharmed in some way

• Pharmacologic Pharmacologic reactionsreactions

• Idiosyncratic reactionsIdiosyncratic reactions• Hypersensitivity Hypersensitivity

reactionsreactions• Drug interactionsDrug interactions

Other Drug-Other Drug-Related EffectsRelated Effects

• TeratogenicTeratogenic• MutagenicMutagenic• CarcinogenicCarcinogenic

ToxicologyToxicology The study of poisons The study of poisons and unwanted and unwanted responses to responses to therapeutic agentstherapeutic agents

Table 2-9 Common Poisons and Antidotes

The Nursing The Nursing Process Process

• AssessmentAssessment• Nursing diagnosisNursing diagnosis• Planning (with Planning (with

outcome criteria)outcome criteria)• ImplementationImplementation• EvaluationEvaluation

The Nursing The Nursing Process (cont'd)Process (cont'd)

AssessmentAssessment• Data collection Data collection

– Subjective, objectiveSubjective, objective– Data collected on the Data collected on the

patient, drug, patient, drug, environmentenvironment

• Medication historyMedication history• Nursing assessmentNursing assessment• Physical assessmentPhysical assessment• Data analysisData analysis

The “Seven The “Seven Rights”Rights”

• Right drugRight drug• Right doseRight dose• Right timeRight time• Right routeRight route• Right patientRight patient• Right to refuseRight to refuse• Right Right

documentationdocumentation

Another “Right”—Constant Another “Right”—Constant System AnalysisSystem Analysis

• A “double-check”A “double-check”• The entire “system” of The entire “system” of

medication medication administrationadministration

• Ordering, dispensing, Ordering, dispensing, preparing, preparing, administering, administering, documentingdocumenting

• Involves the physician, Involves the physician, nurse, nursing unit, nurse, nursing unit, pharmacy department, pharmacy department, and patient educationand patient education

Other Other “Rights”“Rights”

• Proper drug storageProper drug storage• Proper Proper

documentationdocumentation• Accurate dosage Accurate dosage

calculationcalculation• Accurate dosage Accurate dosage

preparationpreparation• Careful checking of Careful checking of

transcription of transcription of ordersorders

• Patient safetyPatient safety

Other Other “Rights” “Rights” (cont'd)(cont'd)

• Close consideration Close consideration of special situationsof special situations

• Prevention and Prevention and reporting of reporting of medication errorsmedication errors

• Patient teachingPatient teaching• Monitoring for Monitoring for

therapeutic effects, therapeutic effects, side effects, toxic side effects, toxic effectseffects

• Refusal of medicationRefusal of medication

EvaluationEvaluation •• Ongoing part of the Ongoing part of the nursing processnursing process

• Determining the Determining the status of the goals status of the goals and and outcomes of careoutcomes of care

• Monitoring the Monitoring the patient’s response to patient’s response to drug therapydrug therapy– Expected and Expected and

unexpected unexpected responsesresponses

The day shift charge nurse is making rounds. A patient tells the nurse that the night shift nurse never gave him his medication, which was due at 11 PM. What should the nurse do first to determine whether the medication was given?

1. Call the night nurse at home.2. Check the Medication Administration Record.3. Call the pharmacy.4. Review the nurse’s notes.

The patient’s Medication Administration Record lists two antiepileptic medications that are due at 0900, but the patient is NPO for a barium study. The nurse’s coworker suggests giving the medications via IV because the patient is NPO. What should the nurse do?

1. Give the medications PO with a small sip of water.2. Give the medications via the IV route because the

patient is NPO.3. Hold the medications until after the test is

completed.4. Call the physician to clarify the instructions.

