Moxifloxacin - modern fluoroquinolone in the treatment of community-acquired respiratory tract infections. Moxifloxacin is an extended-spectrum fluoroquinolone which has an antibacterial spectrum that covers all of the major upper and lower respiratory tract pathogens. It is one of the most active fluoroquinolones against pneumococci, including those resistant to penicillin and macrolides. Moxifloxacin achieves good penetration into respiratory tissues and fluids. It has exellent bioavailability, and its long t1/2permits administration in single daily doses. The oncedaily, short-course administration is a guarantee for a better compliance by the patient and makes development of resistance lees likely. The clinical efficacy and safety of moxifloxacin has been shown in controlled studies of acute exacerbations of chronic bronchitis, community-acquired pneumonia and acute sinusitis. Moxifloxacin 400 mg once daily achieved bacteriological and clinical succes rates of apporoximately 90% or higher. It was as effective as, or more effective than, comparators including clarithromycin, cefuroxime axetil and high dose amoxicillin in these trials. The most commonly reported adverse events in patients receiving moxifloxacin are gastrointestinal disturbances.