This document discusses cephalosporin antibiotics. It begins with an introduction to cephalosporins, noting that they are structurally related to penicillin and are broad spectrum, semisynthetic, and bactericidal. It then discusses the classification of first, second, and third generation cephalosporins. The document covers the mechanism of action, resistance issues, pharmacokinetics, clinical uses for infections like pneumonia and UTIs, and potential adverse effects like hypersensitivity reactions. It concludes with information on carbapenem and monobactam antibiotics developed to treat beta-lactamase producing bacteria.

1. Prof. Shaikh Abusufiyan
Assistant Professor,
AIKTC-School of Pharmacy,
New Panvel-410206
Antibiotics: Cephalosporin
Pharma Learning Forever

2. At the end of this e-learning session you are able to…
A. Discuss history and Mechanism
of action of Cephalosporin
B. Give classification and Explain
pharmacology of Cephalosporin.
Copyright @shaikhabusufiyan2021

3. Cephalosporins and Cephamycin's
l It is structurally and pharmacologically
related to the penicillin.
l They are
l Water soluble
l Broad spectrum
l Semisynthetic
l Bactericidal antibiotics

4. l It is derived from 7 amino-cephalosporanic acid (7-ACA).

5. l Properties:
- Relatively acid stable
- Vary in susceptibility to beta lactamase

6. • Second generation
Cefaclor
- Cefamandole
- Cefuroxime
• First generation
- Cephalexin
- Cephadroxil
- Cephazolin
CLASSIFICATION OF CEPHALOSPORINS
• Third generation:
- Cefotaxime
- Moxalactam
- Ceftizoxime

7. Antibacterial spectrum:
l In general progression from the 1st to 3rd generation it
exhibit
- broadening gram -ve spectrum
- loss of efficacy against gram +ve organism
- greater efficacy against resistant organism
- Increase in cost

8. Mechanism of action:
l It has penicillin like action
l Interfere with bacterial peptidoglycan synthesis.
l They also inhibit mucopeptide synthesis in bacterial
cell wall
Rendering it defective and osmotically unstable

9. Resistance
l Resistance to this group of drugs has increased
because of plasmid mediated production of beta lactamase.
l Resistance also occurs when there is decrease penetration
of the drugs
as a result of alteration to outer membrane proteins or
mutation of the binding site protein.

10. Pharmacokinetics
l Routes:
- Some are given orally
- Most are given parentally i.e IM or IV
l Distribution:
- Wide distribution
- Cefotaxime, Cefuroxime and ceftriaxone cross BBB.

11. l Execration:
- Mostly via kidney
- 40 % of ceftriaxone is eliminated in the bile

12. Activity II: Self learning of e-content

13. Clinical uses
• Septicaemia e.g. Cefuroxime, cefotaxime
• Pneumonia caused by susceptible organisms
• Meningitis e.g. ceftriaxone, cefotaxime

14. Clinical uses
• Biliary tract infection
• Urinary tract infection: (especially in pregnancy,
or in patients unresponsive to other drugs)
• Sinusitis (e.g. cefadroxil).

15. Unwanted effects
• Hypersensitivity reactions: very similar to those that occur with
penicillin
• Cross-reactions: about 10% of penicillin-sensitive individuals will have
allergic reactions to cephalosporins.

16. Unwanted effects
• Nephrotoxicity: (especially with
cefradine) as has intolerance to alcohol.
• Diarrhoea: With oral cephalosporins
and cefoperazone.

17. OTHER β-LACTAM ANTIBIOTICS:
CARBAPENEMS AND MONOBACTAMS
• Developed to deal with β-lactamase-producing Gram-
negative organisms resistant to penicillin.
CARBAPENEMS
• Eg. Imipenem
MoA:
• Acts in the same way as the other β-lactams

18. • It has a very broad spectrum of antimicrobial activity
• ‘Methicillin-resistant' staphylococci are less susceptible
• Also resistant strains of P. aeruginosa have emerged during
therapy.
• Imipenem was originally resistant to all β-lactamases but
some organisms now have chromosomal genes that code for
imipenem-hydrolysing β-lactamases.

19. Unwanted effects:
• Similar to those seen with other β-lactams such as:
• Nausea and vomiting --> frequently seen
• Neurotoxicity --> Occur with high plasma
concentrations

20. MONOBACTAMS
• The main monobactam is Aztreonam, a simple monocyclic
β-lactam with a complex substituent at R3 which is
resistant to most β-lactamases.
• This has an unusual spectrum- active only against
Gram-negative aerobic rods
• It has no action against Gram-positive organisms or
anaerobes.

21. • It is given parenterally
• Plasma half-life - 2 hours.
Unwanted effects:
• Similar to those of other β-lactam antibiotics
• But this agent does not cross-react immunologically
with penicillin and its products
does not cause allergic reactions in penicillin-sensitive
individuals.

22. Q&A: Activity II
Q.1 Name cephalosporin use for meningitis
Q.2Give one example of carbepinam?
Q.3 Identify antibiotic category which is active only against Gram-negative
aerobic rods
Q.4 True or false. Monobactam antibiotic active against gram positive bacteria.

23. Reference:
• H.P Rang. M M Dale, J.M Ritter, R.J Flower, G Henderson.
Pharmacology, Seventh Edition. Elsevier Churchill Livengston
Publication. Page no:626-629.

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Copyright @ Presentation
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• The presentation is for education purpose only, don’t use the same for any legal
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