Moxifloxacin-Induced Clostridium difficile-Associated Diarrhea

Douglas N. Carroll, Pharm.D.


Pharmacotherapy. 2003;23(11) 

In This Article

Abstract and Introduction

A 22-year-old woman was admitted to the hospital with pneumonia, urinary tract infection, anemia, thrombocytopenia, and leukocytosis. After receiving moxifloxacin for 5 days, she experienced diarrhea with cramping and abdominal pain. She was diagnosed with Clostridium difficile-associated diarrhea (CDAD) after C. difficile toxin was identified in a stool specimen. Metronidazole was begun, and the CDAD resolved with continued moxifloxacin administration. Virtually any antibiotic can lead to development of CDAD through disruption of the normal colonic flora, allowing for overgrowth of C. difficile. Although moxifloxacin is generally well tolerated, clinicians should be aware of its potential for inducing CDAD.

Moxifloxacin is a third-generation fluoroquinolone that possesses increased activity against gram-positive cocci while retaining activity against gram-negative bacteria and atypical organisms.[1,2] This agent is useful in the treatment of many respiratory tract infections caused by susceptible bacteria; it is also useful for treating uncomplicated skin and skin structure infections.[2] In general, moxifloxacin is well tolerated. The most common adverse effects are gastrointestinal, such as diarrhea, nausea, and vomiting. Other adverse effects include central nervous system disturbances and skin reactions; however, these occur infrequently and are usually minor.[2,3]

Clostridium difficile-associated diarrhea (CDAD) can develop after administration of almost any antibiotic. The most commonly implicated agents are penicillins, cephalosporins, and clindamycin.[4,5,6,7] The fluoroquinolone antibiotics are thought to induce CDAD infrequently.[4,6] However, several drugs in this class have been implicated, such as cipro-floxacin,[8,9,10] levofloxacin,[11] ofloxacin,[12,13] and, in a recent report, moxifloxacin.[14]