Life Span Life Span ConsiderationsConsiderations

Life Span Life Span ConsiderationsConsiderations

• PregnancyPregnancy• Breast-feedingBreast-feeding• NeonatalNeonatal• PediatricPediatric• GeriatricGeriatric

PregnancyPregnancy • First trimester is the First trimester is the period of greatest period of greatest danger for drug-danger for drug-induced induced developmental developmental defectsdefects

• Drugs diffuse across Drugs diffuse across the placentathe placenta

• FDA pregnancy FDA pregnancy safety categoriessafety categories

Table 3-1 Table 3-1 Pregnancy safety Pregnancy safety categoriescategories

Breast-feedingBreast-feeding • Breast-fed infants Breast-fed infants are at risk for are at risk for exposure to drugs exposure to drugs consumed by the consumed by the mothermother

• Consider risk-to-Consider risk-to-benefit ratiobenefit ratio

Table 3-2 Classification Table 3-2 Classification of young patientsof young patients

Pediatric Considerations: Pediatric Considerations: PharmacokineticsPharmacokinetics

• AbsorptionAbsorption– Gastric pH less acidicGastric pH less acidic– Gastric emptying is Gastric emptying is

slowedslowed– Topical absorption Topical absorption

faster through the faster through the skinskin

– Intramuscular Intramuscular absorption faster and absorption faster and irregularirregular

Pediatric Considerations: Pediatric Considerations: Pharmacokinetics (cont'd)Pharmacokinetics (cont'd)

• DistributionDistribution– TBW 70% to 80% in TBW 70% to 80% in

full-term infants, 85% full-term infants, 85% in premature newborns, in premature newborns, 64% in children 1 to 64% in children 1 to 12 years of age12 years of age

– Greater TBW means fat Greater TBW means fat content is lowercontent is lower

– Decreased level of Decreased level of protein binding protein binding

– Immature blood-brain Immature blood-brain barrierbarrier

Pediatric Considerations: Pediatric Considerations: Pharmacokinetics (cont'd)Pharmacokinetics (cont'd)

• MetabolismMetabolism– Liver immature, does Liver immature, does

not produce enough not produce enough microsomal enzymesmicrosomal enzymes

– Older children may Older children may have increased have increased metabolism, requiring metabolism, requiring higher doseshigher doses

– Other factorsOther factors

Pediatric Pediatric Considerations: Considerations: Pharmacokinetics Pharmacokinetics (cont'd)(cont'd) • ExcretionExcretion

– Kidney immaturity Kidney immaturity affects glomerular affects glomerular filtration rate and filtration rate and tubular secretiontubular secretion

– Decreased perfusion Decreased perfusion rate of the kidneysrate of the kidneys

Summary of Summary of Pediatric Pediatric ConsiderationsConsiderations • Skin is thin and permeableSkin is thin and permeable

• Stomach lacks acid to kill Stomach lacks acid to kill bacteriabacteria

• Lungs lack mucus barriersLungs lack mucus barriers• Body temperatures poorly Body temperatures poorly

regulated and dehydration regulated and dehydration occurs easilyoccurs easily

• Liver and kidneys are Liver and kidneys are immature, impairing drug immature, impairing drug metabolism and excretionmetabolism and excretion

Methods of Dosage Methods of Dosage Calculation for Pediatric Calculation for Pediatric PatientsPatients • Body weight dosage Body weight dosage

calculationscalculations

• Body surface area Body surface area methodmethod

Geriatric Geriatric ConsiderationsConsiderations

• Geriatric: older than Geriatric: older than age 65age 65– Healthy People 2010: Healthy People 2010:

older than age 55older than age 55

• Use of OTC Use of OTC medicationsmedications

• PolypharmacyPolypharmacy

Table 3-4 Physiologic changes in the Table 3-4 Physiologic changes in the geriatric patientgeriatric patient

Geriatric Considerations: Geriatric Considerations: PharmacokineticsPharmacokinetics

• AbsorptionAbsorption– Gastric pH less acidicGastric pH less acidic– Slowed gastric emptyingSlowed gastric emptying– Movement through GI Movement through GI

tract slowertract slower– Reduced blood flow to Reduced blood flow to

the GI tractthe GI tract– Reduced absorptive Reduced absorptive

surface area due to surface area due to flattened intestinal villiflattened intestinal villi

