Reviewed by Dr Carl Kuschel, Dorothy Cooper
September 1998
Administration Newborn Drug Protocol Index Newborn Services Home Page

Dose and Administration

  1. 10-20 mg/kg/day PO nocte prophylaxis.
  2. 40 mg/kg/day as 3 divided doses as treatment


  1. Prophylaxis against urinary tract infections.
  2. Treatment e.g. otitis media.

Contraindications and Precautions

  1. Hypersensitivity to penicillin or cephalosporins.

Clinical Pharmacology

Semisynthetic second generation cephalosporin antibiotic for oral administration. Usually active against the following organisms: Staphylococci species, Streptococcus pyogenes, Streptococcus pneumoniae, Escherichia coli, Proteus spp, Klebsiella spp, Haemophilus influenzae (including most beta lactamase producing ampicillin resistant strains), Neisseria gonorrhoeae, and several anaerobic bacteria (excluding Bacteroides fragilis). Note that Pseudomonas spp and most strains of enterococci, enterobacter spp, indole positive proteus and serratia spp are resistant to cefaclor. Action results from inhibition of synthesis of cell wall mucopeptides.

Cefaclor is well absorbed after oral administration, whether taken with food or while fasting. However, when taken with food, the peak concentration is less and occurs later than that observed when the medicine is administered to fasting subjects. Widely distributed throughout body fluids and tissues. Does not penetrate the CSF. Approximately 60-85% of the drug is excreted unchanged in the urine. Elevated serum concentrations may be reduced by haemodialysis.

Possible Adverse Effects

  1. Rash, fever and urticaria.
  2. Gastrointestinal disturbances (nausea, vomiting, diarrhoea, candidiasis).
  3. Transient fluctuations in leucocyte count, eosinophilia, thrombocytopenia.
  4. False/positive Coomb's test, 40-75%.
  5. Transient slight elevations in AST, ALP, or serum creatinine.
  6. Stevens-Johnson Syndrome, toxic epidermal necrolysis.
  7. Hyperactivity, somnolence.
  8. False/positive urine glucose determination on Clinitest.


Chloramphenicol - antagonistic effect do not use together.

Special Considerations

  1. The safety and effectiveness of cefaclor for use in infants less than one month of age has not been established.
  2. False/positive reaction for glucose in the urine may occur with Clinitest tablets.
  3. Forced diuresis, peritoneal dialysis, haemodialysis or charcoal haemoperfusion have not been established as beneficial for an overdose of cefaclor.