The document discusses chemotherapy and antibiotics. It defines chemotherapy as treatment of infections with chemical agents, including antibiotics. Antibiotics are chemical substances produced by microorganisms that suppress or destroy other microbes. Antibiotics can be classified based on their spectrum of activity (broad or narrow) and their mechanism of action, such as inhibiting cell wall synthesis, cell membrane function, protein synthesis, or nucleic acid synthesis.

1. 3/31/2021 Z.M.NATHANI 1

2. INDEX
Chemotherapy
Chemotherapeutic agents
Antibiotics
Classification of antibiotics
Mechanism action of antibiotics
3/31/2021 Z.M.NATHANI 2

3. Chemotherapy
 Chemotherapy is defined as the treatment of
specific infections with chemical agents.
 In the broadest sense, it includes therapy with
antibiotics and also conditions where infection is
not involved e.g. malignancy.
A chemotherapeutic agent may be
 Bacteriostatic if it inhibits the growth of bacteria.
 Bactericidal if it destroys and kills the bacteria.
CHEMOTHERAPY
3/31/2021 Z.M.NATHANI 3

4. Chemotherapeutic agents include synthetic substances
Example
 Sulfonamides
 Antibiotics
e.g. penicillin.
CHEMOTHERAPEUTIC AGENTS
3/31/2021 Z.M.NATHANI 4

5. 3/31/2021 Z.M.NATHANI 5

6. Antibiotics are chemical substances synthesized
by various species of micro organisms and
produce suppression of growth and destruction
of other micro-organisms.
An antibiotic is said to have a narrow spectrum
of activity, if it is effective against either Gram-
positive or Gram-negative bacteria.
A broad spectrum antibiotic is effective against
both Gram-positive and Gram-negative bacteria
and also against rickettsia and chlamydia.
ANTIBIOTICS
3/31/2021 Z.M.NATHANI 6

7. BODY
3/31/2021 Z.M.NATHANI 7

8. OBTAINED
3/31/2021 Z.M.NATHANI 8

9. KILL
 Gram-positive or Gram-negative bacteria.
3/31/2021 Z.M.NATHANI 9

10. 1. Broad spectrum antibiotics
Tetracycline, Chloramphenicol
2. Narrow spectrum antibiotics
A. Effective against Gram-positive bacteria Erythromycin
Penicillin , Lincomycin, Vancomycin ,Novobiocin
B. Effective against Gram-negative bacteria
Streptomycin, Kanamycin
CLASSIFICATION OF
ANTIBIOTICS
3/31/2021 Z.M.NATHANI 10

11. 3. Antiprotozoal antibiotics
Paramomycin, Fumagillin
4. Antifungal antibiotics
Nystain, Amphotericin B, Griseofulvin,
Hamycin, Pimaricin
5. Antimalignant antibiotics
Actinomycin D
3/31/2021 Z.M.NATHANI 11

12. Antibiotics may act by any one of the
following mechanisms
1. By inhibiting cell wall synthesis
e.g. penicillins. cephalosporins, cycloserine.
2. By inhibiting the function of cell
membrane
e.g. polymyxin, novobiocin, nystatin.
MECHANISM ACTION OF
ANTIBIOTICS
3/31/2021 Z.M.NATHANI 12

13. 3. By inhibiting protein synthesis
e.g. chloramphenicol, tetracyclines,
erythromycin, lincomycin.
4. By inhibiting nucleic acid synthesis
e.g, actinomycin D, mitomycin C.
3/31/2021 Z.M.NATHANI 13

14. 3/31/2021 Z.M.NATHANI 14