Related Experiment Video

Updated: Nov 22, 2025

A Protocol to Characterize the Morphological Changes of Clostridium difficile in Response to Antibiotic Treatment
12:58

A Protocol to Characterize the Morphological Changes of Clostridium difficile in Response to Antibiotic Treatment

Published on: May 25, 2017

9.2K

Fidaxomicin Use for Clostridium Difficile Infection Probably Decreases the Effect of Coumadin® in Elderly

Samyak Dhruv1, Abhishek Polavarapu2, Vivek Gumaste2

  • 1Internal Medicine, Staten Island University Hospital, Staten Island, USA.

Cureus
|January 11, 2021
PubMed

Insights

A patient experienced reduced warfarin effectiveness during Clostridium difficile infection (CDI) treatment with fidaxomicin. This unexpected interaction required increased warfarin dosage to maintain therapeutic international normalized ratio (INR).

Area of Science:

  • Infectious Diseases
  • Pharmacology
  • Internal Medicine

Background:

  • Clostridium difficile infection (CDI) incidence is declining, but community-acquired cases remain stable.
  • Warfarin, an anticoagulant, requires careful monitoring of the international normalized ratio (INR).
  • Fidaxomicin is a treatment for recurrent CDI, with no known drug interactions with warfarin.

Observation:

  • An elderly patient with recurrent CDI was treated with fidaxomicin.
  • During fidaxomicin treatment, the patient exhibited a significant decrease in INR.
  • The patient was concurrently taking warfarin (Coumadin®).

Findings:

  • Fidaxomicin treatment for recurrent CDI was associated with diminished warfarin efficacy.
  • Therapeutic INR levels were only achieved after increasing the warfarin dosage.
  • This case suggests a potential drug interaction between fidaxomicin and warfarin, contrary to existing literature.

Implications:

  • Clinicians should be aware of a potential interaction between fidaxomicin and warfarin.
  • Close INR monitoring is crucial in patients receiving both fidaxomicin and warfarin.
  • Further research is needed to elucidate the mechanism of this interaction and its clinical significance.
Keywords:
clostridium difficile infectioncoumadinfidaxomicin

More Related Videos

Fecal Microbiota Transplantation via Colonoscopy for Recurrent C. difficile Infection07:06

Fecal Microbiota Transplantation via Colonoscopy for Recurrent C. difficile Infection

Published on: December 8, 2014

27.4K
Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R2029106:51

Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291

Published on: December 10, 2016

12.9K

Related Concept Videos

Anticoagulant Drugs: Vitamin K Antagonists and Direct Oral Anticoagulants01:18

Anticoagulant Drugs: Vitamin K Antagonists and Direct Oral Anticoagulants

Oral anticoagulants are vital tools in preventing and treating blood clotting disorders. This diverse class of medications can be categorized as vitamin K antagonists, exemplified by warfarin, and direct thrombin inhibitors (DTIs), such as dabigatran, as well as factor Xa inhibitors, including rivaroxaban.
Warfarin, a prominent vitamin K antagonist family member, exerts its effect by inhibiting the enzyme VKORC1 (vitamin K epoxide reductase complex 1). By hindering this enzyme, warfarin...
1.6K
Drug Dosing: Geriatric Patients01:15

Drug Dosing: Geriatric Patients

Elderly individuals encompass a diverse population with varying degrees of age-related physiological changes. Defining the elderly presents challenges, as the geriatric population is often arbitrarily categorized as individuals older than 65. However, many individuals in this group lead active and healthy lives, with an increasing number surpassing 85 years and falling into the older elderly category. Physiological changes associated with aging impact performance capacity and homeostatic...
105
Drugs for Treatment of Crohn's Disease in IBD Using Immunomodulatory Agents01:29

Drugs for Treatment of Crohn's Disease in IBD Using Immunomodulatory Agents

Crohn's disease is an inflammatory bowel disorder marked by chronic inflammation of the GI tract. Various treatment strategies for Crohn's disease are employed, such as immunomodulatory agents, glucocorticoids, and biologics or anti-TNF therapy. Azathioprine (Imuran), a commonly used immunomodulatory drug for Crohn's disease, is converted in the body to mercaptopurine, which inhibits purine biosynthesis and cell proliferation. Both are utilized in severe cases of Inflammatory Bowel...
323
Drugs Affecting GI Tract Motility: Antimicrobials as Antidiarrheal Agents01:18

Drugs Affecting GI Tract Motility: Antimicrobials as Antidiarrheal Agents

Acute diarrhea, a common gastrointestinal disturbance, is characterized by the rapid evacuation of fluid stools, leading to an excessive weight in fluid. This condition typically arises from disorders affecting intestinal water and electrolyte transport. It can be triggered by an increased osmotic load within the intestine, excessive secretion of electrolytes and water, mucosal exudation of protein and fluid, or altered intestinal motility. The primary risks of acute diarrhea are dehydration...
306
Drugs for Treatment of Ulcerative Colitis in IBD01:29

Drugs for Treatment of Ulcerative Colitis in IBD

Ulcerative colitis is a chronic inflammatory condition primarily affecting the colon and rectum. The primary drugs used in the treatment of ulcerative colitis are aminosalicylates. They exhibit anti-inflammatory and immunosuppressive properties. They modulate inflammatory mediators and inhibit the activity of nuclear factor κB (NF-κB). Aminosalicylates also reduce inflammation by inhibiting prostaglandin and leukotriene production and decreasing neutrophil chemotaxis and superoxide...
311
Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Metabolism01:18

Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Metabolism

Geriatric patients show significant variation in how their bodies process medications, which can change how effective and safe treatments are. The liver is the primary organ where drug metabolism occurs, involving two main types of chemical reactions: phase I and II. Phase I metabolism is driven by the cytochrome P450 enzyme system, which includes key types such as CYP3A, CYP2D6, and CYP2C9. Research indicates that while aging doesn't notably alter the levels or activity of these enzymes, it...
86