Benzyl penicillin

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Structural formula
Structure of benzylpenicilin
General
Non-proprietary name Benzyl penicillin
other names
  • (2 S , 5 R , 6 R ) -3,3-Dimethyl-7-oxo-6- (2-phenylacetamido) -4-thia-1-azabicyclo [3.2.0] heptane-2-carboxylic acid ( IUPAC )
  • Penicillin G
  • Penicillin II
Molecular formula C 16 H 18 N 2 O 4 S
External identifiers / databases
CAS number 61-33-6
EC number 200-506-3
ECHA InfoCard 100,000,461
PubChem 5904
ChemSpider 5693
DrugBank DB01053
Wikidata Q258450
Drug information
ATC code

J01 CE01

Drug class

β-lactam antibiotic

properties
Molar mass 334.39 g · mol -1
Physical state

firmly

Melting point

217 ° C

pK s value

2.74 (25 ° C)

solubility

Water: 210 mg l −1 (25 ° C)

safety instructions
Please note the exemption from the labeling requirement for drugs, medical devices, cosmetics, food and animal feed
GHS labeling of hazardous substances
07 - Warning

Caution

H and P phrases H: 317
P: 280
Toxicological data

329 mg kg −1 ( LD 50 ,  mouse ,  iv )

As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Penicillin G (also called benzylpenicillin ) is a substance produced by the mold Penicillium notatum with an antibiotic effect and was discovered by Alexander Fleming in 1928 . Even today, benzylpenicillin is not produced synthetically, but obtained by fermentation from fungal cultures. Structurally, it is a β-lactam antibiotic .

Forms of trade

Penicillin G is the “parent substance” of penicillins , based on which derivatives with modified properties were developed. Its oral ineffectiveness due to acid instability and its sensitivity to the bacterial enzyme penicillinase are disadvantageous . Penicillin G can therefore only parenterally be administered, wherein the readily water-soluble potassium - or sodium salt for the intravenous or the sparingly water-soluble deposit penicillins benzylpenicillin benzathine or benzylpenicillin procaine come for intramuscular injection are used.

Spectrum of activity

The spectrum of activity comprises in broad terms:

The following pathogens are sensitive to penicillin G:

It should be noted that the number of penicillin G-resistant strains continues to increase, especially the gonococci .

Pharmacokinetics

Penicillin G is not acid-stable and can therefore be hydrolyzed by stomach acid . A parenteral , usually intravenous or intramuscular administration is therefore necessary. The release from intramuscular depot penicillins takes place slowly, with continuous plasma levels . In the case of intravenous administration (e.g. by means of a short infusion over 30-60 min), higher effective levels are achieved, but for an effective therapy with beta-lactam antibiotics, it is not the absolute concentration, but the time in which the effective levels are above the crucial minimal inhibitory concentration (MIC) of the pathogen. The plasma protein binding is approx. 50%, the elimination half-life is 30 to 40 minutes. Over 90% is excreted via the kidneys . In the case of intravenous administration, 50 to 70% of the dose is eliminated renally in an antibacterially active form, a further 20% in the form of inactive decay products, of which penicilloic acid forms the main part.

In meningitis , the CSF level reaches up to 50% of the plasma level, drops drastically after the infection has subsided (and thus the blood-brain barrier is intact again ). Therapeutic concentrations are achieved in the fetal circulation and in the amniotic fluid. In the breast milk 2-15% of the plasma concentration can be detected.

Penicillin G (as well as all other β-lactam antibiotics ) cannot achieve adequate antibacterial concentrations within the cells, which is why this group of substances cannot detect intracellular pathogens.

Indications

Against penicillin-sensitive pathogens, Penicillin G has the highest effectiveness of all penicillin antibiotics. Penicillin G is the agent of choice, especially for beta-hemolytic streptococci of group A or B and alpha-hemolytic streptococci of the Viridans group. Examples of conditions that are treated with penicillin G are:

Many diseases caused by pathogens sensitive to penicillin G are nevertheless treated with other antibiotics in everyday clinical practice. The reason for this are frequent mixed infections, in which several pathogens trigger the disease. Sepsis, meningitis and pneumonia are treated with broad-spectrum antibiotics even if there is evidence of primarily penicillin G-sensitive pathogens. The gonorrhea is now primarily a resistance to penicillin, because for many years due to sex tourism penicillin-resistant strains are introduced. An antibiogram is essential.
Due to the more conscious handling of antibiotics as part of antibiotic stewardship , after pathogen detection, in particular, the switch is made to antibiotics with a narrow spectrum of activity, such as penicillin G. As a result, penicillin G has been used increasingly again in recent years.

