Third- vs. fourth-generation quinolones: which are best in the long-term?

According to a study published in the September issue of the Journal of Cataract and Refractive Surgery, differences in the pharmacokinetic and pharmacodynamic properties of quinolone antibiotics may affect the incidence of endophthalmitis following cataract surgery.

Michael K. Jensen from the University of Utah Hospital, Salt Lake City, US and co-workers from the University of Chicago, Illinois, US conducted a retrospective cross-sectional prevalence study to determine the differences in endophthalmitis rates with prophylactic use of third- and fourth-generation fluoroquinolones in cataract surgery over a ten-year period.

A nosocomial infectious reporting database was used to report occurrences of endophthalmitis and a retrospective analysis of prospectively collected data was performed to determine endophthalmitis rates. In addition, a comparative analysis of endophthalmitis rate versus postoperative quinolone prescribed for reported cases, was carried out.

Between January 1997 and December 2007, 29,276 patients underwent phacoemulsification and 40 cases of postoperative bacterial endophthalmitis were reported. Between January 1997 and August 2003, the endophthalmitis rate associated with the use of third-generation fluoroquinolones (ciprofloxacin and ofloxacin) was 0.197%. The rate from September 2003 to December 2007 associated with fourth-generation fluoroquinolones (gatifloxacin and moxifloxacin) was 0.056%. There was a statistically significant difference between third- and fourth generation drugs (p=0.0011). Of fourth-generation fluoroquinolone infections, 0.015% and 0.1% were associated with gatifloxacin and moxifloxacin, respectively, demonstrating a statistically significant difference (p=0.040).

It was concluded that differences in the pharmacokinetic and pharmacodynamic properties of third- and fourth-generation drugs may effect the rate of postoperative endophthalmitis. Furthermore, the significant difference between gatifloxacin and moxifloxacin will require further investigation.