|Systematic (IUPAC) name|
|Pregnancy cat.||B (US)|
|Legal status||℞ Prescription only|
|Protein binding||60 %|
69-57-8 (sodium salt)
|ATC code||J01 S01 QJ51|
|Mol. mass||334.4 g/mol|
| (what is this?)
Benzylpenicillin, commonly known as penicillin G, is the gold standard type of penicillin. 'G' in the name 'Penicillin G' refers to 'Gold Standard'. Penicillin G is typically given by a parenteral route of administration (not orally) because it is unstable in the hydrochloric acid of the stomach. Because the drug is given parenterally, higher tissue concentrations of penicillin G can be achieved than is possible with phenoxymethylpenicillin. These higher concentrations translate to increased antibacterial activity.
Antimicrobial Potency 
As an antibiotic, Penicillin G is noted to possess effectiveness mainly against Gram-positive organisms. Some Gram-negative organisms such as Neisseria gonorrhoeae and Neisseria meningitidis are also reported to be susceptible to Penicillin G.
Medical uses 
Specific indications for benzylpenicillin include:
- Infective endocarditis
- Aspiration pneumonia, lung abscess
- Community-acquired pneumonia
- Septicemia in children
- Septic Arthritis
Adverse effects 
|This section does not cite any references or sources. (April 2011)|
Adverse effects can include hypersensitivity reactions including urticaria, fever, joint pains, rashes, angioedema, anaphylaxis, serum sickness-like reaction. Rarely CNS toxicity including convulsions (especially with high doses or in severe renal impairment), interstitial nephritis, haemolytic anaemia, leucopenia, thrombocytopenia, and coagulation disorders. Also reported diarrhoea (including antibiotic-associated colitis).
Benzylpenicillin serum concentrations can be monitored either by traditional microbiological assay or by more modern chromatographic techniques. Such measurements can be useful to avoid central nervous system toxicity in any patient receiving large doses of the drug on a chronic basis, but they are especially relevant to patients with renal failure, who may accumulate the drug due to reduced urinary excretion rates.
Compendial status 
|This section requires expansion. (March 2010)|
- "Penicillin G" (pdf). Toku-E. 2010-10-10. Retrieved 2012-06-11.
- Rossi S, editor, ed. (2006). Australian Medicines Handbook. Adelaide: Australian Medicines Handbook. ISBN 0-9757919-2-3.
- Fossieck B Jr, Parker RH. Neurotoxicity during intravenous infusion of penicillin. A review. J. Clin. Pharmacol. 14: 504- 512, 1974.
- R. Baselt, Disposition of Toxic Drugs and Chemicals in Man, 8th edition, Biomedical Publications, Foster City, CA, 2008, pp. 1195-1196.
- British Pharmacopoeia Commission Secretariat. "Index (BP 2009)". Retrieved 26 March 2010.