Transcript PowerPoint_Chapter4x

Chapter 4
Immunologic Drugs and
Vaccines
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Chapter 4
Topics
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Physiology of Acquired Immunity
Immunization
Interferon Therapy
Immunosuppression
Immunoglobulins, Antitoxins, and Antivenoms
Herbal and Alternative Therapies
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Physiology of Acquired Immunity
Acquired Immune
Response
• Body’s built-in defense
mechanism against
pathogens
• Systemic response
 Pathogens are carried
to the lymph nodes
 Lymphocytes then
detect and destroy
pathogens
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Physiology of Acquired Immunity
Acquired Immunity
• Helper T cells
 Detect specific antigens (molecules on foreign
pathogens)
 Stimulate killer T cells and B cells to become active
• Killer T cells attack cells infected with foreign antigens
• B cells make antibodies or immunoglobulins (Ig)
• Immunoglobulins fight infection by binding viruses and
preventing them from infecting healthy cells
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Physiology of Acquired Immunity
Immunoglobulins (Ig)
IgA
In mucous membranes of digestive system and respiratory
tract, tears, sweat, and saliva
IgD
In plasma and on surface of lymphocytes; possibly involved in B
cell maturation
IgG
Most common antibody; small amounts produced after first
exposure to pathogen, large amounts produced subsequently
IgE
In basophils and mast cells; mounts allergic response; fights
parasites
IgM
First antibody produced after exposure to pathogen; activates
complement system; on surface of red blood cells; responsible
for A, B, and O blood typing
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Physiology of Acquired Immunity
Autoimmune Disorders
• The immune system can malfunction and begin producing
antibodies against normal, healthy cells
• Examples: SLE, myasthenia gravis, rheumatoid arthritis,
MS, and type 1 diabetes
 Each disorder affects specific tissues, depending on the
type of antibodies produced and the cells they attack
 Type 1 diabetes is caused by an autoimmune process
that destroys beta cells that produce insulin in the
pancreas
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Physiology of Acquired Immunity
Allergic Reactions
• Immune system mediates allergic reactions; also called
hypersensitivity reactions
• Four types of hypersensitivity reactions (Type I, II, III, IV)
• Type I reactions cause anaphylaxis; can be life threatening
if not treated immediately
 Anaphylaxis: process mediated by antibodies,
basophils, and mast cells
 Causes swelling of airways, blood vessel dilation, shock
• Type II reactions stimulate the complement system; occur
when the wrong type of blood is given to a patient
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Physiology of Acquired Immunity
Allergic Reactions (continued)
• Type III reactions involve toxins and antibodies
• Type IV reactions involve killer T cells
 Also called delayed responses; take 12–72 hours to
occur
 Example: tuberculin skin test for tuberculosis
 When drugs cause Type IV reactions, hives or itchy rash
occur
Not harmful if drug is stopped
Can progress to anaphylaxis if drug is continued
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Immunization
Immunization
• Uses acquired immunity to fight specific diseases
• Natural immunization occurs when the body is exposed to
foreign antigens in daily life
 Produces antibodies against foreign antigens
 Can quickly defend and protect from getting sick again
• Artificial immunization occurs when an antigen is
intentionally introduced to the body via vaccination
 Builds a defense in advance of disease exposure
 Can be accomplished through active or passive means
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Immunization
Two Types of Artificial Immunization
• Active immunity
 The body is exposed to an antigen or part of an antigen;
natural immune response makes antibodies
 Vaccines use active immunity to prevent disease; body
introduced to killed, weakened, or partial antigens
 Some vaccines (called live attenuated vaccines) use live,
weakened pathogens to produce an immune response
• Passive immunity
 Antibodies introduced into bloodstream naturally
(pregnancy) or artificially (injecting immunoglobulins)
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Immunization
Vaccination
• Used to reduce and prevent life-threatening diseases
 Polio, smallpox, measles, and influenza
• Several vaccines require multiple doses
• CDC publishes an Immunization Schedule for Adults (see
Figure 4.2)
• Healthcare professionals should be informed of
immunization schedules and stay current
 Recommended: hepatitis B and annual influenza shot
 BCG vaccine for tuberculosis may be required
