Benzylpenicillin

Benzylpenicillin

Systematic (IUPAC) name
(2S,5R,6R)-3,3-dimethyl-7-oxo-6-(2-phenylacetamido)-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid
Clinical data
Trade names	BenPen
AHFS/Drugs.com	Micromedex Detailed Consumer Information
MedlinePlus	a685013
Pregnancy category	AU: A US: B (No risk in non-human studies)
Legal status	℞ (Prescription only)
Routes of administration	Intravenous, Intramuscular, formerly used orally
Pharmacokinetic data
Protein binding	60 %
Metabolism	hepatic
Biological half-life	30 min
Excretion	renal
Identifiers
CAS Number	61-33-6 Y (free acid) Template:CAS (sodium salt)
ATC code	J01CE01 (WHO) S01AA14 QJ51CE01 (WHO)
PubChem	CID: 5904
IUPHAR/BPS	4796
DrugBank	DB01053 Y
ChemSpider	5693 Y
UNII	Q42T66VG0C Y
KEGG	D02336 N
ChEBI	CHEBI:18208 N
ChEMBL	CHEMBL29 N
Chemical data
Formula	C16H18N2O4S
Molecular mass	334.4 g/mol
SMILES CC1([C@@H](N2[C@H](S1)[C@@H](C2=O)NC(=O)Cc3ccccc3)C(=O)O)C
InChI InChI=1S/C16H18N2O4S/c1-16(2)12(15(21)22)18-13(20)11(14(18)23-16)17-10(19)8-9-6-4-3-5-7-9/h3-7,11-12,14H,8H2,1-2H3,(H,17,19)(H,21,22)/t11-,12+,14-/m1/s1 Y Key:JGSARLDLIJGVTE-MBNYWOFBSA-N Y
NY (what is this?)  (verify)

2,400,000 units of Bicillin L-A brand of benzylpenicillin, for deep intramuscular injection

Benzylpenicillin (INN, AAN, BAN), also known as penicillin G, (USAN) is a narrow spectrum penicillin antibiotic that is given intravenously or intramuscularly as a treatment for syphilis, meningitis, endocarditis, pneumonia, lung abscesses and septicaemia in children. Penicillin G is typically given by injection parenterally, bypassing the intestines, because it is unstable in the highly acidic 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.

It is on the World Health Organization's List of Essential Medicines, a list of the most important medications needed in a basic health system.

Medical uses

Specific indications for benzylpenicillin include:

• Cellulitis
• Infective endocarditis
• Meningitis
• Aspiration pneumonia, lung abscess
• Community-acquired pneumonia
• Syphilis
• Septicemia in children
• Septic Arthritis
• Gangrene
• Diphtheria

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.

Adverse effects

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 person 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

• British Pharmacopoeia