Transcript Unit 5 - Workforce Solutions

Unit 5
Basic Pharmacology
and Contrast Media
Chapters 20 & 21
Pharmacology
Chapter 20
Introduction
• Pharmacology
– Study of drug actions on & drug interactions
within living organisms
• Drugs
– Chemical substances that are not required for
normal sustenance & that produce a biological
effect in an organism
– All drugs, if misused, are poisons
Scope of Practice
• Radiographer’s ability to administer drugs &
perform venipuncture vary from state to
state
• Expected to know safe dosage, safe route of
administration, limitations of drug, side
effects, potential adverse & toxic reactions,
indications & contraindications for its use
Scope of Practice
• If drug administration errors occur because
of lack of knowledge, the person who
administers the drug is legally liable
• Errors associated with drug administration
are the most common legal problem for RTs
• Drug administration must be charted!
– Name and dose of drug
– Route of administration (& site)
– Date and time
Drug Standards
• Food & Drug Administration (FDA)
– Enforces strict standards for control of
drug safety
– New drugs must be tested on animals
and/or humans
– Properties regulated
• Purity, bioavailability, potency, efficacy,
safety & toxicity
Drug Nomenclature
• A classified system of names
– By name
– By action
– By method of legal purchase
• Drugs have 3 different names
– Chemical name
– Generic name
– Trade name
Classification by Name
• Chemical name identifies the chemical structure of
the drug
– Ex: 7-chloro-1,3dihydro-1-methyl-5-phenyl-2H-1,4benzodiazepin-1-one
• Generic name (aka “nonproprietary name) is
simpler, easier to pronounce, not capitalized
– Ex: diazepam
• Brand name is specific to the company
(trademark); always capitalized
– Valium
Classification by Action
• Drugs with similar chemical actions are
grouped into categories called drug
families
– Ex: analgesics, antihypertensives,
antiinflammatories
Legal Classification
• Prescription vs. Nonprescription
• Prescription drugs require an order by a
physician.
– Dispensed only by a pharmacist
• Nonprescription drugs = over-the-counter
(OTC) drugs
– Also dietary supplements
Drug Control
• Over-the-counter drugs (OTC)
– Drugs that are considered safe for selfadministration
– May be prescribed drugs sold in lesser potency
– Must be deemed safe by FDA
• Dietary supplements not controlled by the FDA!
– Important to note OTC drugs in patient history
• Some interact with prescription drugs!
Pharmacology:
Reliable Sources of Information
• Reference books (examples)
– Physicians’ Desk Reference (PDR)
– United State Pharmacopeia
– Updated yearly
Dose Forms
• The manner in which the drug is
prepared or transported into the human
body
• A single drug may have several dose
forms
• Determines speed or onset of the drug’s
therapeutic effect.
– Ex: tablets, capsules, suppositories
Dose Forms - Tablets
•
•
•
•
Most common oral dose form
Compressed granules
Easiest to administer
Single dose units
– May be scored
– May be coated
• to delay absorption or
• protect mucosa
Dose Forms - Capsule
• Powder or liquid drug contained in a
gelatin shell.
• Can be time released
Dose Forms - Inhalant
• Can be used for local or systemic
effects
– Local – ex: asthma
– Systemic – ex: general anesthesia
Dose Forms – Suppository
• Used for insertion into a body orifice
– Ex: rectum, vagina
• May have local or systemic effect
Dose Forms – Solution
• One or more drugs are dissolved in a
liquid
• Usually rapidly absorbed
• May be administered orally or
parenterally (injected)
Dose Forms – Suspension
• One or more drugs (small particles) are
suspended in a liquid
• Administered only orally
• Must be shaken well
Dose Forms – Transdermal patch
• Permits drug application on the skin
– Absorbed into the bloodstream
Drug Administration –
The 5 Rights
1. The Right Drug
–
Check the label 3 times!
2. The Right Amount
3. The Right Patient
–
Check the armband!
