Amoxil, Ibiamox

Reviewed by Brenda Hughes (pharmacist), Dr Lesley Voss (SCH I.D), Eamon Duffy (pharmacist/I.D)
August 2016
Administration Newborn Drug Protocol Index Newborn Services Home Page


Dose and Administration


Suspected Sepsis:11,12


Postnatal Age

Dosing Interval




0 to 7





>28days post term 6hrly
Refer to SSH Meningitis Guideline


  1. Empirical therapy for infants with risk factors for sepsis or suspected sepsis. Usually administered in combination with gentamicin, cefotaxime
  2. Specific therapy for Streptococcus agalactiae (Group B streptococcus), Listeria monocytogenes


  1. Hypersensitivity to penicillins/cephalosporins.

Precautions 11

  1. Caution in preterm infants, especially extreme immaturity.
  2. Caution in infants with renal impairment – reduce dose
  3. Caution in infants with gastrointestinal disease.

Clinical Pharmacology

Amoxicillin is a broad spectrum penicillin with antibacterial activity against certain gram negative and gram positive organisms.  It is in activated by penicillinases including those produced by Staphylococcus aureus, E.coli, Pseudomonas, Klebsiella, and Enterobacter.6

Widely distributed at varying concentrations in human body tissues and fluids.  Very little passes into the CSF unless the meninges are inflamed.  Low binding to human plasma protein.  Half-life (adults) of 1 to 1.5 hours, which would be extended in the neonate. 7   Excreted mainly unchanged by the kidneys.

Possible Adverse Effects11,12

  1. Venous irritation, soft tissue injury at site of IV injection.
  2. Crystalluria – may be associated with reduced urine output
  3. Gastrointestinal disturbance (diarrhoea
  4. Hypersensitivity reactions (including urticaria, fever, joint pains, rash, angioedema, anaphylaxis, serum sickness-like reaction (discontinue treatment).
  5. CNS toxicity including convulsions (with high doses or in severe renal impairment)

Special Considerations11,12,13

  1. May give concurrently with aminoglycoside therapy for synergistic effect.
  2. Administer amoxicillin separately from aminoglycosides as simultaneous administration may cause inactivation.
  3. Maintain adequate fluid intake and urinary output during administration of high doses, to avoid crystalluria.