The quinolones are a family of synthetic broad-spectrum antibacterial drugs. Quinolones, and derivatives, have also been isolated from natural sources and can act as natural antimicrobials and/or signalling molecules. Antifolates are drugs that antagonise (that is, block) the actions of folic acid (vitamin B9). Folic acid's primary function in the body is as a cofactor to various methyltransferases involved in serine, methionine, thymidine and purine biosynthesis.

1. BYBY
Dr.Dr. SAMINATHAN KAYAROHANAMSAMINATHAN KAYAROHANAM
M.PHARM, M.B.A, PhDM.PHARM, M.B.A, PhD
ANTIBIOTIC
(QUINOLONES, FOLIC ACID
ANTAGONISTS)
1
4

2. 2
NUM CONTENT SLIDE
1 INTRODUCTION TO QUINOLONES 4
2 ADVANTAGES OF QUINOLONES 5
3 CHEMICAL STRUCTURES OF QUINOLONES 6
4 CLASSIFICATION OF QUINOLONES 7
5 ANTIMICROBIAL SPECTRUM OF QUINOLONES 8
6 THERAPEUTIC APPLICATIONS OF CIPROFLOXACIN 9
7 MECHANISM OF QUINOLONES 10-13
8 SOME ADVERSE REACTIONS TO FLUOROQUINOLONES 14
9 INTRODUCTION TO SULFONAMIDE 15
10 CLASSIFICATION OF SULFONAMIDE 16,17
11 CHEMICAL STRUCTURES OF SULFONAMIDE 18
12 MECHANISM OF SULFONAMIDES AND TRIMETHOPRIM 19,20
13 SYNERGISM OF TRIMETHOPRIM AND
SULFAMETHOXAZOLE
21
14 SOME ADVERSE REACTIONS OF SULFONAMIDES 22
15 THERAPEUTIC APPLICATIONS OF CO-TRIMOXAZOLE 23
16 MECHANISM OF METHENAMINE 24

3. 3
LEARNING OUTCOME
1. Able to understand the quinolones and folic acid
antagonists.
2. List the common quinolones and folic acid drug
classification.
3. Abele to demonstrate the general mechanism of
quinolones and folic acid antagonists.
4. Able to describe the common quinolones and folic acid
antagonists adverse effects.
5. Able to understand the therapeutic application of
quinolones and folic acid antagonists.

4. 4
1. INTRODUCTION TO QUINOLONES
• The quinolones are a family of synthetic broad –
spectrum antibacterial drugs.
• The first generation of quinolones began with the
introduction of nalidixic acid in 1962 for treatment of
urinary tract infections in humans.
• Nalidixic acid was discovered by George Lesher.
• More than 100,000 quinolone compounds have been
synthesized and screened their pharmacological
activities. Currently, there are more than 20 quinolones
used in clinic.
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

5. 5
1) Effective against many organisms.
2) Well-absorbed orally.
3) Well-distributed in tissues.
4) Relatively long serum half-lives and minimal toxicity.
5) Deep-tissue and cell penetration.
6) Urinary tract infections, prostatitis.
7) Infections of the skin and bones.
8) Penicillin-resistant sexually transmitted diseases.
9) lower cost in synthesis with the excellent activities.
2. ADVANTAGES OF QUINOLONES
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

6. 6
Basic structure
QUINOLONE
First-generation
NALIDIXIC ACID Second-generation
CIPROFLOXACIN
Third-generation
LEVOFLOXACIN
Fourth-generation
MOXIFLOXACIN
3. CHEMICAL STRUCTURES OF QUINOLONES
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

7. 7
FIRST-GENERATION
CINOXACIN
NALIDIXIC ACID
OXOLINIC ACID
PIROMIDIC ACID
PIPEMIDIC ACID
ROSOXACIN
THIRD-GENERATION
BALOFLOXACIN
GREPAFLOXACIN
LEVOFLOXACIN
PAZUFLOXACIN
SPARFLOXACIN
TEMAFLOXACIN
TOSUFLOXACIN
SECOND-
GENERATION
CIPROFLOXACIN
FLEROXACIN
LOMEFLOXACIN
NADIFLOXACIN
NORFLOXACIN
OFLOXACIN
PEFLOXACIN
RUFLOXACIN
FOURTH-GENERATION
CLINAFLOXACIN
GATIFLOXACIN
GEMIFLOXACIN
MOXIFLOXACIN
SITAFLOXACIN
TROVAFLOXACIN
PRULIFLOXACIN
4. CLASSIFICATION OF QUINOLONES
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

