by student in o6u pharmacy(ahmed abo elkhair)

2. Content
• Introduction and Definition
A
• Advantage and Disadvantage
• SAR
• Classification
B
C
• Mechanism of action
• Therapeutic uses
• Pharmacokinetics
• Side effect

3.  Wide-spectrumβ-lactumbactericidal, chemical properties
being similar to the penicillins
 Cephamycins
: Streptomyces species or are synthetic
derivatives produced by substituting oxygen for sulfur
(methoxy group) in cephalosporin nucleus.
 Cephalosporium acremonium,
containing
common 7-aminocephalosporanic acid nucleus
the

4. Advantages
1. Non-toxic
2. ↓ risk of allergy.
3. More stable in
acidic medium
[less ring strain]
4. Higher
penicillinase
resistance.
5. Good activity ≠ Gve & G+ve
Disadvantage
1. Difficult to isolate
& purify [with
highly polar side
chain]
2. Lower potency
[less strained ring]
3. ↓ absorbed orally.

7. Mechanism of action:
Cephalosporins are bactericidal and have the
same mode of action as other beta-lactam
antibiotics (such as penicillin).
Cephalosporins disrupt the synthesis of
the peptidoglycan layer of bacterial cell walls.
 The peptidoglycan layer is important for cell
wall structural integrity.

8. These has been conventionally classified into four
generations. Based on Generation system
• This is based on chronological sequence of development,
but more importantly ,takes into consideration the overall
antibacterial spectrum as well as potency.
• First-generation cephalosporins are predominantly active
against Gram-positive bacteria, and successive generations
have increased activity against Gram-negative bacteria
(albeit often with reduced activity against Gram-positive
organisms).

9. First generation:
Developed in 1960, active against Gm+ weaker on Gm- orgnisms.
• Cephalothin: 1st cephalosporin used. (Parenteral)
active against: Streptococci, Staphylococci, gonococci,
meningococci, C.diptheriae and clostridia.
• Cephalexin: Orally active. commonly used.
(SPORIDEX)
• Cefadroxil: Excellent tissue penetration
(cefadrox)
Excreted unchanged in urine.
Dose adjustment in renal impaired patients.
• Cephazolin: Active against klebsiella and E.coli. (Parenteral)
Preferred parenteral 1st gen cephalosporin for
surgical prophylaxis ,
(ALCIZONE/ORIZOLIN)

10. Second generation:
• Cefuroxime: Resistant to Gm- beta lactamase (Parenteral)
Important use: meningitis caused by H. influenzae,
• Cefuroxime axetil: Ester of cefuroxime, effective oral
Uses: URTI, LRTI, UTI, skin and soft tissue infection
group B streptococci,salmonella, E.coli
(CEFTUM,ZOCEF)

11. Third generation
•
Broad-spectrum.
•
Active against Gm- enterobacteriacae.
•
Some are anti-pseudomal
•
Resistant to beta-lactamase.
Cefotaxim: (TAXIM/OMNATAX)

Prototype of third generation cephalosporin.

Widely distributed in body tissues and fluids, penetrates CSF best when
meninges are inflamed.
Uses: Aerobic Gm- bacteria infection, poor on anaerobes (B. fragilis),
Staphylococci and pseudomonas.
prominent indications: meningitis
11

12. Ceftriaxone:
• Longer duration of action. (MONOCEF/CEFERA)
• Good CSF penetration.
USES: Bacterial meningitis
Multi-Resistant typhoid fever
Complicated Uniary tract infection
Ceftazidime:
• Active against pseudomonas.
• Burn.
12
(CEFZID/TAZID)

13. Cefoperazone:
(CEFOMYCIN/NOVACIP)
• Strong anti-pseudomonal property.
• Cidal against S.typhi, B.fragilis.
• More susceptible to beta-lactamase.
USES: severe urinary, biliary, respiratory, skin-soft tissue infection,
meningitis and septicaemia.
Cefixime:
•
•
(ORIFIX/TAXIM-O/OMNATAX)
Orally active 3rd generation
Broad spectrum of action- enterobacteriaceae, H. influenzae, Strep
pyogenes. Not active against Staph and Pseudomonas .
Cefpodoxim proxetil.
(CEPODEM)
• Orally active 3rd generation
• Active against enterobacteriaceae and streptococci.
• Excellent outcome in RTI, UTI and soft-tissue infection.
Cefdinir:
(SEFDIN/ADCEF)
• Orally active
• 13 Excellent results in pneumonia,COPD,ENT & skin infections.

14. Fourth generation:
Cefepime:
(CEPIME/MEGAPIME)
• Highly resistant to beta-lactamase.
• Active against pseudomonas and Staph besides host of
organisms
Uses: Serious life-threatening hospital acquired pneumonia
Febrile neutropenia.
Bacterremia and septicaemia.
Cefpirome:
(CEFROM/CEFORTH)
• Treatment of serious and resistant hospital acquired
infections including septicaemia ,pneumonia.
• Covers some Gm+ organisms as well.

16. Cephalosporins are given parenterally and orally.
Extent of binding to plasma protein vary from one to another.
e.g. Cefazolin is 80% protein bound ( hence, long t1/2 )
Cephalexin is 10-15% protein bound
Relatively lipid insoluble ( like penicillins )
Hence,do not penetrate cells or the CNS, except for third
generations.
Mostly excreted unchanged by the kidney (glomerular &
tubular
secretion ), except, ceftazidime &
cefoperazone( glomerular)
Probenecid slows their elimination and prolong their half-live (
except Ceftazidime & cefoperazone)
Half-life 30-90 min; ceftriaxone 4-7 hr

17. 1. Alternative to penicillin in allergic
patients
2. Upper respiratory tract infections
and otitis media
cefaclor
cefuroxime axetil
cefixime
cefprozil
3. Septicaemia caused by G- bacteria
( P.aeruginosae)
A penicillin(eg.Piperacillin/
Ticarcillin)
+aminoglycoside
OR
A cephalosporin(eg.
ceftazidime ) + AG
4. Urinary tract infections
Cefuroxime, Cefixime
.
5. Prophlaxis in surgery
Appendectomy ( bowel
anaerobes ) eg. Cefoxitin
Obstetrical &gynecological,
urological, orthopedic
procedures, etc
( S. aureus & S. epidermidis )
eg. Cefazoline
6. Meningitis- N. Meningitidis
Ceftriaxone
Cefotaxime( pref. in neonate)

18. 1. Hypersensitivity reactions- most common
Anaphylaxis, bronchspasm, urticaria
Maculopapular rash- more common
2. Nephrotoxicity ; esp. cephradine
3. Thrombophlebitis ( i.v admin. )
4. Superinfections
5. Diarrhea-oral cephalosporins, cefoperazone,
ceftriaxone & moxalactam.
6. cefamandole, moxalactam & cefoperazone may cause:
a) bleeding disorders
b) Flushing, tachycardia, vomiting with alcohol intake

20. ^ "cephalosporin" at Dorland's Medical Dictionary
^ "Cephalosporin spectrum of
resistance". Retrieved 1 July 2012.
^ Stork CM (2006). "Antibiotics, antifungals,
and antivirals". In Nelson LH,

21. M. Zaharna Clin. Chem. 2009