Introduction to Clinical Pharmacology Chapter 49 Immunologic Agents

Immumity The ability of the body to identify and resist microorganisms that are potentially harmful. Enables the body to fight or prevent infectious disease and inhibit tissue and organ damage. Vaccines help the body to boost this process of gaining immunity. The immune system has two distinct, but overlapping, mechanisms with which to fight invading organisms: • Cell-mediated defenses (cell-mediated immunity [CMI]) • Antibody-mediated defenses (humoral immunity)

Cell-Mediated Immunity Results from activity of leukocyte actions, reactions, and interactions that range from simple to complex Depends on actions of T lymphocytes—responsible for delayed type of immune response The T lymphocytes defend against viral infections, fungal infections, and some bacterial infections. T lymphocytes and macrophages (large cells that surround, engulf, and digest microorganisms and cellular debris) work together in CMI to destroy the antigen. CMI reduced in acquired immunodeficiency syndrome (AIDS): body is unable to protect against viral, bacterial, fungal infections

Humoral Immunity In humoral immunity: protects the body against bacterial and viral infections. B lymphocytes produce circulating antibodies to act against foreign substance Based on antigen–antibody response Antigen: protein that stimulates the body to produce antibodies Antibody: globulin produced by B lymphocytes as defense against an antigen Once manufactured, antibodies circulate in the bloodstream, sometimes only for a short time, but in other cases for the lifetime of the person.

Active and Passive Immunity Involve use of agents that stimulate antibody formation Injection of ready-made antibodies found in serum of immune individuals or animals

Active and Passive Immunity: Active Immunity #1 Two types of active immunity: Naturally acquired active immunity Artificially acquired active immunity Naturally acquired active immunity: Occurs when person is exposed to disease and experiences disease, and body manufactures antibodies to provide future immunity to the disease

FIGURE 49.2 A child sickened by chickenpox acquires active immunity naturally from the varicella virus.

Active and Passive Immunity: Active Immunity #2 Artificially acquired active immunity: Occurs: individual is given killed or weakened (attenuated)antigen—stimulates formation of antibodies against the antigen With attenuated-individual may experience a few minor symptoms of the disease or even a mild form of the disease Requires periodic booster injections to keep adequate antibody level circulating in blood Booster injection: additional dose of vaccine to boost production of antibodies to level to maintain desired immunity (influenza vaccine)

Active and Passive Immunity: Passive Immunity Obtained from administration of immune globulins or antivenins Provides individual with ready-made antibodies from another human or an animal Provides immediate immunity to invading antigen Lasts for only a short time

Immunologic Agents Capitalize on body’s natural defenses: Stimulate immune response and create within-body protection to specific disease Supply ready-made antibodies to provide passive immunity

Immunologic Agents: Actions and Uses #1 Vaccines and toxoids: Vaccines: contain either attenuated (weakened) or killed antigen, developed to create immunity to certain diseases Toxin: poisonous substance produced by a bacterium (such bacterium causing tetanus) Capable of stimulating body to produce antitoxins

Immunologic Agents: Actions and Uses #2 Vaccines and toxoids are used for: Routine immunization of infants and children Immunization of adults against tetanus Adults at high risk for certain diseases Children or adults at risk for exposure to a particular disease Immunization of prepubertal girls or nonpregnant women of childbearing age against rubella

Immunologic Agents: Actions and Uses #3 Immune globulins and antivenins: Immune globulins: solutions obtained from human or animal blood containing antibodies formed by body to specific antigens The onset of protection is rapid but of short duration (1 to 3 months). Antivenins: used for passive, transient protection from toxic effects of bites by spiders and snakes The most effective response is obtained when the drug is administered within 4 hours after exposure.

