• See Also
  1. Aminopenicillin
  2. Ampicillin
  3. Augmentin
  4. Unasyn
  • Indications
  1. Otitis Media
  2. Acute Bacterial Sinusitis
  3. Pneumonia
  4. Group A Streptococcal Pharyngitis
  5. Helicobacter Pylori
  6. Endocarditis Prophylaxis
  • Contraindications
  1. Penicillin Allergy
    1. Cefadroxil and Cefprozil have similar side chains and risk of cross reactivity with Amoxicillin
  • Mechanism
  1. See Aminopenicillin
  • Medications
  1. Amoxicillin Capsules (250 and 500 mg)
  2. Amoxicillin Tablets (500 and 875 mg)
  3. Amoxicillin Chewable Tablets (125, 200, 250 and 400 mg)
  4. Amoxicillin Suspension (125 mg/5ml and 250 mg/5ml)
    1. Stable in the refrigerator for up to 14 days
  • Dosing
  1. Adult
    1. Typical Dosing (e.g. head and neck infections): 875 to 1000 mg orally twice daily
    2. Maximum dose: 3-4 grams/day
  2. Child
    1. Low dose (e.g. Pneumonia): 45 mg/kg/day divided twice daily
    2. High dose (e.g. Otitis Media): 90 mg/kg/day divided twice daily
  3. Renal Dosing (adult dosing adjustments)
    1. eGFR 10 to 30 ml/min: 250 to 500 mg orally twice daily
    2. eGFR <10 ml/min: 250 to 500 mg orally daily (after Hemodialysis)
  • Adverse Effects
  1. See Aminopenicillin
  2. See Penicillin
  3. 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
  4. Diarrhea
    1. More common with Augmentin
    2. Modifications can decrease stools
      1. Dose exactly by kilogram for children
      2. Avoid food before dose
      3. Consider eating yogurt with each dose
  5. Drug-Induced Enterocolitis Syndrome (DIES)
    1. Non-IgE mediated Hypersensitivity Reaction resulting in severe Vomiting, Diarrhea
    2. Rare complication, primarily in children, and similar to Food Protein Induced Enterocolitis Syndrome (FPIES)
    3. Presents with repeated delayed Vomiting >1 hour after medication without rash or respiratory symptoms
    4. May be associated with lethargy, pallor, Diarrhea and Dehydration
    5. Unique features include Neutrophilia and Methemoglobinemia
    6. References
      1. (2024) Presc Lett 31(11): 64-5
      2. Di Filippo (2023) Int J Mol Sci 24(9):7880 +PMID: 37175584 [PubMed]
  • Safety
  1. Pregnancy Category B
  2. Safe in Lactation
  • Resources
  1. Amoxicillin Capsule (DailyMed)
    1. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=843f6053-63d9-47d2-81f1-b6aa78a7c20c
  • References
  1. (2008) Comparison of Amoxicillin Products, Presc Lett, #240425
  2. Hamilton (2020) Tarascon Pocket Pharmacopoeia
  3. Miller (2002) J Midwifery Womens Health 47(6):426-34 +PMID: 12484664 [PubMed]
  4. Bush (2016) Cold Spring Harb Perspect Med 6(8):a025247 +PMID: 27329032 [PubMed]