week 1 Flashcards
assessment
OBEJECTIVE DATA AND SUBJECTIVE DATA
NURSING DIAGNOSIS
ANALYZES THE OBJECTIVE AND SUBJECTIVE DATA ABOUT THE PATIENT AND THE DRUG AND FORMULATES NURING DIAGNOSIS
PLANNING
GOALS, OUTCOME TIME FRAMES, PATIENT ORIENTATED
IMPLEMENTATION
THE NURSE INTERVENES
EVALUATION
MONITORING WHETHER PATIENT GOALS AND OUTCOME CRITERIA RELATED TOT HE NURSING DIAGNOSES ARE MET.
MED ORDER
- PATEINTS FULL NAME
- DATE AND TIME WRITTEN
- GENERIC AND TRADE NAME OF DRUG
- DOSAGE OF THE DRUG
- ROUTE OF ADMIN
- SIGNATURE OF THE PRESCRIBER
RX SYMBOL
MEANS “TAKE THOU”
NANDA
MAJOR CONTRIBUTOR TO THE DEVELOPMENT OF NURSINF KNOWLEDGE AND IS CONSIDERED THE LEADING AUTHORITY IN THE DEVELOPMENT AND CLASSIFICATION OF NURSING DIAGNOSES
THE NURSE MUST CHECK THE MEDS
3 TIMES PRIOR TO ADMIN
The scope of practice model set out in the RHPA
contains two elements:
- a scope of practice statement; and
2. controlled acts authorized to the profession
The Traditional Five Rights of Medication Administration
Right drug Right dose Right time Right route Right patient
Additional Rights of Medication Administration
Right reason Right documentation Right evaluation (assessment) Right patient education Right to refuse
Drug
Any chemical that affects the physiological process of living organisms
Drug is a substance used to cure, to treat, or to prevent a disease or condition
Pharmaceutics
The science of dosage form design (eg: tablets, capsules, injections, creams, patches, suppositories etc.)
Studies how drug forms influence the Pharmacokinetics and Pharmacodynamics
Pharmacokinetics
(what the body does to a drug once it enters the system…..follow four phases)
Pharmacodynamics
what the drug does to the body once it enters the system…..drug response)
Four phases - Pharmacokinetics
Concentration of drug at the site of its action is influenced by 4 primary factors
- Absorbed into body fluids
- Distributed to the sites of action or storage
- Biotransformed or metabolized to breakdown or active metabolites
- Excreted from the body by various routes
Parent drug
is the actual drug before it is metabolized. In its pure form.
Metabolite
is the break down or the by-product of the parent drug which can be either active or inactive.
Pharmacokinetics :Absorption
Begins from the time a drug leaves its site of administration to the point where is absorbed into the system.
Variables that affect absorption
- Nature of the absorbing surface area (cell membrane)
• Transport faster through single layer of cells (intestinal epithelium) then through many layers of cell (skin)
• The greater the absorption surface the faster the effects - Blood flow to the site of administration
• Rich blood supply (sublingual route) enhances absorption - Solubility of drug
• Liquid drugs are more rapidly absorbed
• Administered with food will slow absorption
• Administered with water will dilute the drug and will absorbed faster - ph
• Acidic drug (aspirin) can easily cross over membranes into circulation through gastric membranes
• Base drugs are easily absorbed through the small intestine - Drug concentration
• High concentration tend to be more rapidly absorbed
• Loading doses—large temporary dose given to obtain a rapid therapeutic response—then followed by smaller daily doses Maintenance dose—to maintain therapeutics response - Dosage form (eg enteric coated)
• Prevent decomposition by gastric secretions
• Prevent dilution of the drug before it reaches the small intestine
• Prevent nausea and vomiting
• Provide delayed action of the drug - Routes of drug administration
• Affects onset of drug action
• Affects therapeutic response
• Enteral (administered along any portion of the GI tract)
• Parenteral (SC. IM, IV, intrathecally (spinal anesthesia), epidural (epidural spaces of the spinal column), intraarticular (between joints), intraossesous (in the bone)
• Pulmonary route
• Topical route - Disease Process
• Drugs absorbed by the gut will be affected in those patients with bowel disease, resection of the bowel, Crohn’s disease, Ulcerative Colitis, cancer etc.
