Drugs for Bacterial, Viral, and Fungal Infections Infectio

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Drugs for Bacterial, Viral, and Fungal Infections
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Infection

• How do we get infected?
• Role of our immune system
• Who are they?
• What can we do to help?
• Chemotherapeutics
• Antibiotics
• Antiviral
• Antifungal

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Antibiotics

• Bacteria good or bad?
• Unicellular
• Must feed from a host
• How are Antibiotics classified?
• Spectrum of activity narrow or broad
• Bactericidal or bacteriostatic

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Antibiotics Which One to Choose?

• Identification of the organism
• Taking a sample (throat culture)
• Drug sensitivity
• Testing of culture to determine which
  chemotherapeutics to use
• Host factors
• Status of immune system
• Site and concentration of infection
• age

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Antibiotics that Inhibit Cell Wall Synthesis

• Penicillin
• Passes thru the cell wall of the infected cell
  and inhibits construction of the bacteriums cell
  wall
• Can be administered orally or by injection
• Ear infections, pneumonia, skin infections,
  urinary tract infections
• Adverse reactions include rashes, anaphylactic
  reactions, swelling

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Antibiotics that Inhibit Cell Wall Synthesis
cont.

• Cephalosporins
• Broader application base than penicillin
• Used for skin, soft tissue infections,
  respiratory infections, meningitis
• Adverse reactions are hypersensitivity
• Often used when allergic reaction to penicillin

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Antibiotics that Inhibit Protein Synthesis

• Tetracyclines
• Broad-spectrum class
• Lyme disease, syphilis, acne
• Adverse reaction to calcium (dairy), iron, zinc,
  magnesium, aluminum
• May cause GI distress, increase sensitivity to sun

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Antibiotics that Inhibit Protein Synthesis

• Macrolides (erythromycin)
• Alternative choice to penicillin (allergy)
• Oral or IV
• Adverse reactions GI disturbance, potential
  interactions with other drugs
• Clindamycin
• Unique in that it has antibacterial activity
  against microbes (anaerobes) that survive without
  O2
• Can cause diarrhea

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Antibiotics that Inhibit DNA Synthesis

• Fluoroquinolones
• Broad-spectrum bacterial infections
• Inhibit the coiling process of the bacterial DNA
• Typically NOT used with children associated
  with tendon tissue weakening

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Antibiotics that Inhibit Folic Acid Synthesis

• Sulfonamides (sulfa drugs)
• Developed prior to penicillin
• Used infrequently
• Used to treat urinary tract infections

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Antibiotic Generic Brand Action
penicillin penicillian amoxicillian Ampicillin Amoxil, Keflex I bacterial CW Synthesis
1stgen Cephalosporin cephalexin Keflex
2nd gen Cephalosporin Cefprozil 2nd Cefzil, Ceclor
3rd gen Cephalosporin Cefixime 3rd Suprax
4th gen Cephalosporin Cefepime 4th Maxipime
Aminogylocide Tobramycin Nebcin, Amikin I bact pro syn
Flouroquinolone Ciproflacin Cipro, Levaquin I bac DNA syn
Tetracycline Tetracycline Minocin I bac pro syn
Macrolide erthromycin Zithromax
Sulfonamide sulfamethoxazole Bactrim I bac folic acid syn
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Other Qualities of Antibiotics

• Adverse Effects
• Hypersensitivity
• Diarrhea
• GI distress
• Itching
• Rashes
• Ultraviolet sensitivity

• Antibiotic Resistance
• Reduced efficacy due to overuse
• Excessive use of antibiotic soaps
• Raised resistance levels of bacteria

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Antiviral Agents

• Infection a desire to replicate itself via DNA
  or RNA
• Virus can mutate into more serve condition
• Viral agents can persist for weeks
• Limited Tx regimes
• See Pg 127 for common examples

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Treatment Protocols

• Oral Medications
• Acyclovir (herpes)
• Inhibits viral DNA replication
• Docosanol (Abreva) OTC medication for cold
  sores
• Zanamivir (Relenza) used to treat influenza
• Vaccines
• Injection of an inactivated virus (unable to
  replicate), causes body to make antibodies

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Antifungal Agents

• Most common seen on epidermis
• Needs to survive warmth, moisture, darkness
• Where do we see most fungal infections?
• Tinea (skin)
• Tinea capitis (ringworm of scalp)
• Tinea corporis (trunk area)
• Tinea cruris (jock itch)
• Tinea pedis (athletes foot)
• Onychomycosis (nail fungus)

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Management of Fungal Infections

• Prevent infection from becoming systemic
• Spread through direct/indirect contact
• Poor hygiene
• Medications
• Oral or topical (table 9-4)
• Takes 3-8 weeks for successful tx
• Can re-appear frequently