Geriatric Considerations: Geriatric Considerations: Pharmacokinetics (cont'd)Pharmacokinetics (cont'd)

• DistributionDistribution– TBW percentages TBW percentages

lowerlower– Fat content increasedFat content increased– Decreased production Decreased production

of proteins by the of proteins by the liver, resulting in liver, resulting in decreased protein decreased protein binding of drugsbinding of drugs

Geriatric Considerations: Geriatric Considerations: Pharmacokinetics (cont'd)Pharmacokinetics (cont'd)

• MetabolismMetabolism– Aging liver produces Aging liver produces

less microsomal less microsomal enzymes, affecting enzymes, affecting drug metabolismdrug metabolism

– Reduced blood flow Reduced blood flow to the liverto the liver

Geriatric Considerations: Geriatric Considerations: Pharmacokinetics (cont'd)Pharmacokinetics (cont'd)

• ExcretionExcretion– Decreased glomerular Decreased glomerular

filtration ratefiltration rate– Decreased number of Decreased number of

intact nephronsintact nephrons

Geriatric Considerations: Geriatric Considerations: Problematic MedicationsProblematic Medications

• AnalgesicsAnalgesics• AnticoagulantsAnticoagulants• AnticholinergicsAnticholinergics• AntihypertensivesAntihypertensives• DigoxinDigoxin• Sedatives and Sedatives and

hypnoticshypnotics• Thiazide diureticsThiazide diuretics

Legal, Ethical, Legal, Ethical, and Culturaland CulturalConsiderationConsiderationss

U.S. Drug U.S. Drug LegislationLegislation

• 1906: Federal Food 1906: Federal Food and Drug Actand Drug Act

• 1912: Sherley 1912: Sherley Amendment (to the Amendment (to the Federal Food and Federal Food and Drug Act of 1906)Drug Act of 1906)

• 1914: Harrison 1914: Harrison Narcotic ActNarcotic Act

• 1938: Federal Food, 1938: Federal Food, Drug, and Cosmetic Drug, and Cosmetic Act (revision of 1906 Act (revision of 1906 Act)Act)

U.S. Drug U.S. Drug Legislation Legislation (cont'd)(cont'd) • 1951: Durham-1951: Durham-

Humphrey Humphrey Amendment (to the Amendment (to the 1938 act)1938 act)

• 1962: Kefauver-1962: Kefauver-Harris Amendment Harris Amendment (to the 1938 act)(to the 1938 act)

• 1970: Controlled 1970: Controlled Substance ActSubstance Act

U.S. Drug U.S. Drug Legislation Legislation (cont'd)(cont'd) • 1983: Orphan Drug 1983: Orphan Drug

ActAct

• 1991: Accelerated 1991: Accelerated drug approvaldrug approval

New Drug New Drug DevelopmentDevelopment

• Investigational new Investigational new drug (IND) drug (IND) applicationapplication

• Informed consentInformed consent• Investigational drug Investigational drug

studiesstudies• Expedited drug Expedited drug

approvalapproval

U.S. FDA Drug U.S. FDA Drug Approval ProcessApproval Process • Preclinical Preclinical

investigational drug investigational drug studiesstudies

• Clinical phases of Clinical phases of investigational drug investigational drug studiesstudies– Phase IPhase I– Phase IIPhase II– Phase IIIPhase III– Phase IVPhase IV

Ethical Nursing Ethical Nursing PracticePractice

• American Nurses American Nurses Association (ANA) Association (ANA) Code of Ethics for Code of Ethics for NursesNurses

Cultural Cultural ConsiderationsConsiderations

• Assess the influence of Assess the influence of a patient’s cultural a patient’s cultural beliefs, values, and beliefs, values, and customscustoms

