Fluoroquinolones

MECHANISM:
              Fluroquinolones inhibit DNA GYRASE and TOPOISOMERASE-4. 
Thus inhibiting replication of DNA .

CLASSIFICATION:

1st generation - Norfloxacin, Lomefloxacin
                        ( active against few gram -ve organism )
2nd generation - Ciprofloxacin , Ofloxacin
                        ( active against all gram -ve organism )
3rd generation - Sparfloxacin, Levofloxacin , Gatifloxacin 
               ( active against all gram -ve organism and few gram +ve)
4th generation - Moxifloxacin , Trovafloxacin
                (active against all gram -ve and gram +ve )

Pharmacokinetics :

1. All drugs can be given orally and parenterally . 
2. Metabolized by liver
3. Moxifloxacin and Trovafloxacin excreted in feces 
4. Others are excreted via urine

Uses:

1. Norfloxacin is excreted in urine in large quantities , hence used in UTI
2. Ciprofloxacin and Ofloxacin used in gonorrhoea , pseudomonas , anthrax , meningococcal meningitis , TB 
3. Levofloxacin , Gatifloxacin , Sparfloxacin are active against all gram -ve , few gram +ve and atypical microoraganisms . Hence used in respiratory infections
4. Moxifloxacin amd Trovafloxacin are the broadest spectrum antibiotic.

ADVERSE EFFECTS:

1. GI distress
2. Affect cartilages and hence not used in children below 18 yrs 
3. They cause tendinitis 
4. Photosenstivity
5. Seizures
6. Moxifloxacin and Trovafloxacin causes hepatotoxicity.