Person in shock—
poor peripheral circulation –poor absorption of intramuscular injection
IV administration into the blood stream—
speed drug effects slow injection important—poor circulation—decreased blood flow may cause decrease to the rate of transportation of drug to target tissues—alter drug effects
Cells contain fatty acid layer—alimentary system—Gi tract—esophagus, stomach, duodenum, jejunum/ileum, colon, gall bladder—system that prepares food for excretion.
Drugs that are not soluble in water or in lipids cannot be absorbed
Loading doses—
large temporary dose given to obtain a rapid therapeutic response—then followed by smaller daily doses maintenance dose—to maintain therapeutics response
Dosage form –
example combine a resin with an active form of drugs causing slow release of drug or resistance to digestive action (enteric coated).
Liquids, elixirs, syrups
are the Fastest Oral Preparations
and Enteric-coated tablets being the Slowest
First-Pass Effect
• The metabolism of a drug and its passage from the liver into the circulation
– Orally administered drugs pass to the venous portal system than the liver before entering the general circulation.
– A drug given via the oral route may be extensively metabolized by the liver before reaching the systemic circulation (high first-pass effect)
– The same drug—given IV—bypasses the liver, preventing the first-pass effect from taking place, and more drug reaches the circulation
Routes that bypass the liver:
Sublingual Transdermal Buccal Vaginal Rectal* Intramuscular Intravenous Subcutaneous Intranasal Inhalation *Rectal route undergoes a higher degree of first-pass effects than the other routes listed.
Pharmacokinetics: Distribution
- Transport of a drug in body fluid from the bloodstream to various tissues and site of action (ie receptor site)
- Volume of distribution is used to describe areas where the drugs are distributed. ie a drug which primarily works on the lungs (ie. Ventolin) is said to have a high volume of distribution to lung tissue
Distribution
- Plasma Protein binding
• Attaches to plasma protein (e.g. albumin in blood… acts as a carrier)—forms drug protein complex.
• Albumin is the human body transporter of essential fatty acids from adipose tissue (fat) to muscle tissue
• Protein bound drugs attach themselves to a protein which makes them too large to pass through the walls of the blood capillary into the tissue.
• A drug can be distributed to tissue only if it is not bound to protein – free drug - Tissue binding
• Lipid soluble—these drugs are difficult to eliminate, stored in the fatty tissue and therefore administration of drugs too soon may cause cumulative effect leading to toxicity
• Whereas water soluble drugs are easily excreted - Blood brain barriers
• Some drugs are blocked from entering these sites - Placental barrier
• Therapeutic response in mother may cross to developing fetus e.g.. Steroid, narcotics, anesthetic, antibiotics - Areas of rapid distribution:
• Heart, liver, kidneys, brain (high blood supply areas) - Areas of slow distribution:
Muscle, skin, fat (low blood supply areas)
Pharmacokinetics: Metabolism or Biotransformation
The biologic transformation of a drug into an inactive metabolite (for excretion), a more soluble compound (easier to be absorbed), or a more potent metabolite (can also elicit drug effects)
• Liver (main organ responsible for biotransformation)
• Kidneys
• Lungs
• Plasma
• Intestinal mucosa
Majority metabolized in the liver by hepatic microsomal enzyme system
—cytochrome P-450system –affect lipid soluble nonionized drugs
In this system drugs undergo two types of chemical reactions—chemical reaction of oxidation hydrolysis or reduction to increase the water solubility of molecule
2nd—joining of drug with another body substance like glucuronide, glycine, methyl or alkyl –molecule becomes more water soluble and therefore may be excreted by kidney.
