Drugs for Inflammation, Allergies, and Immune Disorders

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Drugs for Inflammation, Allergies, and Immune
Disorders

• Chapter 21

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Inflammation

• Defense mechanism designed to contain injury or
  destroy foreign agent
• Possible triggers injury, heat, invading
  microorganisms, death of cells
• Signs Redness, swelling, pain, warmth
• May be acute (resolves in 8-10 days), chronic
  (can persist for years), or seasonal (such as
  with spring hay fever)

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Histamine

• Stored and released by mast cells
• Initiates inflammatory response in seconds
• Leads to
• Dilation of blood vessels, allowing immune system
  components to leak out
• Leakage can lead to swelling
• Itching
• Smooth muscle constriction
• Interacts with H1 receptors primarily in
  epidermis, vessels, and bronchi, and H2 receptors
  in stomach

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Allergic Rhinitis (Hay fever)

• Allergy- exaggerated response of immune system,
  results in release of histamine which causes
  inflammation
• Allergic Rhinitis causes inflammation of mucous
  membranes in nose, throat, eyes, and airways
• Sx tearing, sneezing, nasal congestion, itching
  throat
• Numerous possible causes (pollen, mold, dust
  mites, animal dander, other)

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Allergic Rhinitis Treatment

• Preventers- used for prophylaxis
• Antihistamines
• Glucocorticoids
• Mast cell stabilizers
• Relievers- provide immediate, temporary relief
• decongestants

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Histamine1 Receptor Antagonists(Antihistamines)

• Sedating or non-sedating types
• Best used prophylactically for allergies
• Other uses vertigo, motion sickness

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1st Generation Antihistamines (diphenhydramine)

• Treats allergy and common cold sx by histamine 1
  receptor blockage
• SE drowsiness, dry mouth, increased heart rate,
  constipation

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2nd Generation Antihistamines (fexofenadine)

• Same MOA as diphenhydramine (blocks H1 receptors)
• SE same, except less drowsiness

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Intranasal Glucocorticoids (fluticasone)

• Glucocorticoids- hormones secreted by adrenal
  gland which have strong antiinflammatory effects
• Fluticasone and others are synthetic versions
• SE nasal irritation, bleeding

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Decongestants (oxymetazoline and pseudoephedrine)

• Mimic fight or flight response (these are
  sympathomimetics)
• Intranasal or oral
• Intranasal (oxymetazoline)- produce very rapid,
  local effect
• Rebound congestion- excessive secretionof mucus
  once drug wears off, common with prolonged use
• Oral (pseudoephedrine)- slower onset, less
  effective, more systemic SE
• No rebound congestion

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Drugs for Systemic Inflammation and Arthritis

• Nonsteroidal Anti-Inflammatory Drugs
• Systemic Glucocorticoids
• Immunosuppressants

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Nonsteroidal Antiinflammatory Drugs (naproxen)

• Inhibit prostaglandin synthesis
• Prostaglandin release leads to pain, fever, and
  inflammation
• Uses arthritis, gout, menstrual cramps
• SE GI upset, prolonged bleeding

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Systemic Glucocorticoids (prednisone)

• Suppress histamine and prostaglandins
• Suppress immune system
• Potent antiinflammatory activity
• Uses arthritis, bronchospasm of asthma, allergic
  reactions
• SE ? blood sugar, cataracts, osteoporosis,
  infection, stunted growth, other
• Guidelines limit to short term use if possible
  if not, try alternate day therapy

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Immunosuppressants (cyclosporine)

• Suppresses immune system to prevent transplant
  rejection
• Also useful for other diseases of severe
  inflammation such as rheumatoid arthritis
• SE infection, cancer

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Vaccines

• Suspension of one of the following
• Killed microbes
• Attenuated (weakend) microbes
• Toxoids (bacterial toxins) that have been made
  safe
• Result in immune response
• Immune system remembers the exposure and can
  produce large amounts of antibodies to fight
  infection if re-exposure occurs
• SE fever, inflammation at injection site
• Generally not given during an acute illness
• Vaccines are safe for pregnant women (except MMR
  and varicella, which are attenuated)
• When in doubt, re-immunize