Clinical utility of the new fluoroquinolones for treating respiratory and urinary tract infections

Increasing antimicrobial resistance among most common urinary and respirato ry tract pathogens has been the catalyst for the development of fluoroquino lones that are effective against these prevalent resistant organisms. Impor tant attributes of the newly developed fluoroquinolones include once-daily dosing, maintained extensive tissue penetration and high oral bioavailabili ty added to targeted antibacterial activities, all pharmacodynamic characte ristics that may reduce the need for parenteral therapy or prevent patients being hospitalised. Some fluoroquinolones also offer same-dose bioequivale ncy between iv. and oral formulations, a feature that allows iv.-to-oral do sing (step-down or 'switch' therapy) without the need for dosage adjustment s. These features suggest that the newer fluoroquinolones may be near-ideal agents for the empirical treatment of many common infections. This review discusses the efficacy and clinically relevant antimicrobial and pharmacoki netic qualities of the fluoroquinolones in comparison with other agents tra ditionally used to treat patients with urinary and respiratory tract infect ions.