Cytochrome P-450 Enzyme
This enzyme is very important as it controls a variety of chemical reactions that help the metabolism process
Also helps to metabolize lipid-soluble drugs to a form which aids in the elimination process thereby making it easier on the kidneys
Factors that decrease metabolism
• Cardiovascular dysfunction • Renal insufficiency • Starvation (electrolyte imbalance) • Obstructive jaundice (unable to metabolize drugs) •
Delayed drug metabolism results in:
- Accumulation of drugs
- Prolonged action of the drugs
- Leading to toxicity in the body
Pharmacokinetics: Elimination/Excretion
The process by which drugs and its active or inactive metabolites are eliminated from the body.
Primary routes
-Renal tubules into urine
-GI tract to feces (known as “biliary excretion”)
Other routes
- Evaporation through skin
- Exhalation from lungs
- Secretion into saliva
- Breast milk
Most drugs are extensively metabolized in the liver that by the time it reaches the kidneys only a small fraction of the drug gets excreted.
Some drugs which are minimally metabolized in the liver may reach the kidney in its original state.
ie Vitamin C
Mechanism of Drug Action
How does the drug act at the biochemical or cellular level to produce its therapeutic effects
(ie. What the drug is used for and how the drug works)
General Properties of DrugsHow They Work
- Modify existing functions
• Replacing, interrupting or potentiating the physiologic process in specialized tissues
• ie Digoxin works on the SA node thereby preventing or correcting any arrhythmia - Exerts multiple actions rather than a single effect
• May produce undesirable response because of their potential to modify more than one function of the body
• ie Corticosteriods (Prednisone) affects multi- organs during treatment - Physicochemical interaction between the drug and functionally important cells in the body
• Drug interacts by combining with components of tissues (receptors)
• ie Calcium used for muscle contractions can concentrate itself on heart tissue
Half Life = t1/2
A measurement of time required for elimination
The amount of time required for 50% of the original amount of the drug to be eliminated from the body
Most drugs have 5.5 half lives before the drug is totally eliminated from the body
Half-Life = t1/2
- 100mg of a drug with a half life is 12hr
- Time Half-Life Drug Remaining
- 0 – 100mg (100%)
- 12 1 50mg (50%)
- 24 2 25mg (25%)
- 36 3 12.5mg (12.5%)
- 48 4 6.25mg (6.25%)
- 60 5 3.12mg (3.12%)
half life cont.
Drugs with a short half life require more frequent dosing, whereas drugs with a long half life require less dosing schedules
The half life information is important to determine dosing….how often to give a medication in order to maintain a constant blood level. ie with seizure medications it will prevent seizures if the patient is well controlled
Also important in toxicology as it determines how long to monitor a patient for symptoms
Onset—
the time between drug administration and the first sign of its effect (time it takes for a drug to elicit a therapeutic response
Peak plasma level—
highest plasma concentration attained from a dose (time it takes for a drug to reach is maximum therapeutic response)
Duration of action—
the period from the onset of the drug action to the time when a response is no longer seen (length of time that the drugs blood concentration is sufficient to elicit a therapeutic effect)
Drug action–The action of the drug at the receptor site
The action of the drug at the receptor site
Drug effect–
The physiologic reaction of the body to the drug. (the term onset, peak and duration are used to describe the drug effects)
Loading dose-
-large temporary dose given to obtain a rapid therapeutic response, then followed by smaller daily doses
Maintenance dose–
to maintain therapeutics response
Agonist—
drugs capable of binding with receptors and causing a cellular response (therapeutic action)
Antagonist—
drugs that inhibit or block the action of agonists—also called blockers
Potency—
drug screen at a certain concentration or dose
Efficacy—a
ability of a drug to produce a more intense response as its concentration is increased
Receptor Sites
Drugs act by forming a chemical bond with specific receptor sites, similar to a key and lock
The better the fit the better the response
Pharmacodynamics: Mechanism of Action
- Once the drug is at the site of action (receptor site), it can modify the rate (increase or decrease) at which the cells or tissues function
- A drug cannot make a cell or tissue perform a function it was not designed to perform
- There are 3 ways which drugs produce therapeutic effects
