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The interaction of moxifloxacin and warfarin in three elderly patients

Kieran Anthony O'Connor1, Denis O'Mahony

  • 1Department of Geriatric Medicine, Cork University Hospital, Wilton, Co. Cork, Cork, Ireland

European Journal of Internal Medicine
|August 16, 2003
PubMed

Insights

Moxifloxacin, a broad-spectrum antibiotic, may pose a serious risk when combined with warfarin, particularly in elderly patients. This drug interaction differs from findings in healthy volunteers.

Area of Science:

  • Pharmacology
  • Geriatric Medicine
  • Infectious Diseases

Background:

  • Moxifloxacin is an oral 8-methoxyquinolone antibiotic with broad-spectrum antimicrobial activity.
  • Clinical trials suggest moxifloxacin is generally safe and well-tolerated.

Purpose of the Study:

  • To describe a potentially serious drug interaction between moxifloxacin and warfarin.
  • To highlight differences between clinical observations in elderly patients and existing study data in healthy volunteers.

Main Methods:

  • Case series describing three frail, elderly patients experiencing an interaction.
  • Comparison of patient population characteristics with healthy volunteers from previous drug interaction studies.

Main Results:

  • A potentially serious interaction between moxifloxacin and warfarin was observed in three frail, elderly patients.
  • The patient population (frail, elderly) differs significantly from healthy volunteers previously studied for this interaction.

Conclusions:

  • The observed moxifloxacin-warfarin interaction in elderly patients may be clinically significant.
  • Caution is advised when prescribing moxifloxacin to elderly patients, especially those on warfarin, due to potential differences from healthy volunteer studies.

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