Benzylpenicillin (Penicillin G)

Please note: This is for information only.

Refer to local guidelines for treatment recommendations



  • A penicillin
  • Usual adult dose 1.2 g IV QDS increasing to 1.2 g 4-hourly for streptococcal endocarditis or 2.4 g QDS for meningococcal sepsis
  • Dosage reduction necessary if renal impairment
  • Available IV only.
  • Crosses CSF only if meninges inflamed.

Main indications

  • Community acquired pneumonia
  • Cellulitis
  • Streptococcal endocarditis
  • Other serious streptococcal infections

Active against most strains of:

  • Streptococci (Group A, B, C, G, viridans, pneumoniae, milleri)
  • Neisseria meningitidis
  • Neisseria gonorrhoea - although many strains have low level resistance
  • Clostridium difficile
  • Clostridium perfringens

Not active against most strains of:

  • Staphylococci
  • Coliforms
  • Haemophilus influenzae
  • Pseudomonas
  • Bacteroides fragilis