An Overview of Fluoroquinolones

22 The fluoroquinolones are broad-spectrum bactericidal agents inhibiting DNA 23 synthesis. They are active against gram positive and gram negative organisms like P. 24 aeruginosa, Mycoplasma, Chlamydia, Staphylococci and a few of the Streptococci. They are 25 useful in the treatment of pneumonia, urinary tract infections, bacterial diarrhea, and skin and 26 soft tissue infections. The use of quinolones began with its first generation that consisted of 27 nalidixic acid. From that time, a large number of newer fluoroquinolones having a variety of 28 structures and a broader spectrum of activity have been developed forming the five 29 generations. The more number of fluoroquinolones developed and its widespread usage is 30 attributed to its high bioavailability and tissue penetration. Moreover, the development of 31 resistance to the most commonly used antibiotics has led to the need for alternatives. The 32 various derivatives of fluoroquinolone have varying levels of activity depending on the 33 various groups attached at different positions. Generating a derivative with increased activity 34 will help to reduce the Minimum Inhibitory Concentration (MIC), thereby reducing the 35 possibility of developing resistance to it. This paper gives an overview of fluoroquinolones, 36 their mechanism of action, their uses, resistance development and their adverse effects. 37