Pharmacodynamics: Mechanisms of Action
- Receptor interaction
- Once the drug binds at the receptor site it interacts and produces a response, may be positive or negative depending on the “fit” (key lock)
- Therefore, a drug-receptor interaction joins the drug to its receptor (target cell) and sparks a response
- The degree to which a drug attacks and binds with a receptor is called its “affinity”
- A drug with the strongest and best “fit” (like a puzzle piece) to the receptor will elicit the greatest response
- Enzyme interaction
• For a drug to alter a physiological response it must inhibit the action of that enzyme
• The drug “fools” the enzyme into binding to it instead of the target cell
• This protects the target cell from the actions of that enzyme
• Interaction between drug and cell enzymes Enzymes are biological catalyst that control all biochemical reactions of the cell - Nonspecific interactions
• Interfere with or chemically alters the cellular process
• This produces defective cells which will eventually die off
• Some cancer drugs and antiviral have the ability to do this
• They penetrate or accumulate in cell membrane which interferes with the cell function and the metabolic processes
Empiric therapy-
when treatment is started before a diagnosis is confirmed (example:antibiotics). The most common reason is that investigations are sometimes needed in order to confirm a diagnosis, which take time, and a delay in treatment can harm the patient
Monitoring
The effectiveness of drug therapy must be evaluated
One must be familiar with the drug’s:
Intended therapeutic action (beneficial)
Unintended and potential side effects (predictable, adverse reactions)
Contraindication
Any characteristic of the patient, especially a
disease state, that makes the use of a
given medication dangerous for the patient
It is important to assess for contraindications!
eg. liver failure, renal failure
Adverse Drug Reaction (ADR)
• Any reaction to a drug that is unexpected and undesirable and occurs at therapeutic drug dosages
– Caused by processes within a patient’s body
– Has four general categories:
• Pharmacological reaction
• Hypersensitivity (allergic) reaction
• Idiosyncratic reaction
• Drug interaction
Tolerance—
decreased physiological response to drug
Therapeutic index (therapeutic window) -
the measurement of the relative safety of a drug. Ratio between the therapeutic effect and a toxic effect.
Interactions—
the effects of the drug are modified by the administration of another medication— increasing (synergistic effect) or decreasing the effect of drug (milk and tetracycline)
Side effects/adverse drug effects (drug/drug or drug/food interactions)
Dependency—
habituation and addiction both physical and psycholoigc
Drug withdrawal
Allergic reactions—
type 1 anaphylactic reaction—contraction of smooth muscles may begin with irritability, extreme weakness, nausea, vx dyspnea, cyanosis, convulsions and cardiac arrest
Additive effect -
drugs with similar action are taken for double effect ie. Heparin + Coumadin
Synergistic effect -
combined effect of two drugs is greater then the effect of each drug alone
Tylenol + Codeine
Antagonistic effect -
one drug interferes with the action of the another – blocks the effects
Incompatibility -
when mixed together the drugs are not compatible and an adverse reaction can develop
Pharmacologic reactions –
incompatibility of drugs
Idiosyncratic reactions—
unusual or abnormal response for a specific patient, ie. genetic inability to metabolize drug
Hypersensitivity reactions-
allergic reaction; hives or urticaria, anaphylactic reaction
Iatrogenic Responses
Unintentional adverse effects that are treatment induced or medication administered with potential harm to a patient that is caused by health care staff members (not following policies or standards or care)
Teratogenic -
malformation of fetal organs while in uterus due to exposure to drugs or chemicals
Mutagenic -
a chemical or drug that can induce or increase the frequency of mutation in an organism ie. Antiviral agents
Carcinogenic -
drug induces abnormal or normal living cell to mutate and become cancerous
Toxicology
The study of poisons and unwanted responses to therapeutic agents
Utilization of the Poison Centre located at The Hospital for Sick Children is staffed by Certified Specialist in Poison Information (CSPI)
- Orphan Drug Act
aids in the development of drugs for the treatment of “rare” diseases
- Medication Misadventure
3 any undesirable medication related event ranging from mild discomfort to death. Usually as a result of Iatrogenic Hazard.
