Baker's Exam #1; Objectives 11-21

  1. Describe the differences in bacterial spectrum among 1st, 2nd, and 3rd generation cephalosporins
    • 1st gen cephs: only gram + aerobes (but best at this category!)
    • 2nd gen cephs: WHAT WE'LL PRESCRIBE: effective against GRAM + AEROBES, gram + anaerobes, and GRAM - ANAEROBES (best anaerobe coverage)
    • 3rd gen cephs: pretty much useless- oral agents provide NO effectiveness against anaerobes. May treat gram + aerobes
  2. Explain why erythromycin causes so mush GI upset compared to newer macrolides
    ERYTHROMYCIN causes gastrointestinal upset because it causes GUT MOTILITY (clarithromycin does a little and azithromycin causes none). Mechanism = motilin receptor agonist in the gut and gallbladder. (Erythromycin is being studied for use as a prokinetic.)
  3. Explain advantages of clarithromycin over azithromycin.
    • Clarithromycin has not been overused compared to azithromycin (z-pack)
    • CLARITHROMYCIN retains ACTIVITY AGAINST VIRIDANS GROUP STREP and ANAEROBES (what we need to target in dental infection!)
  4. Explain disadvantages of clarithromycin over azithromycin
    • clarithromycin inhibits CYP 3A4, so there are more drug interactions than with azithromycin
    • clarithromycin has a bad taste
  5. Identify 6 major drug interactions with macrolides (will get handout for this)
    • 1. Anticoagulants- increased risk of bleeding disorders. Monitor pt.
    • 2. Bromocriptine- increase in bromocriptine toxicity. Consult physician
    • 3. Carbamazapine- toxic effects. Avoid concurrent use.
    • 4. Cyclosporine- increase in renal toxicity. Consult physician
    • 5. Diltiazem and verapamil- prolonged QT interval with risk of sudden death. Avoid concurrent use.
    • 6. Theophyllines- avoid concurrent use if possible. SBE ok.
  6. Recognize and categorize the 6 orally available fluoroquinolones
    • Gatafloxacin- limited use against gram - anaerobes
    • Levofloxacin- best fluoroquinolone against gram + aerobes
    • Moxafloxacin- limited use against gram -anaerobes
    • Ofloxacin
    • Sparfloxacin- longest half-life
    • Trovafloxacin- use limited to life-threatening conditions due to liver toxicity. Best fluoroquinolone against gram - anaerobes.
  7. Describe adverse effects or contraindications for fluoroquinolones
    • Arthropathies: contraindicated for children, adolescents, pregnant or lactating
    • CNS stimulation/toxicity
    • GI Disturbances
    • Photosensitivity
    • Black box warning, achiles tendon
  8. List the four requirements for CDIC
    • Presence of Clostridia difficile in GI tract
    • Altered GI flora
    • Presence of Toxin A and B (must have receptors in the gut)
    • Predisposing factors
  9. List the 5 risk factors for CDIC
    • Recent hospitalization
    • Recent broad-spectrum antibiotic use
    • History of Colitis
    • Advanced age
    • Recent instrumentation of the lower bowel
  10. List signs and symptoms of CDIC
    • Profuse, watery diarrhea 1-20 times/day
    • Bloody diarrhea in 5-10% of cases
    • Foul smelling
    • Abdominal cramping
    • Nausea
    • Fever
    • Leukocytosis
  11. List five drug interactions w/ metronidiazole
    • Ethanol
    • Anticoagulants
    • Lithium
    • Disulfuram
    • Phenytoin
Card Set
Baker's Exam #1; Objectives 11-21
Baker's Exam #1; Objectives 11-21