Some organisms are penicillin-resistant because they produce an enzyme
called penicillinase, that destroys the antibiotic. Oxacillin, derived from
6-aminopenicillanic acid, is a semisynthetic penicillinase-resistant penicillin
against staphylococci primarily. New penicillins such as methicillin, (di)cloxacillin,
flucloxacillin
and
oxacillin are not destroyed by the penicillinase, but have no effect on bacteria
that are resistant by other means like by altered cell wall structure. Macrolide
antibiotics that inhibits protein synthesis by bacteria have become important in
treating penicillin-resistant infections in patients allergic to penicillin. The
sodium salt of oxacillin is administered orally, intramuscularly, or
intravenously. Chemical designation is [2S (2a, 5a,
6b)]-3.3-dimethyl-6-[[(5-methyl-3-phenyl-4-isoxazolyl) carbonyl]
amino]-7-oxo-4-thia-1- azabicyclo [3.2.0]heptane-2-carboxylic acid, monosodium
salt. |
· Penicillin: Any of a large group of broad-spectrum antibiotic drugs derived
directly or indirectly from molds of the genus Penicillium and other
soil-inhabiting fungi grown on special culture media, which exert a
bacteriocidal as well as a bacteriostatic effect on susceptible bacteria during
their growth stage by the inhibition of biosynthesis of their cell wall
mucopeptide. Penicillin, beta-lactam antibiotics, possess a four-ring
beta-lactam structure shares a nitrogen and a carbon atom with fused a
five-membered thiazolidine ring. These antibiotics have low toxicity for the
host but effective against most gram-positive bacteria including pathogens
(streptococci, staphylococci, pneumococci); clostridia; some gram-negative
gonococci; some spirochetes (Treponema pallidum and T. pertenue); and some
fungi. Certain strains of some target species, e.g., staphylococci, secrete the
enzyme penicillinase, which inactivates penicillin and confers resistance to the
antibiotic.
·
Penicillic acid [CAS RN: 90-65-3]: an antibiotic substance
produced by several species of Penicillium and Aspergillus; a white solid
soluble in water; melting point 83 - 84 C; antibiotic and mycotoxin induceing
DNA single-strand breaks, toxic to animal tissues also, causing nephrotoxicity
and other damage.
·
Penicillin G [also called benzylpenicillin, CAS RN:
61-33-6]: the first and the most widely used penicillin compound for medicinal
use. It is used in the form of its stable salts (benzathine, potassium,
procaine, and sodium) to treat principally the infections due to
penicillin-susceptible gram-positive bacteria, gram-negative cocci, Treponema
pallidum, and Actinomyces israelii.
·
Penicillin G Benzathine [CAS RN: 41372-02-5]: the benzathine
salt of penicillin G; having a long-sustained action, administered orally,
intramuscularly. Chemically designation is (2S,5R,6R)- 3,3-Dimethyl-7-oxo-6-(2-phenylacetamido)-4-thia-1-azabicyclo [3.2.0] heptane-2-carboxylic acid
with N,N' -Dibenzylethylenediamine (2:1). It is a white crystalline powder;
slightly soluble in water
and sparingly soluble in alcohol.
·
Penicillin G Potassium [CAS RN: 113-98-4]: the potassium salt
of penicillin G; administered orally and by intravenously. It is a white crystalline
powder; odorless, moderately hygroscopic; soluble in water.
·
Penicillin G
Procaine [CAS RN: 6130-64-9]: the procaine salt of penicillin G; having a long-sustained
action, administered intramuscularly. Chemically designation is (2S,5R,6R)-
3,3-Dimethyl-7-oxo-6-(2-phenylacetamido)-4-thia-1-azabicyclo [3.2.0] heptane-2-carboxylic acid with 2-(Diethylamino)ethyl p-aminobenzoate (1:1).
It is a white crystalline powder; slightly soluble in water.
·
Penicillin G sodium [CAS RN: 69-57-8]: the sodium salt of
penicillin G having a potency of 1500–1750 U per mg; administered
intramuscularly and intravenously.
·
Penicillin N (also called adicillin, CAS
RN: 525-94-0]: a cephalosporin that is more active against gram-negative
organisms than penicillin G and is highly active against Neisseria; has been
used in the treatment of typhoid fever and gonorrhea.
·
Penicillin O: similar
to penicillin G in antibiotic action but produced by adding a precursor to the
culture medium; penicillin O and its potassium and sodium salts are
hypoallergenic.
·
Penicillin V: [CAS RN: 87-08-1] a semisynthetic penicillin
prepared from cultures of the mold Penicillium in the presence of
2-phenoxyethanol with an autolysate of yeast as the source of nitrogen; a white,
crystalline powder, soluble in alcohol and acetone; resists destruction by high
humidity (gastric juice), thus orally effective.
·
Penicillin V Benzathine [CAS RN: 63690-57-3] : the benzathine salt of penicillin V, administered orally.
Chemical designation is [2S-(2a,5a,6b)]-3,3
-dimethyl-7-oxo-6-[(phenoxyacetyl)amino]-4- thia-1- azabicyclo[3.2.0] heptane-2-carboxylic
acid with N,N' -Dibenzylethylenediamine (2:1).
·
Penicillin V
Potassium [CAS RN: 132-98-9]: the potassium salt of penicillin V,
administered orally. Chemical designation is [2S-(2a,5a,6b)]-3,3
-dimethyl-7-oxo-6-[(phenoxyacetyl)amino]-4- thia-1- azabicyclo[3.2.0] heptane-2-carboxylic
acid, monopotassium salt. |