Cep Halos Por Ines

8/18/2019 Cep Halos Por Ines

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These are the second major group of Beta-lactam, broad spectrum penicillinase

resistance antibiotics derived from the microoraganism Acrimonium chrysogenum.It was

previously known as Cephalosporium’’.It was found in a sewage outfall off the !ardinian

coast in "#$% by Italian scientist &iuseppe Brot'u. (ephalothin )cefalotin* ,the first agent was

launched by +li illy in "#$.

MODE OF ACTION

(ephalosporins are bactericidal agents and have the same mode of action as other beta-

lactam antibiotics.The cell wall protects the all bacterial cells. (ephalosporins interrupt the

synthesis of the peptidoglycan layer of bacterial cell walls, which causes the walls to break

down and finally the bacterial death. eptidoglycan is a heteropolymeric component and it

provides rigid mechanical stability of the cell wall.The last transpeptidation step in the

synthesis of the peptidoglycan is facilitated by transpeptidases known as penicillin binding

protein.These proteins bind to the /-Ala-/-Ala at the end of muropeptides )peptidoglycan

precursors* to crosslink the peptidoglycan. (ephalosporins mainly mimic the structure of the

/-Ala-/-Ala link and disrupting the cross-linking process. If the peptidoglycan fails to

cross-link the cell wall it loose the strength of the wall and cell lysis occurs.

CLASSIFICATION OF CEPHALOSPORIN

They are grouped into generations based mainly on their spectrum of antimicrobial

activity. 0ewer generation of cephalosporins has significantly greater gram-negative

antimicrobial spectrum than the previous one, and decreased activity against gram-positive

organisms. The newer generations have much longer half-lives resulting in the decrease of

dosing fre1uency. 2ourth generation cephalosporins have true broad spectrum activity.

FIRST GENERATION

Cephalexin, po

Cefazolin

Cephalothin

Cephradine, po


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It mainl a!t" on #ram po"iti$e %a!teria&

'SES

3pper respiratory tract infections due to !taphylococcus and !treptococcus, ower

respiratory tract infections due to susceptible bacteria e.g. !trep. neumonia in penicillin-

allergic patient )previous rash,. 3ncomplicated urinary tract infections )(ephale4in*, surgical

prophyla4is for orthopedic and cardiovascular operations )cefa'olin preferred because of

longer half-life*, !taphylococcal infections of skin and skin structure

2+AT35+!

6They have relatively short half- lives. oor ability to penetrate into cerebrospinal fluid

6They have narrow spectrum of antibacterial activity.

6They are resistant to 7- lactamase produced by &r 8ve bacteria only.

Spe!tr(m of a!ti$it)

&ood coverage on gram positive cocci 9 Streptococci, Staphylococci, Enterococci.

0:T effective against methicillin-resistant Staph. aureus, penicillin-resistant Strep.

pneumoniae.

;odest coverage on gram negative cocci9 Escherichia coli, Proteus mirabilis, and Klebsiella

pneumoniae, though susceptibilities may vary. oor activity against Moraxella

catarrhalis and Hemophilus influenzae.

Active against most of the penicillin-susceptible anaerobes that are found in the oral cavity,

e4cept Bacteroides frailis group.

;ost commonly used "st generation cephalosporin is (efa'olin.It had increased risk of

cross-reactivity in penicillin-allergic patients in comparison with other cephalosporins .

!+(:0/ &+0+5ATI:0

*Tr(e* "e!ond #eneration in!l(de")

•

cefpro'il )(ef'il*


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• cefuro4ime )(eftin,


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&ram-positive cocci9 articularly agents available in an oral formulation have limited activity

against gram-positive cocci. (efota4ime and ceftria4one have increased potency against

penicillin-resistant pneumococci compared with first- and second-generation agents. But

(efi4ime and (eftibuten lack Staphylococcus activity.

'"e")

3pper respiratory tract infections

:titis media

&ram-negative bacillary meningitis

!erious infections of +nterobacteriaceae

yelonephrits

!kin and soft tissue infections

yme disease and gonorrhoea-(eftria4one

enetration into the cerebrospinal fluid-(efota4ime, cefta'idime, ceftria4one,

cefti'o4ime, and mo4alactam

(ephalosporins are not the drugs of choice for +nterobacter infections, because they

have a tendency to become resistant during cephalosporin therapy.

AntiP"e(domonal Cephalo"porin"

(efta'idime )2orta', Ta'icef, Ta'idime* and (efopera'one )(efobid* are the two third

generation cephalosporins with antipseudomonal activity.

Spe!tr(m of a!ti$it) ;ain indication is Pseudomonas aeruinosa

2:35T> &+0+5ATI:0

It has the broadest spectrum of activity. (urrently available fourth generation

cephalosporin is cefepime. They have similar activity against gram-positive organisms as first

generation cephalosporins and have a greater resistance to beta-lactamases than the third

generation cephalosporins. It includes cefepimcefluprenam, cefo'opran, cefpirome,

cef1uinome.


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Spe!tr(m of a!ti$it)

Broad coverage of gram positive and gram negative organisms. &ram-positive cocci

like Streptococcus pneumoniae, &roups A and B streptococci, methicillin-

susceptible Staphylococcus aureus )less potent than the "st and nd generation agents* and

&ram-negative bacteria like +nterobacteriaceae and seudomonas aeruginosa.They had

increased activity compared to Crd generation. But minimal anaerobic coverage.

'"e")

>ighly active against nosocomial pathogens sand are primary used for nosocomial infections-

(efepime and cefpirome.They can cross blood-brain barrier and can be used in the treatment

of meningitis.

2I2T> &+0+5ATI:0

They have similar gram negative coverage to third- and fourth-generation agents and

enhanced coverage of gram positive organisms9 ;5!A, !. pneumonia, and +. faecalis .But

anaerobic activity is limited.It includes drugs like ceftaroline fosamil ,ceftobiprole .

!I/+ +22+(T!

&I system-/iarrhoea, nausea, mild stomach cramps or upset

Allergic reactions9 anaphyla4is )rare*, rash )maculopapular, urticarial*, serum sickness-like

reaction, eosinophilia, interstitial nephritis.

:ther side effects are black, tarry stools painful or difficult urination antibiotic-induced

colitis )severe watery diarrhea, severe stomach cramps, fever, and weakness*.

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