What antibiotics are used to treat colitis (inflammation of the colon)?

From the Guidelines

Antibiotics should only be used in the treatment of colitis when a specific bacterial infection is identified, such as Clostridium difficile, and the first-line treatment for mild C. difficile infection is to stop the inducing antibiotic, with metronidazole (500mg three times daily for 10-14 days) or vancomycin (125mg four times daily for 10-14 days) as alternative options. For ulcerative colitis or Crohn's disease, which are inflammatory bowel diseases rather than infections, antibiotics are generally not recommended as first-line therapy 1. However, in cases of ulcerative colitis with severe complications or suspected secondary infection, ciprofloxacin (500mg twice daily) and metronidazole (500mg three times daily) may be used short-term, but the use of adjunctive antibiotics in hospitalized adult patients with acute severe ulcerative colitis without infections is not recommended due to the lack of evidence supporting their effectiveness and the potential for harm 1.

Some key points to consider when using antibiotics for colitis include:

• The potential for antibiotics to worsen colitis, particularly C. difficile-associated colitis, which often develops after antibiotic use disrupts normal gut flora 1
• The importance of proper diagnosis through stool tests, colonoscopy, or other appropriate evaluations to determine the specific cause of colitis 1
• The potential benefits of probiotics in maintaining gut flora balance alongside antibiotic treatment 1
• The need to complete any prescribed antibiotic treatment, even if symptoms improve before the course is finished, to ensure effective treatment and prevent the development of antibiotic-resistant bacteria 1

In terms of specific treatment guidelines, the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) recommends the following for the treatment of Clostridium difficile infection:

• Mild CDI: stop the inducing antibiotic, or metronidazole (500mg three times daily for 10-14 days) or vancomycin (125mg four times daily for 10-14 days) as alternative options 1
• Severe CDI: vancomycin (125mg four times daily for 10-14 days) as the first-line treatment, with metronidazole (500mg three times daily for 10-14 days) as an alternative option 1

It's also important to note that the American Gastroenterological Association (AGA) has published guidelines for the management of moderate to severe ulcerative colitis, which recommend the use of biologic agents, such as infliximab, adalimumab, and vedolizumab, as first-line therapy, with antibiotics only used in cases of suspected secondary infection or severe complications 1.

From the FDA Drug Label

Vancomycin Hydrochloride Capsules are indicated for the treatment of C. difficile-associated diarrhea. Vancomycin Hydrochloride Capsules are also used for the treatment of enterocolitis caused by Staphylococcus aureus (including methicillin-resistant strains) in adult and pediatric patients less than 18 years of age Vancomycin Hydrochloride Capsules for the treatment of colitis are for oral use only and are not systemically absorbed.

Vancomycin can be used to treat colitis caused by C. difficile or Staphylococcus aureus. The recommended dose for C. difficile-associated diarrhea is 125 mg administered orally 4 times daily for 10 days, and for staphylococcal enterocolitis, the total daily dosage is 500 mg to 2 g administered orally in 3 or 4 divided doses for 7 to 10 days 2.

From the Research

Antibiotics for Colitis

• The use of antibiotics for colitis depends on the cause of the infection, with most forms of infectious colitis being treatable with antimicrobials 3.
• For empiric treatment of febrile dysenteric diarrhea, invasive bacterial enteropathogens such as Shigella, Salmonella, and Campylobacter should be suspected, and adults may be treated empirically with 1000mg azithromycin in a single dose 4.
• Pathogen-specific antimicrobial therapy should be initiated for all forms of infectious colitis other than STEC (Shiga toxin-producing Escherichia coli) 4.

Treatment of Specific Types of Colitis

• For Clostridioides difficile infection (CDI), vancomycin is preferred over metronidazole for mild-to-moderate cases, with improved treatment response and lower cost per case treated 5.
• Intracolonic vancomycin enemas have been used as an adjuvant therapy for severe C. difficile colitis, with a response rate of 70% and no complications reported 6.

General Principles of Antibiotic Use

• Routine antibiotic use is not recommended for most adults with mild, watery diarrhea, as acute diarrhea is most often self-limited and caused by viruses 7.
• Antibiotics should be considered in patients who are older than 65 years, immunocompromised, severely ill, or septic, as well as in cases of suspected nosocomial infection or outbreak 7.