4. The Right Time
5. The Right Route
Drug Administration –
The 5 Rights
• Read the label 3 times
– Before drawing up, while drawing up, before
administering to patient
• Check expiration date
• Discard cloudy solutions
• Identify patient; explain what medication is
being administered
• Ask patient drug history
• Do not leave unattended a patient who may be
having a drug reaction
Routes of Drug Administration
• Oral – taken by mouth & swallowed into the
stomach (PO)
– Most efficient & most cost-effective method
– Used if the drug will not be destroyed by secretions
in the GI tract
– Used when slower absorption & longer duration of
drug activity are desired
– Disintegrates & dissolves in stomach, then travels
to small intestine where most absorption takes place
– Patient must be conscious
Routes of Drug Administration
• Reasons for not giving drug orally
–
–
–
–
–
–
–
Unpleasant taste
May cause nausea & vomiting
May be destroyed by digestive juices
May be danger of aspiration
Patient may be uncooperative
Rapid absorption may be desired
May irritate gastric mucosa
• May be given in enteric-coated form
• Patients informed not to chew tablet before swallowing
Routes of Drug Administration
• Sublingual – drug is placed under the tongue;
allowed to dissolve
– Ex. Nitroglycerin tablets
• Topical – application directly on the skin;
absorbs through the bloodstream
– Ex. Transdermal patch
Routes of Drug Administration
•
•
Administered by injection
Requires aseptic technique and
standard precautions
•
•
3 most common routes:
Intramuscular (IM)
1. Subcutaneous (SC)
2. Intravenous (IV)
Routes of Drug Administration
• Subcutaneous (SC) – into the subcutaneous
tissues
• Intramuscular (IM) – into the muscle
• Intravenous (IV) – into the vein
• Intrathecal – into the spinal subarachnoid
space
• Epidural – into the spinal on or outside the
dura mater surrounding the spinal column
Routes of Drug Administration
• Intra-articular – within the joint
• Intra-arterial – into an artery
• Pulmonary – into the lungs
• Intradermal – beneath the skin surface
– Ex: PPD test for TB
Routes of Drug Administration
• Subcutaneous
– Administered below the epidermis
– Absorption is through the capillaries at a
fairly rapid rate
– Dosage should be no more than 1-2 mL
Routes of Drug Administration
• Intramuscular
– Absorption is variable depending on the drug & the
muscle into which the drug is injected
– Deltoid, gluteal, & vastus lateralis muscles are most
frequently used
– Deltoid – blood flow is more rapid than the gluteal
muscles
– Gluteal – larger amount of drug can be administered
– Solutions absorb most rapidly
– Suspension & oil-based emulsion absorb more slowly
Routes of Drug Administration
• Intravenous
– Most rapid systemic response – no barrier
to absorption
– Method selected if rapid effect is desired
or if drug cannot be injected into body
tissues without damaging them
– One of the most hazardous routes –
reaction is immediate
Routes of Drug Administration
• Intrathecal, epidural, intra-articular, &
intra-arterial
– Used to achieve high local concentration
of a drug for pain relief, treatment of
neoplasms, to inject contrast media for
diagnosis, or to administer anti-infective
drugs
– Intrathecal – bypass blood-brain barrier
Routes of Drug Administration
• Pulmonary
– Used to administer drugs in the forms
aerosols or gases
– Used to assist with normal oxygen-carbon
dioxide exchange in the lungs
– Used to treat patients in respiratory
distress
Routes of Drug Administration
• Topical
– Used for local treatment of skin ailments
