These are synthetic antimicrobial having a quinolones structure. These are active against most of the gram negative bacteria. In 1960s the first membered of this group, Nalidixic acid, was introduced . Flouroquinolones have: High potency Expanded antimicrobial spectrum Better tissue penetration Good tolerability profile Very low resistance development 1. NALIDIXIC ACID It was the first member in quinolones. It was active against gram negative bacteria. It acts by inhibiting bacterial DNA gyrase. It is bacterial in nature. It is given orally. It attains good concentration in gut, lumen, hence useful in diarrhea. NALIDIXIC ACID CONTD… It is most commonly seen in children. And causes neurological toxicity present as headache, drowsiness and vertigo and contraindicated in infants and G6PD deficient patients. It is given in a dose of 0.5-1g TDS/QID 2. FLUOROQUINOLONES Fluoroquinolones are quinolones antimicrobials having one or more fluorine substituitions. The first generation fluoroquinolones have one fluoro substitution and were developed in 1980s. The second generation fluoroquinolones have additional fluoroquinolones have additional fluoro substitution, which extended the antimicrobial activity and were developed in 1990s. MECHANISM OF ACTION The fluoroquinolones inhibits the enzyme DNA gyrase in Gram-negative micro-organism and topoisomerase IV in gram positive micro-organism. This lead to the bactericidal effects of fluoroquinolones. RESISTANCE The resistance to fluoroquinolones develops when the bacteria produce a DNA gyrase or topoisomerase IV which have reduced affinity for fluoroquinolones or the bacteria produce efflux pumps across bacterial memberane which shunt out the fluoroquinolones from the bacterial cells. CLASSIFICATION FIRST GENERATION FLOUROQUINOLONES : Norfloxacin Ofloxacin Ciprofloxacin Pefloxacin SECOND GENERATION FLUOROQUINOLONES: Levofloxacin Moxifloxacin Lomefloxacin Gemifloxacin Sparfloxacin Prulifloxacin PHARMACOKINETICS These are given both by oral and intravenous route. These have good absorption, when given empty stomach and food delays the absorption. These drugs have good tissue penetrability. These are excreted in urine by glomerular filtration as well as tubular secretion. INDICATIONS Bacterial gastroenteritis Typhoid fever UTI Gonorrhoea Chancroid Bone, Soft tissue and gynaecological infections Respiratory infections Tuberculosis Gram negative septicemia and meningitis Conjuctivitis COMMON ADVERSE EFFECTS GI SYSTEM: Nausea, vomiting, bad taste and anorexia CNS: Headache, anxiety, insomnia, restlessness and impairment of concentrations. Skin: Rash, photosensitivity Contraindicated in pregnancy. They should be used in caution in children as a few cases of joint pain and swelling have been reported and a risk of cartilage damage is suspended. FIRST GENERATION FLUROQUINOLONES SECOND GENERATION FLUROQUINOLONES DRUG INTERACTIONS Antacids decrease the absorption

1. QUINOLONES

2. INTRODUCTION
• These are synthetic antimicrobial having a quinolones
structure.
• These are active against most of the gram negative
bacteria.
• In 1960s the first membered of this group, Nalidixic acid,
was introduced .
• Flouroquinolones have:
High potency
Expanded antimicrobial spectrum
Better tissue penetration
Good tolerability profile
Very low resistance development

3. 1. NALIDIXIC ACID
• It was the first member in quinolones. It was active against
gram negative bacteria. It acts by inhibiting bacterial DNA
gyrase. It is bacterial in nature.
• It is given orally. It attains good concentration in gut,
lumen, hence useful in diarrhea.
•

4. NALIDIXIC ACID CONTD…
• It is most commonly seen in children. And causes
neurological toxicity present as headache, drowsiness
and vertigo and contraindicated in infants and G6PD
deficient patients.
• It is given in a dose of 0.5-1g TDS/QID

5. 2. FLUOROQUINOLONES
• Fluoroquinolones are quinolones antimicrobials having one
or more fluorine substituitions.
• The first generation fluoroquinolones have one fluoro
substitution and were developed in 1980s.
• The second generation fluoroquinolones have additional
fluoroquinolones have additional fluoro substitution, which
extended the antimicrobial activity and were developed in
1990s.

