Drugs for Bacterial Infections

1
Drugs for Bacterial Infections

• Chapter 34

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Key Terms to Know Understand
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Classifying Bacteria

• Gram stain
• Positive
• Negative
• Cellular shape
• Rods bacilli
• Spheres cocci
• Spirals spirilla

• Ability to use oxygen
• Aerobic
• anaerobic
• Chemical class
• Similarities in antimicrobial properties and side
  effects
• Mechanism of action
• Pharmacologic classes

4
Acquired Resistance

• Rapid replication of microorganisms can result in
  genetic code mutations
• Mutation can result in drug resistance to certain
  microorganisms
• Discuss the role of antibiotic therapy in the
  development of drug resistance.
• Identify strategies to reduce antibiotic
  resistance.

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Indications for Antibiotic Therapy

• Describe the two overarching situations in which
  antibiotic therapy would be indicated/appropriate.
  

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Brief Case Study

• Mr. J., a 76 year-old-male, presented to the ED
  with a three day history of progressively
  elevated fever. Today the fever is 102.5 F. He
  complains of generalized weakness and extreme
  fatigue. He states he has not slept well and
  doesnt have much of an appetite. The physical
  exam does not provide insight into the specific
  cause of the fever. Although, his CRP and ESR
  are elevated and the WBC value is 18.5.

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Case Study Questions

• What additional diagnostic tests should be
  ordered?
• What pharmacologic management would you
  anticipate to be ordered? Why?

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Single-drug vs. Multi-drug Therapy

• Most often a single antibiotic will be used.
• Multi-drug therapy
• Can cause antagonism
• Indicated for
• Infection with several different organisms
• Severe infection requiring therapy before CS
  results
• TB, HIV

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Superinfections

• Normal flora destroyed ? opportunity for
  proliferation of other bacteria
• more likely with use of broad-spectrum agents
• Example candida albicans
• Host flora become pathogenic
• Occurs in immunocompromise
• Example pneumocystis pneumonia

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Antibiotic Selection

• Microorganism must be sensitive to effects of
  drug
• Influenced by host factors
• Health of immune system and phagocytic cells
• Age
• Pregnancy status
• Genetics

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Antibacterial Agents

• Chemical Class
• Penicillinins
• Cephalosporins
• Tetracyclines
• Macrolides
• Aminoglycosides
• Fluoroquinolines
• Sulfonamides

• Develop a table to include
• MOA
• Prototype and examples
• Indications for therapy
• Common adverse effects
• Nursing considerations
• Key teaching points

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Miscellaneous Antibiotics

• Review
• Table 34.9 Miscellaneous Antibacterials, p.
  503
• Discuss why several antibacterial agents are
  placed in this class.

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Antibiotic TherapyGeneral Nursing Considerations

• Assess previous drug reactions hypersensitivity
• Obtain specimens before therapy
• Assess VS, lytes, RFTs, LFTs, CBC, Coag studies
• Check for drug interactions
• Observe for
• Allergic reaction
• Antibiotic associated pseudomembranous colitis
• Superinfections
• Nephrotoxicity ototoxicity

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Antibiotic TherapyGeneral Client Teaching

• Medic alert for allergies
• Complete full course of antibiotics
• Immediately report s/s of antibiotic associated
  pseudomembranous colitis
• Maintain fluid intake
• Protect from sun exposure if applicable

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Tuberculosis

• Microorganism invades lungs, but may also travel
  to other sites.
• Mycobacterium tuberculosis will active the immune
  system which isolates the bacterium by creating a
  surrounding wall.
• Cavities (tubercles) develop containing the
  bacterium, which becomes dormant.
• Mycobacterial cell wall resistant to penetration
  by anti-infective drugs.

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Anti-infective Therapy for TB

• Long term
• 6 to 12 month minimum
• Compliance is essential
• Multiple concurrent drug therapy
• Two broad categories
• Primary (First line)
• Secondary (Second line)
• Used for prophylaxis as well as treatment

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Anti-tuberculosis Therapy NCs

• Assess for presence or history of TB test,
  sputum culture, close contact with infected
  person
• Possible contraindications alcohol use, AIDS,
  liver disease, kidney disease
• Cautious renal dysfunction, pregnancy,
  lactation, history of convulsive disorder
• Monitor uric acid
• Ethambutol contraindicated if optic neuritis.

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Anti-tuberculosis Therapy Client Teaching

• Immediately report s/s of liver dysfunction
• Take supplemental Vitamin b6
• Isoniazid avoid foods with tyramine
• Complete full course of treatment
• Frequently wash hands
• Cover mouth when coughing/sneezing
• Decreases effectiveness of oral contraceptives
  use alternate contraception