as well as systemic treatment
– When unbroken, skin is slow to absorb
drugs into systemic circulation
• Rate of absorption is accelerated if there is an
open lesion or if the drug is applied to mucous
membranes or to the area behind the ear
(postauricular area)
Routes of Drug Administration
– Administered to the eye, nose, throat,
respiratory mucosa, vagina, or sometimes
rectum
– Transdermal
• Drugs applied to the skin for intended
systemic effect
• Absorbed slowly; constant blood level of the
drug is achieved
Equipment for Drug
Administration
• Needles
–
–
–
–
Range in length from 3/8 – 2 inches for average use
Longer needles used for special procedures
Made of stainless steel
Parts
•
•
•
•
Hub – part that attaches to the syringe
Shaft – elongated part of the needle
Lumen – hollow tube that runs length of shaft
Bevel – sharp, angulated tip of the needle
Equipment for Drug
Administration
• Size of needle
– Smaller the lumen, the larger the gauge of
the needle
• 18 gauge – lumen larger than 25 gauge
– Viscosity of fluid determines the gauge
selected
– Area for injection & condition of patient
determines the length of the needle chosen
Equipment for Drug
Administration
Tip
Barrel
Plunger
• Syringes
– Vary in size from 1 – 60 ml
– Parts of syringe
• Tip
– end of the syringe to which the needle is fastened
• Barrel – body of the syringe
• Plunger – inner part that fits into barrel
– Calibrated in ounces & ml (cc’s)
Equipment for Drug
Administration
• Needles & syringes
–
–
–
–
–
–
Packaged to maintain sterility
Some have safety locks to prevent needle-stick injuries
Disposable – should not be reused
Should be disposed of in sharps container
Needles used on a patient should never be recapped
Do not place used needles & syringes back onto tray to
be disposed of later
• Could cause potential needle-stick injury
Equipment for Drug
Administration
• Angiocath is the safest device to use for
venipuncture
• After insertion, needle is extracted
through a sheath
• Less chance of accidental injury
Packaging of Parenteral
Medications
• Packaged to maintain sterility
• Small amounts
– Ampules, vials
• Larger amounts
– Glass or plastic container
Packaging of Parenteral
Medications
• Vial
– Glass container with rubber stopper
circled by a metal band
– Band holds rubber stopper in place
– Generally available in 5-, 10-, 20-,
30-, 50-mL sizes
– On label
• Name of med, dosage per mL, route by
which it may be administered
Packaging of Parenteral
Medications
• Cleanse top of rubber stopper with alcohol wipe
• Draw air equivalent to the amount of fluid to be
withdrawn from vial into syringe
• Insert needle into vial & inject air in the syringe
• Fluid in vial will replace air in syringe rather
quickly
• Plunger of syringe can be drawn back until exact
amount of drug needed is obtained
Packaging of Parenteral
Medications
• Ampule
– Made up of glass & contains a
single dose of a drug
– Indented area at the neck can be
opened by snapping it off with a
sterile gauze pad
– Label contains same info as vial
– Single use only
Packaging of Fluids &
Medications for Intravenous Use
• Large volume (50-1000 mL) packaged in either
heavy plastic or glass containers
– Plastic bags
• Collapses under atmospheric pressure as fluid leaves
• 2 ports – one for IV tubing, one to use if other drugs are
to be added to the infusion
– Glass bottles
• Do not collapse
• Must be constructed with an air vent so that
air can replace fluid as it infuses into the vein
• Rubber stopper like vial
Abbreviations
• Review common abbreviations
in the text!
