Chemotherapy involves using chemical substances to treat diseases, particularly cancer and microbial infections. The term was coined by Paul Ehrlich, who developed the first effective treatment for syphilis called Salvarsan. Chemotherapeutic agents can be synthetic chemicals or substances produced by microorganisms. Some common classes of antimicrobial agents used in chemotherapy include sulphonamides, fluoroquinolones, tetracyclines, and others. These work by interfering with bacterial growth and survival through various mechanisms such as inhibiting enzymes or DNA synthesis. While effective against many infections, these agents can sometimes cause side effects and the development of drug resistance remains a concern.

1. Chemotherapy

2. Chemotherapy
1. Chemo : Chemical
2. Therapy: Treatment to cure disease or
disorder
The term chemotherapy was coined
by Paul Ehrlich ( Father of
Chemotherapy)
Chemotherapy is use of chemicals to
treat disease; more specifically to kill
microorganisms and cancer cells

3. Magic Bullet Paul Ehrlich
Salvarsan(Arsphenamine) : An arsenical
compound and the first effective treatment
for syphilis ( Treponema pallidum)

4. Chemotherapy
Antibiotics
Substances that are
of biological origin
Chemotherapeutic agents
Synthetic chemical

5. Drug Resistance
Drug resistance is the reduction in
effectiveness of a medication or drug to
cure a disease or condition. More
commonly, antimicrobial resistance.
It is the ability of microbes, such as
bacteria, viruses, parasites, or fungi, to
survive in the presence of a chemical drug
that that was previously effective in
killing it or inhibiting its growth.
Kabhi Kabhi lagta
hai….Apunnhi Bhgawan hai

6. How do they do it ?

7. Antimicrobial Agents
Sulphonamides
&
Trimethoprim
Fluoroquinolones
Nitrofurantoin
Penicillins Cephalosporins

8. Antimicrobial Agents
Tetracyclines
Chloramphenicol
Macrolides
Aminoglycosides Clindamycin

9. History of Sulphonamides(1932) German Pathologist : Gerhard Domagk
Prontosil
● Azo Dye
● Chemically it is ; Sulfonamido-chrysoidine
● It's a Prodrug

10. Prontosil (Prodrug) Sulphanilamide (Active)

11. Antimicrobial Agents : Sulphonamides
First antimicrobial agent
effective against Pyogenic
bacterial infection

12. Mechanism of action
Dihydropteroate synthase
Glutamic acid

13. Classification
Short acting : Sulfadiazine (4-8 Hours)
Intermediate acting : Sulfamethoxazole ( 8-12 Hours)
Long acting : Sulphadoxine (7 days)
Special Purpose : 1.Sulfacetamide sodium (Eye infection)
2. Mafenide (Skin infection)
3. Silver sulfadiazine ( Skin infection)
4. Sulfasalazine (Rheumatoid arthritis and Ulcerative colitis-IBD)
DAPSONE : Used in leprosy
COTRIMOXAZOLE (1 : 5) : Trimethoprim + Sulfamethoxazole

14. Combination therapy : Cotrimoxazole
Dihydropteroate synthase
Glutamic acid

15. Uses
1. Eye infection
2. Skin infection
3. GIT infection
4. Meningitis
5. Urinary tract infection
6. Leprosy
7. Respiratory tract infection
8. Malaria
Side effects
1. Steven Johnson syndrome/Skin rashes
2. Urticaria or Crystalluria
3. Leucopenia (Decrease in WBC count)
4. Folic acid deficiency
5. Aplastic anemia (Damage to bone marrow)
6. Hypersensitivity (Allergy)
7. Hepatitis
8. Kernicterus (Brain damage in newborn)

16. Antimicrobial Agents : Quinolones
Synthetic antimicrobials active
against Gram negative bacteria
First synthetic quinolone derivative : Nalidixic acid (1960)
Use: Urinary antiseptic
Demerits: Low potency, Low tissue penetration,Restricted
spectrum,Highly susceptible to bacterial resistance
Adverse effects : Headache, Vertigo, Visual disturbance

17. Fluoroquinolones
● Second generation fluoroquinolones : Norfloxacin, Ciprofloxacin, Ofloxacin, Pefloxacin, Lomefloxacin
● Third generation Fluoroquinolones : Levofloxacin, Moxifloxacin, Gemifloxacin, Prulifloxacin,
Sparfloxacin
● Fourth generation : Trovafloxacin
● High potency
● Expanded spectrum
● Slow development of resistance
● Better penetration

18. Mechanism of action
DNA gyrase
R.I.P
Fluoroquinolone
Blocks DNA Synthesis

19. Side effects
Uses
1. Gonorrhoea (N.Gonorrhoeae)
2. Conjunctivitis
3. Typhoid (S.typhi)
4. GIT infection
5. Meningitis
6. Urinary tract infection
7. Respiratory tract infection
8. Pneumonia
9. TB (M.Tuberculosis)
Nausea
Vomiting
Anorexia
Dizziness
Headache
Insomnia
Hypersensitivity

20. Antimicrobial Agents : Tetracyclines
Broad spectrum antibiotics obtained
from Soil microorganisms.
Streptomyces(Actinomycetes)
species:
Gram positive bacteria
1st Tetracycline compound :
Chlortetracycline(1948)
Source : Streptomyces aureofaciens
Features : Bitter solids, Slightly water soluble,
Unstable in aqueous solution

21. Ribosomes
70S ribosomes
Larger unit 50S
Smaller unit 30S
80S Ribosomes

22. Mechanism of action
Tetracycline
Protein synthesis blocked which
leads to death of microorganism

23. Classification
Short acting :
Oxytetracycline : S. rimosus
Tetracycline : Semisynthetic
Intermediate acting :
Demeclocycline : Streptomyces aureofaciens
Long acting :
Doxycycline : Semisynthetic
Minocycline : semisynthetic
Photosensitivity
And Diabetes
insipidus
Tooth discoloration
(Abnormal tooth colour)
Ototoxicity and renal
toxicity

24. Uses
1. Plague
2. Cholera
3. Urinary tract infection
4. Sexually transmitted diseases
5. Ulcers
6. Relapsing fever
7. Pneumonia

25. To be continued……………