Here are some basic info regarding antibiotics generations

1. GENERATIONS OF
ANTIBIOTICS
Presented by: Tahmid Faisal
Lecturer, Dept. of Pharmacy
Stamford University Bangladesh

2. What is antibiotic?
Antibiotics are chemical compounds used to kill
(Bactericidal) or inhibit(Bacteriostatic) the
growth of infectious organisms (like Bacteria,
protozoa)

3. How Different types of Antibiotics
work ?

4. Generation of Antibiotics
Generation term comes only in case of
Penicillins and Cephalosporins (Beta lactam
antibiotics) and depending on their action on
the cell wall of gram positive and gram negative
bacteria they are classified by using terms ‘
Broad spectrum’ and ‘Narrow spectrum’
antibiotics.

5. Gram +ve Vs Gram –ve Bacteria

6. 1st Generation Antibiotics
• Have a narrow spectrum of clinical use (this
means there are only a few organisms that
they are able to successfully treat with this
class of penicillin)
• good for common gram-positive bacteria that
cause ear and throat infections, venereal
diseases of gonorrhea and syphilis, and staph
infections due to Staphylococcus aureus that
cause abscesses, endocarditis and pneumonia

7. • A very high number of the drugs in this group
are resistant to organisms that produce
penicillinase [Penicillinase is an enzyme that
some bacteria are capable of producing. This
enzyme is also called a beta-lactamase and it
inactivates some of the penicillins.]

8. Examples
• Penicillin G and Penicillin V
• Cephalosporins:
Cephazolin
Cephalothin
Cephapirin
Cephalethin
Cephradin
Cephadroxin

9. 2nd Generation Antibiotics
• Have an extended or Intermediate spectrum
of clinical use (Some gram +ve and gram-ve).
• Work equally as well as penicillin G class plus
effective against Escherichia coli, Proteus
mirabilis and Haemophilus influenzae which
are associated with urinary, respiratory and
ear infections
• Not very effective against penicillinase-
producing organisms

10. Examples
• Penicillin: Amoxicillin, Ampicillin
• Cephalosporin:
Cefuroxime
Cephamandole
Cephoxitin
Cephaclor
Cephrozil
Loracarbef

11. 3rd Generation Antibiotics
• Third generation cephalosporin drugs are
broad spectrum and the effective against both
gram positive and gram negative bacteria.
However their optimum activity is against
gram negative bacteria.
• used in the treatment of serious urinary,
respiratory and bacteremic infections due to
gram-negative Pseudomonas aeruginosa and
Proteus vulgaris
• not resistant to penicillinase-producing
organisms

12. Examples
• Penicillin: carbenicillin and ticarcillin
• Cephalosporins:
Cephixime
Cephtriaxone
Cephotaxime
Cephtizoxime
Cephtazidime

13. 4th Generation Antibiotics
• These are extended spectrum antibiotics. They
are not resistant to Beta lactumase producing
microorganisms.
• used for serious infections due
to Pseudomonas aeruginosa, Proteus vulgaris,
Klebsiella pneumoniae and Bacteroides
fragilis in combination with other antibiotics
• Examples: Cephipime

14. 5th Generation Antibiotics
• Extended spectrum Antibiotics.
• Examples:
Cephtaroline : Pneumonia, skin and soft tissue
infection
Cephtobiprole: Methicillin resistant
Staphylococcus aureus.