Care must be taken when comparing fluoroquinolone ADR rates, as these may derive from different periods, different countries and differing patient groups. For example, clinical trial data on fluoroquinolone ADR incidences consistently show overall rates of 2-4% for Japanese patients and significantly greater rates (> 10%) for US based studies. The ADR profile of levofloxacin after treatment of > 200 million patients worldwide contains no unpleasant surprises and, indeed, compares very favorably with other members of the class and other antibiotic groups.

However, levofloxacin appears to have a lower incidence of fluoroquinolone class effects despite such considerations (9, 38, 41, 42, 45, 47, 48). ADR rates for fluoroquinolones introduced in the 1990s were of the order of 25%. For levofloxacin, the highest figure for related ADRs in US trials was 9.9% (46).