Carbenicillin is a

bactericidal A bactericide or bacteriocide, sometimes abbreviated Bcidal, is a substance which kills bacteria. Bactericides are disinfectants, antiseptics, or antibiotics. However, material surfaces can also have bactericidal properties based solely on their ...

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...

belonging to the

carboxypenicillin The carboxypenicillins are a group of antibiotics. They belong to the penicillin family and comprise the members carbenicillin and ticarcillin. Chemical structure The carboxypenicillins feature the beta-lactam backbone of all penicillins b ...

subgroup of the

penicillin Penicillins (P, PCN or PEN) are a group of β-lactam antibiotics originally obtained from ''Penicillium'' moulds, principally '' P. chrysogenum'' and '' P. rubens''. Most penicillins in clinical use are synthesised by P. chrysogenum using ...

s. It was discovered by scientists at

Beecham Beecham is a surname. Notable people with the surname include: * Audrey Beecham (1915–1989), poet and niece of the conductor * Betty Humby Beecham (1908–1958), British pianist and wife of the conductor * Earl Beecham (born 1965), American foo ...

and marketed as Pyopen. It has

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...

coverage which includes ''

Pseudomonas aeruginosa ''Pseudomonas aeruginosa'' is a common encapsulated, gram-negative, aerobic–facultatively anaerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, ''P. aerugi ...

'' but limited

Gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacte ...

coverage. The carboxypenicillins are susceptible to degradation by

beta-lactamase Beta-lactamases, (β-lactamases) are enzymes () produced by bacteria that provide multi-resistance to beta-lactam antibiotics such as penicillins, cephalosporins, cephamycins, monobactams and carbapenems (ertapenem), although carbapenems ...

enzymes, although they are more resistant than

ampicillin Ampicillin is an antibiotic used to prevent and treat a number of bacterial infections, such as respiratory tract infections, urinary tract infections, meningitis, salmonellosis, and endocarditis. It may also be used to prevent group B strepto ...

to degradation. Carbenicillin is also more stable at lower pH than ampicillin.

Pharmacology

The antibiotic is highly soluble in water and is acid-labile. A typical lab working concentration is 50 to 100 µg per ml. It is a semi-synthetic analogue of the naturally occurring benzyl-penicillin. Carbenicillin at high doses can cause bleeding. Use of carbenicillin can cause

hypokalemia Hypokalemia is a low level of potassium (K+) in the blood serum. Mild low potassium does not typically cause symptoms. Symptoms may include feeling tired, leg cramps, weakness, and constipation. Low potassium also increases the risk of an abno ...

by promoting

potassium Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosphe ...

loss at the

distal convoluted tubule The distal convoluted tubule (DCT) is a portion of kidney nephron between the loop of Henle and the collecting tubule. Physiology It is partly responsible for the regulation of potassium, sodium, calcium, and pH. On its apical surface (lumen ...

of the kidney. In

molecular biology Molecular biology is the branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. The study of chemical and physi ...

, carbenicillin may be preferred as a selecting agent (see

Plasmid stabilisation technology A toxin-antitoxin system is a set of two or more closely linked genes that together encode both a "toxin" protein and a corresponding "antitoxin". Toxin-antitoxin systems are widely distributed in prokaryotes, and organisms often have them in mult ...

) because its breakdown results in byproducts with a lower toxicity than analogous antibiotics like

. Carbenicillin is more stable than ampicillin and results in fewer satellite colonies on selection plates. However, in most situations this is not a significant problem so

is sometimes used due to its lower cost.

Spectrum of bacterial susceptibility and resistance

Carbenicillin has been shown to be effective against bacteria responsible for causing urinary tract infections including ''Pseudomonas aeruginosa, Escherichia coli'', and some ''Proteus'' species. The following represents carbenicillin susceptibility data for a few medically significant organisms. This is not representative of all species of bacteria susceptible to carbenicillin exposure. * ''Escherichia coli'' 1.56 μg/ml - 64 μg/ml * ''Proteus mirabilis'' 1.56 μg/ml - 3.13 μg/ml * ''Pseudomonas aeruginosa'' 3.13 μg/ml - >1024 μg/ml http://www.toku-e.com/Assets/MIC/Carbenicillin%20disodium%20USP.pdf

References

{{PenicillinAntiBiotics Penicillins Phenyl compounds

Pharmacology

Spectrum of bacterial susceptibility and resistance

Further reading

References