• Drug polymorphismDrug polymorphism• Compliance level with Compliance level with

therapytherapy• Environmental Environmental

considerationsconsiderations• Genetic factorsGenetic factors• Varying responses to Varying responses to

specific agentsspecific agents

Cultural Cultural AssessmentAssessment

• Health beliefs and Health beliefs and practicespractices

• Past uses of Past uses of medicinemedicine

• Folk remediesFolk remedies• Home remediesHome remedies• Use of Use of

nonprescription nonprescription drugs and herbal drugs and herbal remediesremedies

• OTC treatmentsOTC treatments

Cultural Cultural Assessment Assessment (cont'd)(cont'd) • Usual response to Usual response to

treatmenttreatment• Responsiveness to Responsiveness to

medical treatmentmedical treatment• Religious practices Religious practices

and beliefsand beliefs• Dietary habitsDietary habits

Medication Medication Errors:Errors:Preventing Preventing and and RespondingResponding

Medication Medication MisadventuresMisadventures

• Medication errors Medication errors (MEs)(MEs)

• Adverse drug events Adverse drug events (ADEs)(ADEs)

• Adverse drug Adverse drug reactions (ADRs)reactions (ADRs)

Medication Medication Misadventures Misadventures (cont'd)(cont'd)

• By definition, all By definition, all ADRs are also ADEsADRs are also ADEs

• But all ADEs are not But all ADEs are not ADRsADRs

• Two types of ADRsTwo types of ADRs– Allergic reactionsAllergic reactions– Idiosyncratic Idiosyncratic

reactionsreactions

Medication Medication ErrorsErrors

• PreventablePreventable• Common cause of Common cause of

adverse health care adverse health care outcomesoutcomes

• Effects can range from Effects can range from no significant effect to no significant effect to directly causing directly causing disability or deathdisability or death

Box 5-1 Common classes of medications Box 5-1 Common classes of medications involved in serious errorsinvolved in serious errors

• http://www.usp.org/pdf/EN/patientSafety/ismpAbbreviations.pdf

Preventing Preventing Medication ErrorsMedication Errors

• Minimize verbal or Minimize verbal or telephone orderstelephone orders– Repeat order to Repeat order to

prescriberprescriber– Spell drug name aloudSpell drug name aloud– Speak slowly and clearlySpeak slowly and clearly

• List indication next to List indication next to each ordereach order

• Avoid medical Avoid medical shorthand, including shorthand, including abbreviations and abbreviations and acronymsacronyms

Preventing Preventing Medication Errors Medication Errors (cont'd)(cont'd) • Never assume anything Never assume anything

about items not about items not specified in a drug order specified in a drug order (i.e., route)(i.e., route)

• Do not hesitate to Do not hesitate to question a medication question a medication order for any reason order for any reason when in doubtwhen in doubt

• Do not try to decipher Do not try to decipher illegibly written orders; illegibly written orders; contact prescriber for contact prescriber for clarificationclarification

Preventing Preventing Medication Errors Medication Errors (cont'd)(cont'd) • NEVER use “trailing NEVER use “trailing

zeros” with zeros” with medication ordersmedication orders

• Do not use 1.0 mg; Do not use 1.0 mg; use 1 mguse 1 mg

• 1.0 mg could be 1.0 mg could be misread as 10 mg, misread as 10 mg, resulting in a tenfold resulting in a tenfold dose increasedose increase

Preventing Preventing Medication Medication Errors (cont'd)Errors (cont'd) • ALWAYS use a ALWAYS use a

“leading zero” for “leading zero” for decimal dosagesdecimal dosages

• Do not use .25 mg; Do not use .25 mg; use 0.25 mguse 0.25 mg

• .25 mg may be .25 mg may be misread as 25 mgmisread as 25 mg

• ““.25” is sometimes .25” is sometimes called a “naked called a “naked decimal”decimal”

Preventing Preventing Medication Errors Medication Errors (cont'd)(cont'd) • Check medication Check medication

order and what is order and what is available while using available while using the “7 rights”the “7 rights”

• Take time to learn Take time to learn special administration special administration techniques of certain techniques of certain dosage formsdosage forms

Preventing Preventing Medication Errors Medication Errors (cont'd)(cont'd)