- Toxicology
4 study of poisons. Deals with effects of drugs and chemicals, their detection and treatment to counteract their poisonous or toxic effects on the body.
- Dissolution
5 how a solid drug disintegrates or breaks down in the GI tract and how it gets absorbed into the circulation.
- Cytochrone P-450
- 6 general term for a wide variety of tissue enzymes (especially in the liver) that plays a significant role in drug metabolism.
- First Pass Effect
the initial metabolism in the liver of a drug that is absorbed from the GI tract before it reaches systemic circulation through the bloodstream.
- Efficacy
. 8 therapeutic effectiveness of a drug
- Therapeutic Index
the difference between the minimum therapeutic and toxic concentrations of a drug. If the index (or window) is narrow, the range between the therapeutic and toxic drug concentration is small.
- Idiosyncratic Reaction
- 10 an abnormal or unexpected susceptibility to a medication that is specific to that pt. Abnormal responses to standard doses or a drug.
- Adverse Drug Event
11 injury that is caused by a medication or failure to administer a medication. May or may not cause patient harm. (ie forgetting to give a pt his puffers for asthma and in turn the pt has an asthma attack)
- Steady State
STEADY STATE the physiological state in which the amount of drug removed via elimination is equal to the amount of drug absorbed with each dose.
- Canadian Narcotic Control Act
enacted in the mid 1960’s. Concerns with sale,
manufacturing, production and distribution of narcotics
- Placebo
14 an inactive (inert) substance (saline, sugar, water). Used in investigational drug studies or for those patients who cannot be given the medication they are requesting or for those in the judgment of the health care provider do not need the medication.
- Agonist
agonist a drug that binds to and stimulates the activity of one or more receptors in the body. This results in a stimulatory effect.
- Bioavailability
16 measurement of how much drug could be absorbed
- Affinity
affinity the degree to which a drug attacks and binds with a receptor
- Expedited Drug Approval
18 the drug approval process is shortened if the drug shows
promising benefits in Phase I and Phase II. Given only to qualified pt in urgent situations.
- Contraindications
19 any drugs, diseases or patient characteristics that should not be given or combined due to the possibility of and undesirable effect
- Iatrogenic Hazard
20 potential harm to a patient that is caused by health care staff members (not following policies or standards or care)
- Synergistic Effect
. 21 a drug interaction that results from combined drug effects that are greater than those that could have been achieved if the drugs were given alone. Enhanced effects.
- Chemical Name
the name that describes the drug’s chemical composition and molecular structure. The make up of the drug.
- Parent Drug
23 the chemical form of a drug given to the body before it is metabolized into active or inactive metabolites.
- Generic Name
the name given to a drug by the United States Adopted Names (USAN) council. Also called “non proprietary name”. This name is much shorter and simpler than the chemical name.
- Federal Food and Drug Act
first Federal law that attempted to protect the public
from dangerous products or mislabeled products.
- Antagonistic Effect
27 a drug interaction that results with combined drug effects are less than those that could be achieved if either drug were given alone.
- Side Effect
28 any undesirable effect of a medication that is expected or anticipated to occur in a predictable percentage of patients who receive a given medication. Can range from mild to severe.
- Pharmacognosy
29 the study of drugs that are obtained from natural plant and animal sources.
- Pharmacokinetics
. 30 the study of drug distribution rates between various body compartments after the drug has entered the body. (ie phases of absorption, distribution, metabolism, and excretion of a drug)
- Therapeutic effect
. 32 ratio between a drug’s therapeutic index and toxic effect
- Cumulative effect
. 33 drugs that build up in the system as a result of poor excretion