Immunologic Agents: Adverse Reactions #1 Vaccines and toxoids: Chills; fever Muscular aches and pains; rash; lethargy Pain and tenderness at the injection site Hypersensitivity reaction

Immunologic Agents: Adverse Reactions #2 Immune globulins and antivenins(made in equine or rabbit serum): Immune globulins: Urticaria; angioedema; erythema; malaise; nausea; diarrhea, headache, chills, fever Antivenins: Hypersensitivity; apprehension; flushing; itching Urticaria; edema of the face, tongue, and throat; dyspnea; vomiting; cyanosis; collapse

Immunologic Agents: Contraindications and Precautions #1 Vaccines and toxoids: Contraindicated in patients with known sensitivity and with acute febrile illnesses, leukemia, lymphoma, immunosuppressive illness or drug therapy, nonlocalized cancer Immunologic agents: Used with extreme caution in individuals with a history of allergies

Immunologic Agents: Contraindications and Precautions #2 Immune globulins contraindicated in patients with: History of allergic reactions after administration of human immunoglobulin preparations Isolated immunoglobulin A deficiency Antivenins contraindicated in patients with: Hypersensitivity to horse serum or any other component of serum

Immunologic Agents: Interactions #1 Vaccines and toxoids: Corticosteroids; antineoplastic drugs; radiation therapy: depress immune system Salicylates administered with varicella vaccination: risk for Reye syndrome develops

Immunologic Agents: Interactions #2 Immune globulins and antivenins: Antibodies in immune globulin preparations: Interfere with immune response to live virus vaccines, particularly measles, others, such as mumps and rubella recommended that the live virus vaccines be administered 14 to 30 days before or 6 to 12 weeks after administration of immune globulins.

Nursing Process: Assessment #1 Preadministration assessment: Obtain allergy history before administration of any vaccine Tell primary health care provider before vaccine is given if individual is known to have allergies of any kind Determine whether patient has any conditions that contraindicate administration of agent

Nursing Process: Assessment #2 Ongoing assessment: Ask patient to stay in clinic or office for observation for about 30 minutes after injection to observe for signs of hypersensitivity Keep emergency resuscitation equipment available to use in event of severe hypersensitivity reaction

Nursing Process: Diagnoses Acute Pain related to adverse reactions (pain and discomfort at the injection site, muscular aches and pain) Individual Effective Self-Health Management related to timing of immunization schedule

Nursing Process: Planning Expected outcome Optimal response to immunologic agent Support of patient needs related to the management of common adverse drug effects Understanding of and compliance with prescribed immunization schedule

Nursing Process: Implementation #1 Promoting an optimal response to therapy: Read directions enclosed with vaccine Document following information in patient’s chart or form: Date of vaccination; route and site; vaccine type; manufacturer Lot number and expiration date Name, address, and title of individual administering vaccine

Nursing Process: Implementation #2 Monitoring and managing patient needs: Acute pain Increase fluids in diet; allow for adequate rest Keep atmosphere quiet and nonstimulating Treat local irritation at injection site with warm or cool compresses, depending on patient’s preference

Nursing Process: Implementation #3 Monitoring and managing patient needs (cont.) Individual effective therapeutic regimen management: Encourage parents to have their infants and young children receive immunizations Provide parents with copy of the record of immunizations

Nursing Process: Implementation #4 Educating the patient and family: Discuss risks of contracting vaccine-preventable diseases, benefits of immunization Instruct parents to bring immunization records to all visits Provide date for return for next vaccination Discuss adverse reactions, methods to combat these reactions

Nursing Process: Evaluation Therapeutic effect is achieved Disease does not present itself Adverse drug reactions managed successfully Patient or parents/guardians comply with the immunization schedule Patient and family express understanding of need for immunizations

Question #1 Is the following statement true or false? Immunity is the body’s ability to identify and resist potentially harmful microorganisms.

Answer to Question #1 True Immunity is the body’s ability to identify and resist potentially harmful microorganisms. There are two types of immunity: cell mediated and antibody mediated.

Question #2 Is the following statement true or false? Cell-mediated immunity involves the B lymphocytes.

Answer to Question #2 False Cell-mediated immunity involves the T lymphocytes.

Question #3 Is the following statement true or false? The active and passive immunity of vaccinations focus on the antibody-mediated immunity.

Answer to Question #3 True The active and passive immunity of vaccinations focus on the antibody-mediated immunity.