3. Cephalosporins were first introduced in the
1960s.
There are currently four generations of
Cephalosporins, each with specific spectrum of
activity.
These drugs are similar to penicillins in
structure and activity.
CEPHALOSPORINS
3/31/2021 Z.M.NATHANI 3
5. 1. First generation Cephalosporin
1. Cephalexin
2. Cephradine
3. Cephalothin
4. Cefadroxil
5. Cefuzolin: drug of choice for surgical
prophylaxis
6. Cephapirin
3/31/2021 Z.M.NATHANI 5
6. 3/31/2021 Z.M.NATHANI 6
1. 1st generation cephalosporin have broad spectrum of activity
and low toxicity.
2. 1st generation cephalosporin are very active against gram +ve
cocci such as Pneumococci, viridans streptococci, β-hemolytic
streptococci and staphylococci.
3. They are effective against gram –ve rods such as coli,
Klebseilla pneumoniae, proteus mirabilis but have very little
activity against Pseudomonas aerogenosa, Proteus vulgaris,
Enterobacter, Citrobacter, Serratia and Acinetobacter.
4. They are also active against anaerobes
like Peptococcus and Streptococcus but ineffective
against Bacteroids fragillis.
5. None of the 1st generation cephalosporin can cross brain
barrier. Therefore they cannot be used for treatment of
meningitis.
8. 3/31/2021 Z.M.NATHANI 8
2nd generation cephalosporin have extended gram-ve
coverage than that of 1st generation cephalosporin.
They are heterogenous groups of antibiotics with different
antimicrobial activity.
They are active against Enterobacter, Proteus vulgaris,
Klebsiella, H. influenzae
10. 3/31/2021 Z.M.NATHANI 10
** All 3rd generation cephalosporin except cefoperazone and
cefixime can cross blood brain barrier and therefore can be used
to treat meningitis.
1. 3rd generation cephalosporin have extended spectrum of
activities and they have extended gram –ve coverage.
2. Including Citrobacter, Enterobacter, Provedeneia,
Pseudomonas aerogenosa and β-lactamase producing
meningococci and H. influenzae.
3. This generation cephalosporin are usually used in treatment
of sepsis of unknown origin especially in
immunocompromised patients in in those individuals where
cephalosporin possess least toxicity.
11. 3/31/2021 Z.M.NATHANI 11
4. Fourth generation Cephalosporin
Cefepime
Cefpirome
A. 4th generation cephalosporin have extended
gram –ve coverage and they have increased
activity against Streptococci and MRSA.
B. The activity of 4th generation cephalosporin
can be comparable to Ceftazime
against Pseudomonas.
12. 3/31/2021 Z.M.NATHANI 12
5. Fifth generation Cephalosporin
Ceftaroline
Ceftabiprole
They are extended cephalosporin with
extended spectrum of activities against
MRSA
13. 1. Exert bactericidal and bacteriostatic
effects by interfering with the cell-wall
building ability of bacteria during cell
division.
2. Therefore, they prevent the bacteria from
bio synthesizing the framework of their
cell walls.
Therapeutic Action
3/31/2021 Z.M.NATHANI 13
15. 3/31/2021 Z.M.NATHANI 15
1. Many of the cephalosporin
eg. Cephalexin, cefotaxime and ceftazidime binds
to Penicillin binding protein 3 (PBP3) similar to
action of penicillin and results in formation of
elongated and filamentous cell.
2. Transpeptidase is the enzyme present in bacteria
that cross linked with existing peptidoglycan chain
and maintain integrity of cell wall.
3. Binding of cephalosporin on PBP3 receptor
deforms cell wall and kills bacteria.
BINDS TO PENICILLIN
BINDING PROTEIN (PBP)
16. 3/31/2021 Z.M.NATHANI 16
Activation of autolysin
Cephalosporin also activates
autolytic enzymes in bacteria and
causes lysis of bacteria
ACTIVATION OF AUTOLYSIN
17. 1. First-generation cephalosporins are effective against the same gram-
positive bacteria affected by penicillin G, as well as gram-negative
bacteria P.mirabilis, K.pneumoniae, E.coli.
2. Second-generation cephalosporins are effective against previously
mentioned strains as well as H.influenzae, E.aerogenes, and Neisseria
spp. These drugs are less effective against gram-positive bacteria.
3. Third-generation Cephalosporins are effective against all of the
previously mentioned strains. They are relatively weak against gram-
positive bacteria but are more potent against gram-negative bacilli, as
well as S.marcescens.
4. Fourth-generation cephalosporins are active against gram-negative and
gram-positive organisms, including cephalosporin-resistant
staphylococci and P.aeruginosa.
INDICATIONS
3/31/2021 Z.M.NATHANI 17
18. Here are the characteristic interactions of
cephalosporins and the body in terms of absorption,
distribution, metabolism, and excretion.
PHARMACOKINETICS
3/31/2021 Z.M.NATHANI 18
Route Onset Peak Duration
Oral N/A 30-60 min 8-10 h
T1/2: 30-60 min
Metabolism: N/A
Excretion: kidney (urine); unchanged
19. 1. Known allergy to cephalosporins and bea-lacams. Cross-reacions
are common.
2. Hepatic or renal impairment. These drugs are toxic to the kidneys
and could interfere with the metabolism and excretion of the drugs.
3. Pregnancy and lactation. Potential effects on the fetus and infant are
not known; use only if benefits clearly outweigh the potential risk of
toxicity to the fetus or infant.
4. Reserve cephalosporins for appropriate situations because
cephalosporin-resisant bacteria are appearing in increasing numbers.
Perform culture and sensitivity test before start of therapy.
CONTRAINDICATIONS AND
CAUTIONS
3/31/2021 Z.M.NATHANI 19
21. CNS
1. Headache.
2. Dizziness.
3. Lethargy.
4. Paresthesias.
Superinfectons
Phlebitis and local abscess at the site of IM
injection and/or IV administration.
3/31/2021 Z.M.NATHANI 21
22. 3/31/2021 Z.M.NATHANI 22
The following are drug-drug interactions involved in the use of
cephalosporins
1. Aminoglycosides: increased risk for nephrotoxicity.
2. Oral anticoagulants: increased bleeding.
3. Alcohol: avoided for 72 hours after discontinuation of the
drug to prevent disulfiram-like reaction (e.g. flushing,
throbbing headache, nausea and vomiting, chest pain,
palpitations, dyspnea, syncope, vertigo,
convulsions, etc.)
INTERACTIONS
