The basic pharmacophore, or active structure, of the fluoroquinolone class is based upon the<unk>  ring system. Various substitutions made to the<unk>  ring resulted in the development of numerous fluoroquinolone drugs. The addition of the fluorine atom at C-6 distinguishes the successive-generation fluoroquinolones from the first-generation<unk> s, although examples are known that omit the atom while retaining antibacterial activity. Pharmacokinetics + Pharmacokinetics of newer fluoroquinolones following a single oral dose Drug Dosagea(mg) (%) Cmax(μg/mL) tmax(h) (μg • h/mL) (h) (L/kg) Proteinbinding (%) Excretedunchanged (%) Dose adjustment Ciprofloxacin 500750 7070 2.303.00 1.21.2 10.114.0 3.53.5 3.53.5 3030 3434 YesYes NoNo Garenoxacin 400600 92 5.010.4 1.2 6096.7 14.29.8 75 40 Gatifloxacin 400 96 3.86 1.5 33.8 8.0 1.8 20 76 Yes No Gemifloxacin 320640 7070 1.192.29 1.21.2 7.315.9 8.08.0 3.53.5 6060 2727 YesYes NoNo Levofloxacin 500750 9999 5.087.13 1.71.7 48.082.0 6.96.9 1.11.1 3131 8383 YesYes Moxifloxacin 200400 8686 1.163.34 1.71.7 15.433.8 12.112.1 3.33.3 4747 1919 NoNo NoNo a = Dosage applies only to Cmax and . The other parameters an average of the values available in the literature irrespective of dosage.
Quinolone antibiotic
Polypeptide antibiotic
Beta-lactam antibiotics
Lipase inhibitors
Nonsteroidal anti-inflammatory drug
Antiviral drug
Protease inhibitor 
Antibiotic