• Always listen to and Always listen to and honor any concerns honor any concerns expressed by patients expressed by patients regarding medicationsregarding medications

• Check patient Check patient allergies and allergies and identificationidentification

• Medication Medication ReconciliationReconciliation

Medication Medication ErrorsErrors • Possible consequences to Possible consequences to

nursesnurses• Reporting and responding Reporting and responding

to MEsto MEs– ADE monitoring programsADE monitoring programs– USPMERP (United States USPMERP (United States

Pharmacopeia Medication Pharmacopeia Medication Errors Reporting Program)Errors Reporting Program)

– MedWatch, sponsored by MedWatch, sponsored by the FDAthe FDA

– Institute for Safe Institute for Safe Medication Practices (ISMP)Medication Practices (ISMP)

• Notification of patient Notification of patient regarding MEsregarding MEs

• 3. 3. Nurses are legally required to document Nurses are legally required to document medications that are administered to clients. The nurse medications that are administered to clients. The nurse is mandated to document:is mandated to document:

• A. A. Medication before administering itMedication before administering it• B. B. Medication after administering itMedication after administering it• C. C. Rationale for administering the medicationRationale for administering the medication• D. D. Prescriber’s rationale for prescribing the Prescriber’s rationale for prescribing the

medicationmedication

35 - 129

• 4. 4. If a nurse experiences a problem reading a If a nurse experiences a problem reading a physician’s medication order, the most appropriate physician’s medication order, the most appropriate action will be to:action will be to:

• A. A. Call the physician to verify the order.Call the physician to verify the order.• B. B. Call the pharmacist to verify the order.Call the pharmacist to verify the order.• C. C. Consult with other nursing staff to verify the Consult with other nursing staff to verify the

order.order.• D. D. Withhold the medication until the physician Withhold the medication until the physician

makes rounds.makes rounds.

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Medication Medication AdministrationAdministration

Preparing for Preparing for Drug Drug AdministrationAdministration

• Check the “7 rights”Check the “7 rights”• Standard Precautions: Standard Precautions:

Wash your hands!Wash your hands!• Double-check if unsure Double-check if unsure

about anythingabout anything• Check for drug Check for drug

allergiesallergies• Prepare drugs for one Prepare drugs for one

patient at a timepatient at a time• Check three timesCheck three times

Preparing for Drug Preparing for Drug Administration Administration (cont'd)(cont'd)

• Check expiration datesCheck expiration dates• Check the patient’s Check the patient’s

identification (2 identification (2 identifiers)identifiers)

• Give medications on Give medications on timetime

• Explain medications to Explain medications to the patientthe patient

• Open the medications at Open the medications at the bedsidethe bedside

• Document the Document the medications given before medications given before going to the next patientgoing to the next patient

Drug Routes & Drug Routes & First Pass First Pass EffectsEffects

• First Pass Routes- First Pass Routes- Oral, RectalOral, Rectal

• Non-First Pass Non-First Pass Routes- Aural, Buccal, Routes- Aural, Buccal, Inhaled, Intraarterial, Inhaled, Intraarterial, Intramuscular, Intramuscular, Intranasal, Intranasal, Intraocular, Vaginal, Intraocular, Vaginal, Intravenous, Intravenous, Subcutaneous, Subcutaneous, Sublingual, Sublingual, TransdermalTransdermal

Oral RouteOral Route• Easiest, most Easiest, most

commonly usedcommonly used• Slower onset of Slower onset of

actionaction• More prolonged More prolonged

effecteffect• Preferred by clientsPreferred by clients• Sublingual Sublingual

AdministrationAdministration• Buccal Buccal

AdministrationAdministration

Enteral Enteral DrugsDrugs

• Giving oral medicationsGiving oral medications• Giving sublingual or Giving sublingual or

buccal medicationsbuccal medications• Liquid medicationsLiquid medications• Giving oral medications Giving oral medications

to infantsto infants• Administering drugs Administering drugs

through a nasogastric or through a nasogastric or gastrostomy tubegastrostomy tube

• Rectal administrationRectal administration

Parenteral RouteParenteral Route Injecting a Injecting a medication into body medication into body tissuestissues

• Subcutaneous (SQ)Subcutaneous (SQ)• Intramuscular (IM)Intramuscular (IM)• Intravenous (IV)Intravenous (IV)• Intradermal (ID)Intradermal (ID)• Advanced Advanced

techniques techniques

Parenteral Parenteral DrugsDrugs

• Never recap a used Never recap a used needle!needle!

