Product Information

Registration Status: Active

PENICILLIN G SODIUM CRYST FOR INJECTION 5 MIL IU/VIAL is approved to be sold in Singapore with effective from 1988-04-05. It is marketed by NOVARTIS (SINGAPORE) PTE LTD, with the registration number of SIN00682P.

This product contains Benzylpenicillin 5 mil iu/vial in the form of INJECTION, POWDER, FOR SOLUTION. It is approved for INTRAVENOUS, INTRAMUSCULAR use.

This product is manufactured by SANDOZ GMBH in AUSTRIA.

It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.



Benzylpenicillin (Penicillin G) is narrow spectrum antibiotic used to treat infections caused by susceptible bacteria. It is a natural penicillin antibiotic that is administered intravenously or intramuscularly due to poor oral absorption. Penicillin G may also be used in some cases as prophylaxis against susceptible organisms. Natural penicillins are considered the drugs of choice for several infections caused by susceptible gram positive aerobic organisms, such as *Streptococcus pneumoniae*, groups A, B, C and G streptococci, nonenterococcal group D streptococci, viridans group streptococci, and non-penicillinase producing staphylococcus. Aminoglycosides may be added for synergy against group B streptococcus (*S. agalactiae*), *S. viridans*, and *Enterococcus faecalis*. The natural penicillins may also be used as first or second line agents against susceptible gram positive aerobic bacilli such as *Bacillus anthracis*, *Corynebacterium diphtheriae*, and *Erysipelothrix rhusiopathiae*. Natural penicillins have limited activity against gram negative organisms; however, they may be used in some cases to treat infections caused by *Neisseria meningitidis* and *Pasteurella*. They are not generally used to treat anaerobic infections. Resistance patterns, susceptibility and treatment guidelines vary across regions.


For use in the treatment of severe infections caused by penicillin G-susceptible microorganisms when rapid and high penicillin levels are required such as in the treatment of septicemia, meningitis, pericarditis, endocarditis and severe pneumonia.

Mechanism of Action

By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, penicillin G inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins; it is possible that penicillin G interferes with an autolysin inhibitor.


Rapidly absorbed following both intramuscular and subcutaneous injection. Initial blood levels following parenteral administration are high but transient. Oral absorption in fasting, healthy humans is only about 15-30% as it is very susceptible to acid-catalyzed hydrolysis.
0.53–0.67 L/kg in adults with normal renal function
About 16-30% of an intramuscular dose is metabolized to penicilloic acid, an inactive metabolite. Small amounts of 6-aminopenicillanic acid have been recovered in the urine of patients on penicillin G. A small percentage of the drug appears to be hydroxylated into one or more active metabolites, which are also excreted via urine.


560ml/min in healthy humans


Oral LD50 in rat is 8900 mg/kg [MSDS]. Neurological adverse reactions, including convulsions, may occur with the attainment of high CSF levels of beta-lactams. Neutropenia can occur if high doses are administered consistently for over 2 weeks.

Active Ingredient/Synonyms

(2S,5R,6R)-3,3-dimethyl-7-oxo-6-(phenylacetamido)-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid | 6-(2-phenylacetamido)penicillanic acid | Bencilpenicilina | bensylpenicillin | benzyl benicillin | Benzylpénicilline | Benzylpenicillinic acid | Benzylpenicillinum | Free penicillin II | PCG | Penicillin G | PG | Benzylpenicillin |

Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.


  1. Health Science Authority of Singapore - Reclassified POM
  2. Drugbank