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Aminopenicillin

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Aminopenicillin, Third Generation Penicillin

  • See Also
  1. Penicillin
  2. Amoxicillin
  3. Ampicillin
  4. Augmentin
  5. Unasyn
  1. Ampicillin
    1. Child: 50-200 mg/kg/day IV divided qid
  2. Amoxicillin
    1. Maximum dose: Maximum dose: 3-4 grams/day
    2. Adult: 875 to 1000 mg orally twice daily
    3. Child
      1. Low dose: 45 mg/kg/day divided twice daily
      2. High dose: 90 mg/kg/day divided twice daily
  1. Ampicillin Sulbactam (Unasyn)
    1. Adult: 1.5-3 grams IV every 6 hours
  2. Amoxicillin Clavulanate (Augmentin)
    1. Adult: 875 mg PO bid
    2. Child: 45 mg/kg/day divided PO bid
  • Mechanism
  1. Same as for Natural Penicillins
  2. Amino Acid side group
    1. Hydrophilic, and allows penetration via pores in Gram Negative Bacterial outer membrane
  3. Clavulanic acid and sulbactam bind Beta-Lactamases and block Penicillinases
  • Pharmacokinetics
  1. Keep Augmentin suspension refrigerated
  2. Clavulanate suspension breaks down at room Temperature
    1. Turns brown with breakdown
    2. Loses 90% of potency after 2 days at room Temperature
  • Pathophysiology
  • Bacterial Resistance Mechanisms Overcome
  1. Beta-Lactamase Production
  2. Alteration of Penicillin binding Protein
  • Activity Spectrum
  1. General
    1. Gram Positive Cocci
    2. Gram Negative Rods
    3. Spirochetes (e.g. Treponema pallidum)
  2. Conditions
    1. Otitis Media
    2. Sinusitis
    3. CNS Infection
    4. Urinary Tract Infection
    5. Infectious Enteritis
    6. Borrelia Burgdorferi (Lyme Disease)
    7. Helicobacter Pylori
  • Adverse effects
  1. Similar to Natural Penicillins
  2. Maculopapular rash
    1. Onset 5-7 days after initiating medication
    2. Typically not IgE mediated (non-allergic)
      1. No immediate allergy (e.g. Urticaria), systemic symptoms or mucous membrane involvement
    3. Typically safe to use Amoxicillin in future if non-allergic rash alone
      1. Consider IgE Skin Testing if unclear rash etiology
    4. References
      1. Orman and Hayes in Herbert (2017) EM:Rap 17(7): 7-8
  3. Diarrhea (modifications can decrease stools to 12%)
    1. Dose exactly by kilogram for children
    2. Avoid food before dose
    3. Consider eating yogurt with each dose