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Immunization
Common Vaccines
• Most administered in physician’s office and inpatient
settings
 Vaccines Commonly Handled by Pharmacy Technicians
(see Table 4.2)
• More now administered in pharmacies: flu shots, travel
vaccines, pneumonia, and shingles
• Many pharmacies operate travel immunization clinics
 Common travel vaccines: hepatitis A, cholera, malaria
• Vaccines are fragile proteins
 Routes: usually injection; few in oral form
• Pharmacy technicians order, store, and prepare vaccines
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Immunization
Common Vaccines (continued)
• Many patients
now get their
annual flu shots
at their local
pharmacies
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Immunization
Common Vaccines (continued)
• Side Effects: fever, headache, stomach upset, local
injection site irritation, mild rash, and irritability
 Take acetaminophen 24–48 hours after immunization
to reduce symptoms
• No link between autism and preservatives in vaccines
• Cautions (prior to administration of vaccines):
 Patients receive written risk information; see VIS
 Patients sign consent form
 No vaccine for patients with egg allergy
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Immunization
Common Vaccines (continued)
• Cautions: storage and preparation unique for each vaccine
 Refrigerate or freeze most
Check for required temperature range
 Warm frozen vaccines to room temperature; then use
right away
 Take daily temperatures of refrigerators and freezers
 Use prepared vaccines within minutes to hours
 Do not prepare multiple doses
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Your Turn
Question 1: Many employers require pharmacy technicians to
get the BCG vaccine. What is the purpose of this vaccine?
Answer: The BCG vaccine immunizes healthcare workers who
have high risk of exposure to active tuberculosis.
Question 2: A traveler received a vaccine for cholera. During his
trip, the patient became ill with cholera. What may have caused
this to happen?
Answer: The patient may not have waited long enough to
allow the immune system to provide full immunity.
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Interferon Therapy
Interferons
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Used for variety of conditions, including MS and hepatitis
Costly; usually dispensed in specialty pharmacies
Protein products that degrade easily
Store in the refrigerator
Administration: inject when at room
temperature
 Slowly roll the product between
palms of hands to warm it
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Interferon Therapy
Multiple Sclerosis (MS)
• Autoimmune disorder; antibodies destroy myelin sheath
surrounding nerve cells
 Scars form, interfering with signal conduction of nerves
 Numbness in limbs, loss of nerve axons and white
matter in the brain, vision loss, and paralysis
 Relapsing-remitting MS is the most common type
Drugs for MS
• Interferons prevent progression and relapse
• No flu shot with interferon therapy
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Interferon Therapy
Hepatitis
• Inflammation of the liver caused by viral disease, alcohol
use, medications, poisons, or autoimmune diseases
• Hepatitis A transmitted by consuming contaminated food
or liquids; short-term, acute infection only
• Hepatitis B transmitted by sexual activity, contaminated
needles, infected blood products, or mother to infant
 Begins as acute infection that mimics flu-like symptoms
or is asymptomatic
 Can lead to chronic liver infection such as cirrhosis, liver
cancer, and liver failure
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Interferon Therapy
Hepatitis (continued)
• Hepatitis C transmitted by blood-to-blood contact
 High-risk populations include injection drug users,
homeless, and prison inmates
 Most patients develop chronic liver infection
Drugs for Hepatitis
• No treatment required for hepatitis A
• Vaccines prevent hepatitis A and B; healthcare workers
receive three-injection series for hepatitis B
• Interferons used for chronic infection in hepatitis B and C
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Immunosuppression
Organ Transplant
• When someone receives an organ transplant
 T cells detect and attack the foreign tissue
 B cells make antibodies against it
 The body will reject the implanted organ unless
immunosuppression starts right away
• Tissue typing is performed to match organ donation
 Reduces chance of organ rejection, but risk remains
• Graft versus host disease is when T cells in transplanted
organ attack the recipient’s body after transplant
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Immunosuppression
Immunosuppressants
• Medications that suppress immune system activity to
prevent rejection of a transplanted organ
