Antifungal, Antiviral, Immunizing Agents

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Antifungal, Antiviral, Immunizing Agents

• Unit 18

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Objectives

• Describe the four general classes of
  antiretroviral agents.
• Differentiate between active and passive
  immunization.
• State the general recommendations of
  immunization.
• Define vaccine, toxoid, immune globulin, specific
  immune globulin, antitoxin.

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Viruses

• Viruses are parasitic, minute organisms that
  invade normal cells and cause disease.
• They depend on the host for their nutrition,
  metabolism, and reproduction.
• Over 300 viruses have been isolated!
• Examples smallpox, herpes, Epstein-Barr, rabies,
  Hep. B, HIV

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Antigens

• Foreign substances that invade a host
• 4 phases associated with the immune response to
  an antigen
• 1. Recognition of the invader
• 2. Amplification of the defenses (WBC)
• 3. Attack phase
• 4. Slowdown phase number of defenders return to
  normal following the attack

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Specialized Defenders

• Lymphocytes T cells and B cells
• Helper T cells identifies the enemy and sends
  out the troops
• Killer T cells kills cells of the body that have
  been invaded by antigens
• B cells produces antibodies

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Antifungal Agents

• Destroy or inhibit the growth of fungi
• Not effective against bacteria or viruses
• Treat skin and mucous membrane infections
• Contraindicated in patients with bone marrow
  depression or renal function impairment

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Antiviral Agents

• Developed to combat specific viral diseases
• Ex. Acyclovir (Zovirax)
• Used to treat Herpes Simplex types 1,2
• Famciclovir (Famvir)
• Used to treat shingles, genital herpes

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Antiretroviral Agents

• Consist of a group of drugs used to treat HIV
  infection
• 4 general classes
• 1. nucleoside reverse transcriptase inhibitors
• 2. non-nucleoside reverse transcriptase
  inhibitors
• 3. protease inhibitors
• 4. fusion inhibitors

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Nucleoside reverse transcriptase inhibitors
(NRTIs)

• Interrupt an early stage of virus replication
• May slow the spread of HIV infection in the body
  and delay the onset of opportunistic infections
• Will not prevent the transmission of HIV to other
  people

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Non-nucleoside reverse transcriptase inhibitors
(NNRTIs)

• Inhibit HIV production by binding directly onto
  reverse transcriptase and preventing the
  conversion of RNA to DNA

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Protease Inhibitors

• Agents that interrupt virus replication at a
  later step in the life cycle of the virus
• Prevent HIV from being assembled and released
  from an infected cell into a healthy cell

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Fusion (entry) Inhibitors

• Prevent HIV from entering healthy T-cells in the
  body
• Thus, HIV is unable to bind to the surface of T
  cells and gain entry into the healthy cells

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Immunization

• Immunity state of being protected from or
  resistant to a particular disease due to the
  production of antibodies
• Immunity involves the antigen-antibody response
• Antigens vs. antibodies
• Immunization process of inducing or providing
  immunity by administering an agent

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Immunizations

• Active production of an antibody in response to
  the administration of a vaccine
• Passive temporary immunity by the administration
  of performed antibodies or antitoxins
• Agents used include Igs and antitoxins

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Immunobiologics

• Components include
• 1. Suspending fluid sterile water or saline
• 2. Preservatives, stabilizers, antibiotics used
  to inhibit or prevent bacterial growth in viral
  culture or the final product allergic reactions
  may occur if the patient is sensitive to one of
  the additives
• 3. Adjuvants aluminum compound that enhances
  immune response to vaccines

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Immunizing Agents

• Vaccine suspension of live or dead microorganism
• Toxoid bacterial toxin that has been rendered
  nontoxic
• Immune globulin sterile solution containing
  antibodies from human blood
• Antitoxin solution of antibodies derived from
  the serum of animals immunized from specific
  antigens

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Immunization During Pregnancy

• Live viruses are not generally given to pregnant
  women or to those likely to become pregnant
  within three months after receiving the vaccine

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Antigens

• Substances that induce the formation of
  antibodies.