Exam 19 - Drugs Affecting the Immune System

Drugs Affecting the Immune System

• Vaccines: Preparations of killed, weakened, or synthetic bacteria/viruses to stimulate antibody production against specific diseases.
  • Mechanism: Stimulates the immune system to create antibodies for future infection protection.
  • Efficacy: Less effective than naturally contracting the disease; may require multiple doses and booster shots for sustained immunity.
  • Types:
    • Inactivated: Killed organisms (e.g., polio, hepatitis A, rabies)
    • Attenuated: Weakened live organisms (e.g., MMR, varicella); contraindicated in those with active infections and pregnancy.
    • Toxoids: Modified non-toxic toxins (e.g., diphtheria, tetanus)
    • Biosynthetic: Made using genetic material (e.g., Hepatitis B)
  • Schedules: Multiple injections to ensure sufficient B cell sensitization. DTaP (diphtheria, tetanus, pertussis) vaccine is given at specific ages, with boosters at later intervals (2, 4, 6 months, 15-18 months, 4-6 years, 11 years, then every 10 years).
  • Distinction: Vaccine is the injection; immunization is the successful outcome.

Antibody Titer

• Purpose: Measures the amount of antibodies in the blood to determine the strength of immunity to a specific organism.
  • Interpretation: A zero titer indicates no antibodies; a titer of 32 signifies good immunity.

Seasonal Flu Vaccine

• Recommendations: Annual vaccination for all ages, especially immunocompromised individuals.
• Strain Variability: The vaccine is updated yearly to correspond with the prevalent strain.

Side Effects

• Minor: Sore arm, minor swelling, low-grade fever.
• Severe: Can range from hives to seizures to anaphylactic shock.

Nursing Implications and Patient Teaching

• Assessment: Obtain complete medical history, including immunodeficiency, pregnancy status, and allergy information.
  • Assess for symptoms of illnesses which may necessitate vaccine delay.
• Teaching: Provide information about possible side effects (localized reactions, pain), comfort measures (e.g., cool compresses), and when to notify the healthcare provider (e.g., fever).

Immunomodulation

• Definition: Altering the immune response, either stimulating (enhancing) or suppressing it.
  • Purpose: In cases of organ transplants and autoimmune diseases.
  • Immunostimulants: Stimulate a weak immune system; vaccines are an example.

Selective Immunosuppressants for Autoimmune Diseases & Transplant Rejection

• Overview: Suppress the immune response in autoimmune disorders (e.g. rheumatoid arthritis, psoriasis) or transplant rejection situations.
• Types of Immunosuppressant Drugs:
  • Nonselective: Corticosteroids (e.g., prednisone), cancer chemotherapeutic drugs (e.g., methotrexate)
  • Selective: Disease-modifying antirheumatic drugs (DMARDs), e.g. adalimumab, etanercept.
• Immunosuppressant drugs:
  • Antiproliferative Drugs: Slow lymphocyte growth (e.g. azathioprine)
    • Reduce lymphocytes by inhibiting purine metabolism crucial for DNA synthesis and cell division

Adverse Effects of Immunosuppressants

• General: Gastrointestinal (GI) problems, rashes, possible cancer (especially skin cancer), liver toxicity, electrolyte imbalances.
• Specific to Calcineurin Inhibitors: Increased blood cholesterol and blood glucose; gingival hyperplasia (gum overgrowth).
• Specific to Selective Immunosuppressants: Increased risk of skin cancer; increased risk of liver toxicity with acetaminophen/alcohol.

Drug Interactions

• Important: Check with a pharmacist or drug reference for interactions. Cyclosporine has numerous interactions (57 serious and 37 moderate).

Nursing Implications

• Assessment: Complete history, physical exam, including a complete drug history and infection screening, lab values, including baseline CBC, chemistry, platelets, etc.
• Teaching: Emphasize self-monitoring, symptom reporting, vaccine precautions, medication administration, and safety measures (e.g., avoiding grapefruit, timing the use of medications).