6. MECHANISM OF ACTION
• The fluoroquinolones inhibits the enzyme DNA gyrase in
Gram-negative micro-organism and topoisomerase IV in
gram positive micro-organism. This lead to the bactericidal
effects of fluoroquinolones.

7. RESISTANCE
• The resistance to fluoroquinolones develops when the
bacteria produce a DNA gyrase or topoisomerase IV
which have reduced affinity for fluoroquinolones or
the bacteria produce efflux pumps across bacterial
memberane which shunt out the fluoroquinolones
from the bacterial cells.

8. CLASSIFICATION
• FIRST GENERATION
FLOUROQUINOLONES :
1. Norfloxacin
2. Ofloxacin
3. Ciprofloxacin
4. Pefloxacin
• SECOND GENERATION
FLUOROQUINOLONES:
1. Levofloxacin
2. Moxifloxacin
3. Lomefloxacin
4. Gemifloxacin
5. Sparfloxacin
6. Prulifloxacin

9. PHARMACOKINETICS
• These are given both by oral and intravenous route.
• These have good absorption, when given empty stomach
and food delays the absorption. These drugs have good
tissue penetrability.
• These are excreted in urine by glomerular filtration as well
as tubular secretion.

10. INDICATIONS
• Bacterial gastroenteritis
• Typhoid fever
• UTI
• Gonorrhoea
• Chancroid
• Bone, Soft tissue and gynaecological infections
• Respiratory infections
• Tuberculosis
• Gram negative septicemia and meningitis
• Conjuctivitis

11. COMMON ADVERSE EFFECTS
• GI SYSTEM: Nausea, vomiting, bad taste and anorexia
• CNS: Headache, anxiety, insomnia, restlessness and
impairment of concentrations.
• Skin: Rash, photosensitivity
• Contraindicated in pregnancy.
• They should be used in caution in children as a few cases of
joint pain and swelling have been reported and a risk of
cartilage damage is suspended.

12. FIRST GENERATION
FLUROQUINOLONES
DRUG HALF LIFE ROUTE DOSE
CIPROFLOXACIN 3-5 ORAL, IV, TOPICAL 250-750 mg BD
100-200mg BD
0.3% EYE DROPS
NORFLOXACIN 4-6 ORAL 400mg BD
OFLOXACIN 5-8 ORAL, IV, TOPICAL 200-400 mg BD
200mg BD
0.3% EYE DROPS
PEFLOXACIN 8-14 ORAL OR IV 400mg BD (oral, IV)

13. SECOND GENERATION
FLUROQUINOLONES
DRUG HALF LIFE ROUTE DOSE
LEVOFLOXACIN 8 ORL,IV,TOPICAL 500mg OD
0.5% EYE DROPS
LOMEFLOXACIN 9 ORAL TOPICAL 400mG OD
0.3% EYE DROPS
SPARFLOXACIN 16-30 ORAL, TOPICAL 200-400mg OD
0.3% eye drops
MOXIFLOXACIN 10-15 ORAL, IV, TOPICAL 400 mg OD
0.5% eye drops
GEMIFLOXACIN 7 ORAL 320 mg OD
PRULIFLOXACIN 10-12 ORAL 600mg OD
GATIFLOXACIN 7-14 ORAL,TOPICAL 400 mg OD
0.5% eye drops.

14. DRUG INTERACTIONS
• Antacids decrease the absorption of fluoroquinolones.
• Ciprofloxacin inhibits the metabolism of caffeine,
theophylline and warfarin and leads to serious
toxicity.

15. NURSING IMPLICATIONS
• Patient should be advised to avoid direct sun light.
• Patient should be advised to take plenty of water
during the course.
• Patient should be advised to take medicine in empty
stomach or with little meals for better absorption.
• Patient should be regularly enquired about any side
effects.