Neonatal Drug Therapy Manual


Disclaimer: Official controlled document is the CHEO and Ottawa Hospital online copy. It is the responsibility of user to ensure that any paper copy version is the same as the online version before use.

Alternate Name(s): 
Orbenin, Tegopen
Antibiotic (semi-synthetic penicillin)
Original Date: 
March 1993
Revised Date: 
September 2020
  • Treatment of infections caused by penicillinase-producing strains of Staphylococci
  • IV direct: over 5 - 10 minutes
  • IV intermittent infusion: over 15 - 30 minutes


< 2 kg:

  • 0 - 7 days: 25 mg/kg/dose Q12H
  • > 7 days: 25 mg/kg/dose Q8H

>  2 kg:

  • 0 - 7 days: 25 mg/kg/dose Q8H
  • > 7 days: 25 mg/kg/dose Q6H


For suspected meningitis, serious or invasive infections: 50 mg/kg/dose using appropriate dosing interval as above 

Side Effects: 
  • GI: diarrhea
  • Hematologic (rare): anemia, leukopenia, thrombocytopenia
  • Hepatic: elevated liver enzymes
  • Local: phlebitis
  • Renal: acute interstitial nephritis
Parameters to Monitor: 
  • CBC with differential
  • Liver function tests
  • BUN and serum creatinine
  • Injection site
Reconstitution and Stability: 

Cloxacillin 2 g vial

  • Add 18.7 mL SWFI
  • Take 4 mL (400 mg) and add to 16 mL D5W.
  • Final concentration: 20 mg/mL



- Solutions Compatible: dextrose, saline, dextrose-saline combinations

- Y-site Compatible: amino acids and dextrose, heparin, KCl (up to 60 mmol/L)

Incompatible: gentamicin, hydromorphone, lipids, pantoprazole, morphine


- In case of extravasation, hyaluronidase should be administered


- Cloxacillin CPhA monograph, Apr 23, 2020

- American Society on Health-System Pharmacists (ASHP). Handbook on Injectable Drugs 19th Edition. Bethesda: American Society of Health-System Pharmacists; 2017



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