8. 8
5. ANTIMICROBIAL SPECTRUM OF QUINOLONES
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

9. 9
6.THERAPEUTIC APPLICATIONS OF
CIPROFLOXACIN
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

10. 10
Con…
The fluoroquinolones
inhibit the replication
of bacterial DNA by
interfering with the
action of DNA gyrase
(topoisomerase II)
and topoisomerase IV
during bacterial
growth and
reproduction.
7.MECHANISM OF QUINOLONES
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

11. 11
7. MECHANISM OF QUINOLONES
Con…Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

12. 12
7.MECHANISM OF QUINOLONES
ConDr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

13. 13
7.MECHANISM OF QUINOLONES
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

14. 14
8.SOME ADVERSE REACTIONS TO
FLUOROQUINOLONES
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

15. 15
Sulfonamide drugs were the first antimicrobial drugs.
The first sulfonamide began in 1932.
The first official communication not published until
1935.
Cotrimoxazole was introduced in the mid-1970s, there
was a renewed interest in the sulfonamides.
The Sulfonamide drugs are seldom prescribed alone
except in developing countries, where they are still
employed because of their low cost.
Sulfa drugs differ from each other not only in their
chemical and physical properties but also in their
pharmacokinetic.
9. INTRODUCTION TO SULFONAMIDE
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

16. 16
Con…
10.CLASSIFICATION OF SULFONAMIDE
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

17. 17
1. SHORT ACTING SULFONAMIDE:
A. SULFADIAZINE
B. SULFADIMIDINE
C. SULFAMETHIZOLE
D. SULFAMETHOXAZOLE
E. SULFISOXAZOLE
F. SULFISOMIDINE OR SULFAISODIMIDINE
2. INTERMEDIATE ACTING SULFONAMIDE:
A. SULACETAMIDE
B. SULFADOXINE
3. LONG ACTING SULFONAMIDE:
A. SULFADOXINE
B. SULFAMETHOXY-PYRIDAZINE
C. SULFAMETOPYRAZINE
D. SULFAPHENAZOLE
10. CLASSIFICATION OF SULFONAMIDE
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

18. 18
11. CHEMICAL STRUCTURES OF SULFONAMIDE
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

19. 19
12. MECHANISM OF SULFONAMIDES AND TRIMETHOPRIM
Con…
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

20. 20
In many microorganisms, dihydrofolic acid is synthesized
from p-aminobenzoic acid (PABA), pteridine, and
glutamate .
All the sulfonamides currently in clinical use are synthetic
analogs of PABA. Because of their structural similarity to
PABA, the sulfonamides compete with this substrate for
the bacterial enzyme, dihydropteroate synthetase.
They thus inhibit the synthesis of bacterial dihydrofolic
acid and, thereby, the formation of its essential cofactor
forms. The sulfa drugs, including cotrimoxazole, are
bacteriostatic.
12. MECHANISM OF SULFONAMIDES AND
TRIMETHOPRIM
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

21. 21
13. SYNERGISM OF TRIMETHOPRIM AND SULFAMETHOXAZOLE
INHIBITION OF GROWTH OF ESCHERICHIA COLI
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

22. 22
14.SOME ADVERSE REACTIONS OF
SULFONAMIDES
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

23. 23
15. THERAPEUTIC APPLICATIONS OF CO-TRIMOXAZOLE
(SULFAMETHOXAZOLE PLUS TRIMETHOPRIM).
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

24. 24
Methenamine must
decompose at an acidic pH
of 5.5 or less in the urine,
thus producing
formaldehyde, which is
toxic to most bacteria.
The reaction is slow,
requiring 3 hours to reach
90 percent decomposition.
Methenamine should not be
used in patients with
indwelling catheters.
Bacteria do not develop
resistance to formaldehyde.
16. MECHANISM OF METHENAMINE
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

25. 25
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

26. 26
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

27. 27
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

28. 28
Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

29. 29 Dr.K.Saminathan.M.Pharm(Ph.D) , M.B.A (Ph.D)

30. 30Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

31. 31
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

32. 32
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

33. 33
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

34. 34
STEPS INVOLVED IN DNA REPLICATION IN PROKARYOTES
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

35. STEPS INVOLVED IN DNA REPLICATION IN PROKARYOTES
35
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

36. 36
STEPS INVOLVED IN DNA REPLICATION IN PROKARYOTES
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

37. 37
STEPS INVOLVED IN DNA REPLICATION IN PROKARYOTES
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D

38. 38
STEPS INVOLVED IN DNA REPLICATION IN PROKARYOTES
Dr.K.Saminathan.M.Pharm, M.B.A, Ph.D