This document discusses cephalosporins, a class of antibiotics. It describes the different generations of cephalosporins and their antibacterial spectra. Some key points covered include: cephalosporins have similar mechanisms and resistance as penicillin; common side effects include hypersensitivity, diarrhea, and nephrotoxicity; uses include respiratory, urinary, and skin infections as well as surgical prophylaxis and meningitis; and examples are provided of cephalosporins with anti-anaerobic or anti-pseudomonal activity.

2. Cephalosporins
Dr Chintan Doshi

3. Classification and antibacterial spectrum
1st Generation 2nd Generation 3rd Generation 4th Generation
D
R
U
G
S
Parenteral Cephalothin
cefazolin
Oral Cephalexin
Cefadroxyl
Cefuroxime
cefoxitin
Cefuroxime
axetil
cefaclor
Cefotaxime
Ceftriaxone
Ceftazidime
Cefoperazone
Ceftizoxime
Cefixime
Cefpodoxime
proxetil
Cefdinir
Ceftibuten
Ceftamet pivoxil
Cefepime
cefpirome
S
p
e
c
t
r
u
m
Gm +ve
Gm - ve
anaerobes
pseudomonas
More active +++
Weak +/-
++
++
Weak +/-
More active +++
S
a
m
e
a
s
3
r
d
--
--
Active Less active
-- Active
Highly resistant
to β-lactamases

4. Cephalosporins with anti-anaerobic activity Cefotetan, cefoxitin
Cefoperazone, ceftizoxime
Cephalosporins with anti-pseudomonal activity Cefoperazone
Ceftazidime
Cefepime

5. Most cephalosporins are excreted by kidney
Ceftriaxone, cefoperazone are excreted mainly in bile
Cephalospron with best CSF penetration- Ceftriaxone

6. • Mechanism of action
– Same as penicillin
• Mechanism of resiatance
– Alteration of PBP
– Production of 𝝱- lactamase
– Not able to reach target site

7. ADR
Hypersensitivity Lower than Pn, Cross reactivity to Pn
Diarrhea Max with;Oral – , Parenteral – those excreted in bile
Nephrotoxicity
Bleeding Due to hypoprothrombinaemia, Cefoperazone, ceftriaxone
Disulfiram like reaction Cefoperazone
Pain and thrombophlebitis

8. Uses
• As alternatives to penicillins
– ENT, upper respiratory and cutaneous infections
• Respiratory, urinary and soft tissue infections
caused by gram-negative organisms
• Penicillinase producing staphylococcal
infections

9. Contd.
• Septicaemias
• Surgical prophylaxis: cefazolin
• Meningitis
– i.v. cefotaxime/ceftriaxone is combined with
ampicillin or vancomycin
– Ceftazidime + gentamicin for pseudomonas
meningitis
• Gonorrhoea:ceftriaxone first choice (single
dose)
• Chancroid:Ceftriaxone first choice

10. Contd.
• Typhoid
– ceftriaxone and cefoperazone injected i.v.
– Cefixime:orally
• Mixed aerobic-anaerobic infections in
– Cancer patients
– colorectal surgery
– obstetric complications
• Hospital acquired infections

11. Contd.
• Prophylaxis and treatment of infections in
neutropenic patient

12. MCQ
• Which of the following drugs acts by
inhibiting cell wall synthesis?
• (a) Erythromycin
• (b) Cephalosporins
• (c) Chloramphenicol
• (d) Sulfonamides

13. • Which of the following is a fourth generation
cephalosporin?
• (a) Ceftriaxone
• (b) Cefaclor
• (c) Cefepime
• (d) Cefuroxime

14. • Jarisch-Herxheimer reaction is seen in
syphilis with:
• (a) Tetracyclines
• (b) Penicillins
• (c) Co-trimoxazole
• (d) Sulfonamides

15. • Penicillinase resistant penicillin is:
• (a) Methicillin
• (b) Ampicillin
• (c) Carbenecillin
• (d) Ticarcillin

16. • Which of the following drugs is an anti-
pseudomonal penicillin?
• (a) Cephalexin
• (b) Dicloxacillin
• (c) Piperacillin
• (d) Cloxacillin

17. • Which of the following is used in the
prophylactic treatment of rheumatic heart
disease:
• (a) Ampicillin
• (b) Penicillin-G
• (c) Bezathine penicillin
• (d) Phenoxy-methyl penicillin

18. • All of the following have beta lactam ring
except:
• (a) Penicillin
• (b) Linezolid
• (c) Cefotaxime
• (d) Imipenem

19. • Which one of the following is true about the
beta lactam antibiotics:
• (a) All are based on the 6-amino-penicillanic
acid structure
• (b) Include amikacin
• (c) Are safe in pregnancy
• (d) Are uniformly ineffective against
pseudomonas aeruginosa

20. Thanks