Methods of Drug Administration
• Parenteral Drug Administration
– All equipment that penetrates skin must be
sterile
– Patient must be correctly identified
– Explain procedure to patient; identify
medication to be administered
– Skin at injection site is cleansed with an
antiseptic solution to be as free of
microorganisms as possible
Methods of Drug Administration
• All persons administering parenteral drugs
must wear gloves
• Must be a physician’s order for medication
• Five rights must be followed
• Patient must be observed for 1 hour after
drug administration for adverse or allergic
reactions
• Patient who has had a sedative, tranquilizing,
or hypnotic drug may not drive him- or
herself home
Intradermal Administration
• Also called intracutenous injections
• Used for testing for sensitivity to a drug or
antigen and local anesthesia administration
–
–
–
–
Tuberculin syringe used
Skin cleansed with alcohol
Insert needle bevel side up at a 5-10° angle
Inject drug – small raised area, or wheal, should
be seen
Subcutaneous Administration
• Medications are injected into tissues
beneath the dermis at a 45° angle
• Tuberculin syringe may be used if
amount is less than 1 mL
• Given in the outer aspect of the upper
arms, abdomen, scapulas, or the
anterior thigh
Intramuscular Administration
• Chosen when prompt absorption of
drugs is desired because there is a rich
blood supply to muscles
• Chosen when medication given SC
would be irritating to the tissues &
when a larger amount of a drug is
needed
– Amount of medication given = 1-5 mL
Intramuscular Administration
• Sites commonly used
– Dorsal gluteal, ventrogluteal, rectus
femoris, deltoid
– Dorsal gluteal
• Have patient in prone position with entire
gluteal muscle exposed
• Use iliac crest as superior boundary
• Gluteal fold – inferior boundary
• Divider buttock into 4 quadrants
– Injection given into upper outer quadrant
Intramuscular Administration
• After cleansing site, place non-dominant
hand on muscle to be injected to support
patient
• Quickly insert the needle into the muscle at a
90° angle
• Aspirate to ensure no blood return
– Blood return would indicate entrance into blood
vessel
• If no blood, inject fluid into muscle &
quickly withdraw needle
Peripheral IV Drug
Administration
• Immediate effect
• One of the most hazardous routes
– Drug is injected directly into circulatory
system; reaction instantaneous
• Must not leave a patient receiving an
IV drug or contrast agent alone
Peripheral IV Drug
Administration
• Piggyback
– Small IV infusion which is attached to an adjoining
or already existing line
• Bolus
– Designated amount of a drug that is administered at
one time, over a period of several minutes
• (Drip) Infusion
– Larger amount of a drug, fluid, or fluid containing
a drug or electrolytes that is administered over a
longer period of time ranging from hours to days
Peripheral IV Drug
Administration
• Extravasation (infiltration) – seepage of drug
into the tissues surrounding the vessel.
–
–
–
–
Immediately remove needle
Apply pressure
Apply warm moist heat to relieve discomfort
If drug is corrosive, apply cold compress instead
• Physician/pharmacy should be notified
The Medication Order &
Documentation
• No health care worker may take it on
him- or herself to prescribe or
administer drugs that are not ordered
by a person licensed to do so
• 3 ways in which orders may be given
by a doctor
– Written, verbal, standing
The Medication Order &
Documentation
• Order must be dated, written, & signed by
physician
• Info needed on an order
– Patient’s full name, date, & time order is written
– Date & time(s) that the drug is to be
administered
– Generic or trade name of drug
– Dosage form & route of administration
– Physician’s signature
The Medication Order &
Documentation
• Stat orders – immediately
• prn (pro re nata)
– As the occasion requires
– Standing order for pain medication
• Single order – written for a medication
to be given only once at a designated
time
Medication Errors
• It is your legal & ethical obligation to
be knowledgeable about any drug you
feel competent to administer
• If you administer a drug incorrectly or
misinterpret an order from a physician,
you are legally liable & have violated
your code of professional ethics
Medication Errors
• Medication error or adverse reaction
– Notify physician
– Note in patient’s chart
– Fill out incident report
UNIT 5
Contrast Media and Introduction
to Radiopharmaceuticals
Chapter 21
Contrast Media
• Purpose: To visualize anatomic detail in
areas which lack inherent subject contrast; to
increase the differential absorption of
radiation in adjacent anatomic structures.
• Contrast Media – agents instilled into body
orifices or injected into various anatomic
regions to enhance subject contrast
– Classified as negative or positive
Contrast Media
• Positive contrast - high atomic number
– Radiopaque - Increases x-ray absorption in
the structure- Appears white on the image
• Negative contrast - low atomic number
– Radiolucent – Decreases x-ray absorption
in the structure - Appears dark on the
image
– Often used in combination with positive
contrast
Negative Contrast Media
• Composed of low atomic number elements
• Administered as gas (air) or gas-producing
tablets, crystals (carbonation)
• Rarely used alone
• Used in combination with positive contrast
agents
• Ex: Laryngopharyngography, air contrast
barium enema
Positive Contrast Media
• Composed of high atomic number elements
• Ex: Barium Sulfate (used primarily in GI tract
imaging)
• Ex: Water soluble Iodine (used in vascular,
urographic and arthrographic studies.
