Relationship of plasma concentration and changes in the QTc interval in hospitalised patients receiving intravenous moxifloxacin for the treatment of community-acquired pneumonia

Abstract number: 1733_1565

le Berre M., Arvis P., Stass H., Choudhri S.

Background: It is well documented that moxifloxacin can prolong the QTc interval in some patients, although not to a clinically relevant degree. In Phase I studies, the magnitude of QTc prolongation showed a linear correlation with plasma moxifloxacin concentration, although with high variability. This analysis was designed to assess the relationship between plasma concentrations and changes in QTc in hospitalised patients with severe community-acquired pneumonia (CAP) requiring intravenous (IV) therapy.

Methods: All patients included in this analysis had CAP with a pneumonia severity index (PSI) Class of III to V and received IV moxifloxacin 400 mg (infused over 60 minutes) once daily. In all patients, 3 standard 12-lead ECG measurements were obtained within 6 hours prior to first infusion, within 30 minutes after the first infusion (day 1) and within 30 minutes after the third infusion (day 3). Plasma moxifloxacin concentrations were determined concomitantly using a HPLC validated method.

Results: 217 moxifloxacin-treated patients were valid for the analysis of QTcB changes between baseline and day 1 and 163 patients for the analysis between baseline and day 3. Mean QTcB (±SD) changes and the concentration effect relationship for the day 1 and day 3 groups are shown in the Table.

GroupMean DQTcB (ms, ±SD)aConcentration effect relationship
Slope [s]r2P   
Day 110.9±20.8-0.00010.00010.88
Day 38.5±27.9+0.00140.01340.15
aQT interval corrected for heart rate using Bazett's formula.

Conclusions: The QTcB changes observed were similar to those observed in previous CAP studies. There was no significant correlation between changes in QTcB and plasma moxifloxacin concentrations.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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