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UNIT 1 INTRODUCTION TO PHARMACOLOGY
Study of drugs and their action on the
living body
Medicinal agent that modifies body function
Used:To prevent ds. or pregnancyTo aid in dx or txTo restore or maintain functions
DRUG SOURCESAnimalsPlantsVitaminsMineralsSynthetics
SourcesAnimals
InsulinAdrenalinCortisoneThyroidHormones
SourcesPlants
Foxglove PoppyKelp MoldRoots BarkSeeds
SyntheticsLess expensive, more pure
NURSE’S ROLEKnowledge of:
Drug Action What is the expected responseTherapeutic Effect
Will this med achieve it’s goalPossible Adverse EffectsPatient Teaching
With every medThere is no excuse for administering a drug
without full knowledge
ASSESSMENT
ASSESSMENTOBJECTIVE
Physical assessment including: V.S. Weight Skin color
Diagnostic tests Drug levels in body (Dilantin, Dig) PT/INR LABS (BS/K)
SUBJECTIVE Allergy history (What kind of reaction) Complaints (?Pain)
PLANNING
PLANNINGSorting and analyzing the data to develop the plan of care and goalsWhat are you going to do based on your findings?
Planning pt / family teachingWhat needs to be taught?, When? Do you need handouts?
IMPLEMENTATION
IMPLEMENTATIONThis is the third step in the nursing process and is when we actually take actions that we planned.
This is execution of nursing actions
IMPLEMENTATIONPreparing and administering drugs
Always follow the six rightsAssessment of V.S. prior to administration
Actually check the VS, BSPatient teachingActually doing the teaching
EVALUATION
EVALUATIONHow the pt is responding to the intervention
Was goal met?
Reassessment of V.S., Pain level, etc.
Did BP respond?Did pain decrease?
PATIENT TEACHINGMost dramatic change in recent years
Patient has a right to know what med was given, they have right to refuse, and they have the right to generics
One of our most important rolesProvide written material, reinforce key points, document
DRUG LEGISLATION1906 Federal, Food, Drug and
Cosmetic Act
Began federal regulation Established safety guidelines;
required labeling, prohibited false claims and regulated advertising
National standards for drugs – USP (United States Pharmacopeia)Purity / Safety Concerns
1914 Harrison Narcotic ActFirst narcotic control
1938 – added FDA to enforce laws
1945, 1952, 1962 Amendments to Federal Food, Drug and Cosmetic Act
FDAFDA - Food and Drug Administration
part of Dept. Health and Human services
Federal agency to enforce federal drug laws including:Purity, labeling, testing, dispensing, safety,
advertisementFDA determines safety of drugs before
marketing, monitors development of new drugs
1970 CONTROLLED SUBSTANCE ACTStrict controls on manufacture and distribution of habit-forming drugs
Established 5 schedules of habit-forming drugs
Required gov’t programs to promote prevention & tx of drug dependence
Schedule 1 not accepted in US
Schedule I DrugsSchedule I Drugs
Schedule I drugs have a high tendency for abuse and have no accepted medical use. This schedule includes drugs such as Marijuana, Heroin, Ecstasy, LSD, and GHB. Recent activists have tried to change the schedule for Marijuana citing the possible medical benefits of the drug. Pharmacies do not sell Schedule I drugs, and they are not available with a prescription by physician.
Schedule II DrugsSchedule II Drugs
Schedule II drugs have a high tendency for abuse, may have an accepted medical use, and can produce dependency or addiction with chronic use. This schedule includes examples such as Cocaine, Opium, Morphine, Fentanyl, Amphetamines, and Methamphetamines. Schedule II drugs may be available with a prescription by a physician, but not all pharmacies may carry them. These drugs require more stringent records and storage procedures than drugs in Schedules III and IV.
Schedule III DrugsSchedule III Drugs
Schedule III drugs have less potential for abuse or addiction than drugs in the first two schedules and have a currently accepted medical use. Examples of Schedule III drugs include Anabolic steroids, Codeine, Ketamine, Hydrocodone with Aspirin, and Hydrocodone with Acetaminophen. Schedule III drugs may be available with a prescription, but not all pharmacies may carry them.
Schedule IV DrugsSchedule IV Drugs
Schedule IV drugs have a low potential for abuse, have a currently accepted medical use, has a low chance for addiction or limited addictive properties. Examples of Schedule IV drugs include Valium, Xanax, Phenobarbital, and Rohypnol (commonly known as the "date rape" drug). These drugs may be available with a prescription, but not all pharmacies may carry them.
Schedule V DrugsSchedule V Drugs
Schedule V drugs have a lower chance of abuse than Schedule IV drugs, have a currently accepted medical use in the US, and lesser chance or side effects of dependence compared to Schedule IV drugs. This schedule includes such drugs as cough suppressants with Codeine. Schedule V drugs are regulated but generally do not require a prescription.