• Some complications/adverse reactions possible
Barium Sulfate
•
•
•
•
•
•
•
Barium has atomic #56
Radiopaque
Used to examine GI tract
BaSO4
Not water soluble
Suspension
Flocculation – clumping; comes out of
suspension
• Administered orally or rectally
• Mixed with cold (cool) water to reduce
irritation, spasm and cramping
• Often used with air
Barium Sulfate
• Contraindication:
suspect perforation of GI
tract; water soluble
contrast is used instead
• Complications: rupture;
peritonitis; constipation;
obstruction;
Water Soluble Iodinated
(Positive) Contrast Media
•
•
•
•
Iodine has atomic # 53
Radiopaque
Water soluble
Most frequently used intravascular contrast agents
contain iodine
• Administered by injection (intravenous &
intraarterial), orally, rectally
• Adverse reactions possible – need allergic history
• Ionic vs. Nonionic
– Ionic results in more adverse reactions as compared with
nonionic
Water Soluble Iodinated
(Positive) Contrast Media
• Ex: Anaphylactoid effect (urticaria, wheezing,
edema in throat/lungs bronchospasm, nausea,
vomiting)
• Increased risk for patients with renal
disease/diabetes
• Some drug interactions can cause contrast reactions
– Ex. Beta blockers; calcium-channel blockers; Metformin
(Glucophage) should be discontinued 48 hours prior to
exam
Water Soluble Iodinated
(Positive) Contrast Media
• Never leave patient unattended
• Informed consent required
• Contrast should be administered at body
temperature
• Excreted through kidneys - Instruct patient to
increase fluid intake after procedure
Oil-based Iodinated
(Positive) Contrast Media
• Insoluble in water
• Viscous
• Decompose when exposed to light,
heat, air
• Do not use plastic syringes
• Disadvantage: persist in the body
• Application: hysterosalpingography,
bronchography, sialography,
lymphography
Reactions to Contrast Agents
• Classifications of adverse reactions
– Mild
•
•
•
•
Complaints of itching of nose & eyes
Anxiety
Cough
Hives or rash
Reactions to Contrast Agents
• Intermediate
– Coughing that results from laryngospasm or
angioedema of the upper respiratory tract leading
to a feeling of tickling in the throat
– Dyspnea & wheezing resulting from edema
– Initial symptoms of shock
• Anxiety, rapid pulse, rapid respirations, hypotension
– Chest pain
Reactions to Contrast Agents
• Major
– Shock
– Seizures
– Cardiac arrest
• Vasovagal reaction
– Patient experience high anxiety about procedure
& its result
– Symptoms include pallor, cold sweats, syncope,
tachycardia or bradycardia, hypotension
Patient Assessment & Care
• Examples of history questions
–
–
–
–
–
Liver disease
Kidney disease
Hypersensitivity reactions (allergies)
Heart disease
Previous reactions
Sponsored by:
•
This workforce solution was funded by a grant awarded under the President’s Community-Based Job
Training Grants as implemented by the U.S. Department of Labor’s Employment and Training
Administration. The solution was created by the grantee and does not necessarily reflect the official
position of the U.S. Department of Labor. The Department of Labor makes no guarantees,
warranties, or assurances of any kind, express or implied, with respect to such information, including
any information on linked sites and including, but not limited to, accuracy of the information or it’s
completeness, timeliness, usefulness, adequacy, continued availability, or ownership. This solution
is copyrighted by the institution that created it. Internal use by an organization and/or personal use
by an individual for non-commercial purposes is permissible. All other uses require the prior
authorization of the copyright owner.