• Introduction and Definition
• Advantage and Disadvantage
• Mechanism of action
• Therapeutic uses
• Side effect
Wide-spectrumβ-lactumbactericidal, chemical properties
being similar to the penicillins
: Streptomyces species or are synthetic
derivatives produced by substituting oxygen for sulfur
(methoxy group) in cephalosporin nucleus.
common 7-aminocephalosporanic acid nucleus
2. ↓ risk of allergy.
3. More stable in
[less ring strain]
5. Good activity ≠ Gve & G+ve
1. Difficult to isolate
& purify [with
highly polar side
2. Lower potency
[less strained ring]
3. ↓ absorbed orally.
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.
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
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.
• Cefadroxil: Excellent tissue penetration
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 ,
• 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
Active against Gm- enterobacteriacae.
Some are anti-pseudomal
Resistant to beta-lactamase.
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
• Longer duration of action. (MONOCEF/CEFERA)
• Good CSF penetration.
USES: Bacterial meningitis
Multi-Resistant typhoid fever
Complicated Uniary tract infection
• Active against pseudomonas.
• 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.
Orally active 3rd generation
Broad spectrum of action- enterobacteriaceae, H. influenzae, Strep
pyogenes. Not active against Staph and Pseudomonas .
• Orally active 3rd generation
• Active against enterobacteriaceae and streptococci.
• Excellent outcome in RTI, UTI and soft-tissue infection.
• Orally active
• 13 Excellent results in pneumonia,COPD,ENT & skin infections.
• Highly resistant to beta-lactamase.
• Active against pseudomonas and Staph besides host of
Uses: Serious life-threatening hospital acquired pneumonia
Bacterremia and septicaemia.
• Treatment of serious and resistant hospital acquired
infections including septicaemia ,pneumonia.
• Covers some Gm+ organisms as well.
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
Mostly excreted unchanged by the kidney (glomerular &
secretion ), except, ceftazidime &
Probenecid slows their elimination and prolong their half-live (
except Ceftazidime & cefoperazone)
Half-life 30-90 min; ceftriaxone 4-7 hr
1. Alternative to penicillin in allergic
2. Upper respiratory tract infections
and otitis media
3. Septicaemia caused by G- bacteria
ceftazidime ) + AG
4. Urinary tract infections
5. Prophlaxis in surgery
Appendectomy ( bowel
anaerobes ) eg. Cefoxitin
( S. aureus & S. epidermidis )
6. Meningitis- N. Meningitidis
Cefotaxime( pref. in neonate)
1. Hypersensitivity reactions- most common
Anaphylaxis, bronchspasm, urticaria
Maculopapular rash- more common
2. Nephrotoxicity ; esp. cephradine
3. Thrombophlebitis ( i.v admin. )
5. Diarrhea-oral cephalosporins, cefoperazone,
ceftriaxone & moxalactam.
6. cefamandole, moxalactam & cefoperazone may cause:
a) bleeding disorders
b) Flushing, tachycardia, vomiting with alcohol intake
^ "cephalosporin" at Dorland's Medical Dictionary
^ "Cephalosporin spectrum of
resistance". Retrieved 1 July 2012.
^ Stork CM (2006). "Antibiotics, antifungals,
and antivirals". In Nelson LH,