• Indications: taken for life after receiving a transplant
 Also suppress autoimmune disorders such as
rheumatoid arthritis, SLE, and psoriasis
• Mechanism of Action: inhibit T cell and B cell activity
• Side Effects: sore throat, cough,
dizziness, nausea, muscle aches,
fever, chills, itching, and headache
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Immunosuppression
Immunosuppressants (continued)
• Serious Side Effects (rare): heart rhythm or blood pressure
changes, chest pain, unusual bleeding, bruising, anemia,
and hyperlipidemia
 Muromonab can cause severe pulmonary edema (fluid
accumulation in the lungs) on first dose
• Cautions: patients must minimize exposure to infection
due to higher risk
• Routes: IV; also oral, IM injections, and SC injections
 IV dosage forms require special handling and mixing
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Immunosuppression
Immunosuppressants (continued)
• Some IVs refrigerated; some protected from light
• Do not shake IVs; use within limited time from mixing
 Cyclosporine should be prepared in glass containers
• Special administration instructions
 Oral tacrolimus should not be taken with antacids
 Sirolimus can be taken with or without food consistently
 Some agents given as IV infusions; some given as IV
bolus injections
• Some agents have serious drug interactions
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Immunosuppression
Oral Corticosteroids
• Systemic oral agents with anti-inflammatory and
immunosuppressant properties; decrease fever, redness,
and swelling
• Modify immune response by slowing leukocyte function
• Indications (short term, high doses): hypersensitivity,
allergic reaction, and asthma exacerbations
• Indications (long term): protection from organ transplant
rejection and used for treatment of rheumatic and some
autoimmune disorders
• Side Effects: headache, dizziness, insomnia, and hunger
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Immunosuppression
Oral Corticosteroids (continued)
• Side Effects (long-term): change in normal metabolism,
facial swelling (moon face), major weight gain, fluid
retention, and fat redistribution to back and shoulders
(buffalo hump)
• Severe Side Effects: high blood pressure, loss of bone mass
(osteoporosis), electrolyte imbalance, cataracts, glaucoma,
insulin resistance (diabetes), and steroid-induced psychosis
• Routes: all oral; some IM and IV
• Cautions: do not stop using abruptly;
causes increased risk of infection
 Can stunt growth in children if used long term
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Immunoglobulins, Antitoxins, and Antivenoms
Immunoglobulins
• Provide artificial passive immunity quickly through injected
exogenous antibodies
 Immunity only lasts a few months; no boosters required
• Indications: rabies, tetanus, chickenpox, shingles, and RSV
Antitoxins and Antivenoms
• Antibodies in agents combine with the toxin or venom to
neutralize it
 Example: Rh factor immune globulin used for negativeblood-type woman carrying a positive-blood-type
child
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Immunoglobulins, Antitoxins, and Antivenoms
Antivenoms (continued)
• Also called antivenins
• Indications: spider bites (black widow spiders); snakebites
(rattlesnakes, copperheads, and North American coral
snakes)
• Route: most by IV within 4 hours of the bite
• Prepare orders immediately and rush to ER for
administration
 Warm refrigerated agents by gently
rolling vials between the palms of the
hands
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Your Turn
Question 1: What is the purpose for storing interferons in the
refrigerator?
Answer: Interferons are fragile proteins that easily degrade.
Refrigerating these agents helps keep the proteins from
breaking down.
Question 2: A patient is at a county fair. She is wearing a face
mask and often uses a hand sanitizer. What is the likely reason
for her precautions?
Answer: The patient is likely being treated with
immunosuppressants and is at increased risk of infection.
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Herbal and Alternative Therapies
• Limited herbal and alternative therapies available for
autoimmune disorders, hepatitis, or immunosuppression
• Vitamin D supplementation may help decrease risk of MS
in women; no recommended dose
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Summary
• Immunization uses acquired immunity to protect against
specific diseases
• Vaccinations trigger production of antibodies to protect
against specific diseases
• Interferon therapy is used to treat autoimmune disorders
• Immunosuppressants inhibit the immune system from
attacking transplanted tissue after organ transplant
• Immunoglobulins in antitoxins and antivenoms provide
rapid immunity for specific diseases
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