Rates of torsades de pointes associated with ciprofloxacin, ofloxacin, levofloxacin, gatifloxacin, and moxifloxacin.

STUDY OBJECTIVE

To compare the rates of torsades de pointes associated with ciprofloxacin, ofloxacin, levofloxacin, gatifloxacin, and moxifloxacin administration.

DESIGN

Retrospective database analysis.

INTERVENTION

Evaluation of reported rates of torsades de pointes in patients who received these quinolones between January 1, 1996, and May 2, 2001.

MEASUREMENTS AND MAIN RESULTS

In the United States, 25 cases of torsades de pointes associated with these quinolones (ciprofloxacin 2, ofloxacin 2, levofloxacin 13, gatifloxacin 8, moxifloxacin 0) were identified. Ciprofloxacin was associated with a significantly lower rate of torsades de pointes (0.3 cases/10 million prescriptions, 95% confidence interval [CI] 0.0-1.1) than levofloxacin (5.4/10 million, 95% CI 2.9-9.3, p<0.001) or gatifloxacin (27/10 million, 95% CI 12-53, p<0.001 for comparison with ciprofloxacin or levofloxacin). When the analysis was limited to the first 16 months after initial U.S. approval of the agent, the rates for levofloxacin (16/10 million) and gatifloxacin (27/10 million) were similar (p>0.5).

CONCLUSION

Levofloxacin should be administered with caution in patients with risk factors for QT prolongation. Gatifloxacin should be avoided in the same patient population, and the recommended dosage of 400 mg/day should not be exceeded.