• May recap an May recap an unused needle with unused needle with the “scoop method”the “scoop method”

• Prevention of Prevention of needlesticksneedlesticks

• Filter needlesFilter needles

Parenteral Parenteral Drugs Drugs (cont'd)(cont'd)

• Removing Removing medications from medications from ampulesampules

• Removing Removing medications from vialsmedications from vials

• Disposal of used Disposal of used needles and syringesneedles and syringes

• Needle SelectionNeedle Selection

InjectionsInjections • Needle angles for Needle angles for various injectionsvarious injections– Intramuscular (IM)Intramuscular (IM)– Subcutaneous (SC or Subcutaneous (SC or

SQ)SQ)– Intradermal (ID)Intradermal (ID)

• Z-track method for Z-track method for IM injectionsIM injections

• Air-lock techniqueAir-lock technique

Injection Injection TechniquesTechniques

• Intradermal injectionsIntradermal injections

• Subcutaneous Subcutaneous injectionsinjections– Insulin administrationInsulin administration– Anticoagulant Anticoagulant

administration administration (Heparin/Lovenox)(Heparin/Lovenox)

Injection Injection Techniques Techniques (cont'd)(cont'd)

• Intramuscular Intramuscular injectionsinjections– Ventrogluteal site Ventrogluteal site

(preferred)(preferred)– Vastus lateralis siteVastus lateralis site– Dorsogluteal siteDorsogluteal site– Deltoid siteDeltoid site

Preparing Preparing Intravenous Intravenous MedicationsMedications • Needleless systemsNeedleless systems

• Compatibility issuesCompatibility issues• Expiration datesExpiration dates• Mixing intravenous Mixing intravenous

piggyback (IVPB) piggyback (IVPB) medicationsmedications

• Labeling intravenous Labeling intravenous (IV) infusion bags (IV) infusion bags when adding when adding medicationsmedications

IntravenouIntravenous s MedicationMedicationss

• Adding medications to Adding medications to a primary infusion baga primary infusion bag

• IVPB medications IVPB medications (secondary line)(secondary line)

• IV push medications IV push medications (bolus)(bolus)– Through an IV lockThrough an IV lock– Through an existing IV Through an existing IV

infusioninfusion

Intravenous Intravenous Medications Medications (cont'd)(cont'd) • Volume-controlled Volume-controlled

administration setadministration set

• Using electronic Using electronic infusion pumpsinfusion pumps

• Patient-controlled Patient-controlled analgesia (PCA) analgesia (PCA) pumpspumps

Topical Topical DrugsDrugs

• Eye medicationsEye medications– DropsDrops– OintmentsOintments

• Ear dropsEar drops– AdultsAdults– Infant or child younger Infant or child younger

than 3 years of agethan 3 years of age

Topical Topical Drugs Drugs (cont'd)(cont'd)

• Nasal drugsNasal drugs– DropsDrops– SpraySpray

• Inhaled drugsInhaled drugs– Metered-dose Metered-dose

inhalersinhalers– Small-volume Small-volume

nebulizersnebulizers

Topical Topical Drugs Drugs (cont'd)(cont'd)

• Administering Administering medications to the medications to the skinskin– Lotions, creams, Lotions, creams,

ointments, powdersointments, powders– Transdermal patchesTransdermal patches

• Vaginal medicationsVaginal medications– Creams, foams, gelsCreams, foams, gels– SuppositoriesSuppositories