Stability of prepared solutions

The physico-chemical shelf life of a prepared aqueous solution is up to 8 hours at room temperature. The solutions are stable for up to 7 days when refrigerated (2–8 ° C). Frozen benzylpenicillin solutions (pH buffered at pH 6.85) with a concentration of 1-10% show less than 1% loss of activity after one month.

Trade names

Monopreparations

Penicillin G InfectoPharm 1/5/10 Mega (D), Penicillin G sodium (A)

Combination preparations

Tardocillin (D), Pendysin (D), Fortepen (A), Ophcillin (A), Retarpen compositum (A)

Veterinary medicine
  • Benzylpenicillin-Benethamine: Benestermycin (combination preparation with Neomycin, Framycetin)
  • Benzylpenicillin-Benzathine: Penomycin, Strepdipen, Veracin-compositum (combination preparations with Dihydrostreptomycin)
  • Benzylpenicillin potassium: Aviapen, Masticillin, Mastipen comp. (Station wagon), Mastitar forte (station wagon)
  • Benzylpenicillin Sodium: Penicillin G Sodium
  • Benzylpenicillin-Procain: Mastipen comp., Mastitar forte (Kombi), Medi-Proc, Nafpenzal T (Kombi), Neopen (Kombi), Penicillin-Dihydrostreptomycin-Suspension (Kombi), Penomycin (Kombi), Pro Pen, Procain-Penicillin, Procapen, Procillin, Procmast, Streptocombin (Kombi), Veracin-compositum (Kombi), Vetriproc, Veyxid Pen-Proc

literature

  • Aktories, Förstermann, Hofmann, Starke: General and special pharmacology and toxicology . 9th edition. 2005, ISBN 3-437-42521-8
  • Karow, Lang-Roth: General and Special Pharmacology and Toxicology 13th edition 2005

Individual evidence

  1. ^ J. Zhao, DM Lubman: Detection of liquid injection using an atmospheric pressure ionization radiofrequency plasma source. In: Analytical chemistry. Volume 65, Number 7, April 1993, pp. 866-876, PMID 8470818 .
  2. ↑ a b c Entry on benzylpenicillin in the ChemIDplus database of the United States National Library of Medicine (NLM)
  3. ↑ a b Data sheet Penicillin G potassium salt from Sigma-Aldrich , accessed on March 13, 2011 ( PDF ).
  4. ↑ External identifiers or database links for penicillin G potassium salt : CAS number: 113-98-4, EC number: 204-038-0, ECHA InfoCard: 100.003.671 , PubChem : 23664709 , ChemSpider : 391379 , DrugBank : DB01053 , Wikidata : Q27089370 .
  5. ↑ External identifiers or database links for penicillin G sodium salt : CAS number: 69-57-8, EC number: 200-710-2, ECHA InfoCard: 100.000.646 , PubChem : 23668834 , ChemSpider : 6014 , Wikidata : Q27122736 .
  6. ↑ Entry on benzylpenicillin. In: Römpp Online . Georg Thieme Verlag, accessed on July 25, 2012.
  7. ↑ External identifiers or database links for penicillin G procaine : CAS number: 54-35-3, EC number: 200-205-7, ECHA InfoCard: 100.000.187 , PubChem : 5903 , ChemSpider : 5692 , DrugBank : DB009320 , Wikidata : Q3435660 .
  8. ^ Burgis: Intensive General Course and spec. Pharmacology, 4th ed.
  9. ↑ a b c Technical information Penicillin G InfectoPharm.
  10. ↑ Hof, Dörries: Medical Microbiology, 3rd ed.
  11. ↑ a b Handbook on Injectable Drugs, 16th edition, as of October 2010.
  12. ↑ a b Red List Online, as of February 2016.
  13. ↑ Swiss Medicines Compendium , as of August 2009
  14. ↑ AGES-PharmMed, as of August 2009.