Illegal to possess controlled substances without rx
Formed Drug Enforcement Agency (DEA) to enforce
DRUG NAMESGeneric Name
May be used by other manufacturers, less costly, not capitalized
Trade / Brand NameUsually shortEasy to spellCapitalizedName given by manufacturer followed with
“R”Copyright name (Tylenol, Advil, Demerol)
DRUG REFERENCESUSP / NF (FDA)United States Pharmacopeia – standard for drugs
updated every 5 years with formulas & standards for preparation & dispensation of drugs
National Formulary – drugs of established usefulness
U.S. DISPENSATORY Publication of description and composition of medicines
PDR – published annually Physicians Desk Reference – divided into color coded
sections
DRUG REFERENCES
NURSING DRUG HANDBOOKSHandbooks: Davis Drug Guide, Saunders
etc.
FACTS AND COMPARISONS listed by body system
ALSO – each HCF has it’s own ‘hospital’ formulary – cannot carry every drug; may see substitutions
PHARMACOKINETICSUse of drug by body Process that affect drug from time it enters the body to time it leaves
Divided into 4 phasesAbsorptionDistributionBiotransformationExcretion
ABSORPTIONPassage of drug from site of entry to bloodstream
What is the most common site of entry?
What factors affect absorption?
Absorption FactorsRoute of administration & conditions at
absorptive site Drug form – enteric coated; sustained
release; liquid Gastric emptying & gastric motility Timing – presence of food, other drugs – esp.
antacids
DISTRIBUTIONProgress or transportation from bloodstream to particular
site of action (receptor sites)Receptor sites or target tissue where drug chemically
bonds to cells
What factors affect distribution?Circulation, cardiac output, blood supply to site of drug
actionBinding of drugs to Plasma Protein Albumin & Tissue
bindingLevel of plasma proteins (albumin)For PO drugs, amt of drug metabolized by liver before
reaching systemic circulationBlood – Brain Barrier prevents many drugs from entering
CNS
BIOTRANSFORMATIONMetabolismDegradation or breakdown of drug for excretion
Process by which drug is detoxified or inactivated
What factors affect biotransformation?
BiotransformationFactors: Condition of liver – most drugs
detoxified by liver – need to check LFT’s“First Pass” thru liver is why oral drugs are
given in higher dosesChemicals or drugs that stimulate production
of transforming enzymes = decreased drug effect
Chemicals or drugs that decrease production of transforming enzymes = increased drug effect, cumulative effect, increased adverse reactions
EXCRETIONElimination of the drug from the body
What factors affect excretion? Kidney – condition of kidney as this is the main excretory organ
Other excretory – respiration, perspiration, defecation
BLOOD LEVELSAmount of drug in circulating fluid is often measured
Drug half life – amount of time for serum concentration to decrease by 50%
Commonly done with Antibiotics, Lanoxin, AED’s
Medication Actions and Interactions
LOCAL – affects only area drug is placed, not absorbed into blood stream
SYSTEMIC – absorbed into bloodstream
TERMSTherapeutic EffectAgonistAntagonistAdditiveSynergistic / Potentiating
Therapeutic: desired or intended effectAgonist: drug that produces a response, stimulates
a responseAntagonist: drug that blocks the action of another
drug, opposing effect sometimes desired – Narcansometimes undesired – Antibiotics & BCP’s
Additive: 2 drugs with similar actions sum of their effects
1+1=2 (alcohol + sedatives)Synergistic: 2 drugs with different actions
produce greater effects 1+1=3 (Codeine + ASA)
IncompatibilityIdiosyncraticAnaphylactic (Allergic)CumulativeAdverse Effect / Side Effect
Incompatibility: drugs that do not combine chemically with other drugs, don’t mix, compatibility charts on nursing units
Idiosyncratic: unusual or unexpected + highly individualized
Anaphylactic: Hypersensitivity; antigen/antibody reaction – can be severe, life threatening Be careful to check allergies
Cumulative: drugs that build up in the body, may be d/t increased dose, poor circulation, metabolism or excretion
Adverse Effect: undesired action – usually classified by body system
are considered adverse but can be helpful in some situations i.e. Pt has angina& HTN, Nitrates vasodilate + also lowers B
P
DRUG FORMSLiquids
Oral, parenteral, topical, instillation
SolidsTablets, caplets, capsules, powder, zydis
Liquids:Parenteral: other than GI ( IM, SC, ID, IV,
inhalation)Instillation: eyedrops, eardrops, other
examples
Solids:Powder: often mixed with liquids (diluent)Zydis: on tongue + dissolves
SemisolidsSuppositoriesOintments, Pastes
InhalersMetered dose decreases systemic effects
Transdermals
DRUG DOSAGEFactors to be considered:AgeWeightPhysical HealthPsychological Status
More FactorsEnvironmental Temp.GenderAmount of food in stomach
Dosage forms
DOSAGE CONSIDERATIONSTherapeutic doseMinimal doseLoading doseMaximal doseToxic doseLethal dose
MEDICATION ORDERSWho can write a prescription?
Written ordersVerbal ordersStanding ordersStat orders
PARTS OF A PRESCRIPTIONPt NameDate, TimeName of DrugDose of DrugTime / FrequencyMethod / RouteHC Provider SignatureDOBSpecial Instructions