Which antibiotic is associated with the least incidence of diarrhea?

From the Guidelines

Azithromycin is associated with the least incidence of diarrhea among the commonly prescribed antibiotics for treating travelers' diarrhea, with a reported incidence of gastrointestinal complaints, such as nausea or vomiting, of around 3% and <1%, respectively [ 1 ].

Key Considerations

• The selection of an empiric antibiotic should consider the likelihood of treatment efficacy, regional patterns of probable target pathogens and their antimicrobial resistance, safety and tolerance profile, simplicity of treatment regimen, and cost [ 1 ].
• Azithromycin has been shown to be superior to levofloxacin in achieving clinical cure in settings with high rates of FQ-resistant Campylobacter spp. [ 1 ].
• Azithromycin is generally well tolerated with minimal side effects, usually dose-related gastrointestinal complaints [ 1 ].

Comparison with Other Antibiotics

• FQs, such as ciprofloxacin, are associated with a higher incidence of gastrointestinal side effects, including nausea, vomiting, and diarrhea, as well as concerns about reduced benefit due to the likelihood of FQ-resistant Campylobacter spp. or Shigella spp. [ 1 ].
• Rifaximin, a nonabsorbable antibiotic, has demonstrated comparable efficacy to FQs in non-invasive TD caused by diarrheagenic E. coli, but is less effective for the treatment of invasive pathogens [ 1 ]. Some key points to consider when choosing an antibiotic for treating travelers' diarrhea include:
• The severity of the illness and the potential impact on the patient's activities and plans
• The regional patterns of probable target pathogens and their antimicrobial resistance
• The safety and tolerance profile of the antibiotic
• The simplicity of the treatment regimen and patient adherence
• The cost of the antibiotic [ 1 ].

From the FDA Drug Label

The most frequently reported drug related events, from clinical trials of all formulations, all dosages, all drug-therapy durations, and for all indications of ciprofloxacin therapy were nausea (2.5%), diarrhea (1.6%), liver function tests abnormal (1. 3%), vomiting (1%), and rash (1%). The incidence of treatment-related adverse events, primarily gastrointestinal, in all patients treated was 18% on azithromycin and 13% on penicillin. The most common side effects were diarrhea/loose stools (6% azithromycin vs. 2% penicillin), vomiting (6% azithromycin vs. 4% penicillin), and abdominal pain (3% azithromycin vs 1% penicillin). In the safety analysis of this study, the overall incidence of treatment-related adverse events, primarily gastrointestinal, was lower in the azithromycin treatment arm (31%) than in the amoxicillin/clavulanate arm (51%). The most common side effects were diarrhea (17% in the azithromycin arm vs 32% in the amoxicillin/clavulanate arm), and nausea (7% in the azithromycin arm vs. 12% in the amoxicillin/clavulanate arm).

Comparison of Diarrhea Incidence:

• Azithromycin: 6% (vs penicillin), 5-9% (vs clarithromycin), 17% (vs amoxicillin/clavulanate), 9% (noncomparative study)
• Ciprofloxacin: 1.6%

Based on the provided drug labels, ciprofloxacin is associated with the least incidence of diarrhea, with a reported rate of 1.6% 2.

From the Research

Antibiotic-Associated Diarrhea

• The provided studies do not directly compare the incidence of diarrhea associated with different antibiotics.
• However, some studies mention the tolerability and adverse events of certain antibiotics:
  • A study comparing azithromycin and ciprofloxacin for the treatment of uncomplicated Salmonella Typhi infection does not specifically mention diarrhea as an adverse event 3.
  • A study on the treatment of acute uncomplicated urinary tract infection in women with ciprofloxacin reports that the drug was well tolerated, but does not provide detailed information on gastrointestinal adverse events 4.
  • A study comparing the efficacy and tolerability of intravenous azithromycin plus ceftriaxone and intravenous levofloxacin for hospitalized patients with moderate to severe community-acquired pneumonia reports that both treatments were well tolerated, but does not provide specific data on diarrhea 5.
  • A meta-analysis on the treatment of Mycoplasma genitalium with azithromycin does not mention diarrhea as an adverse event 6.
  • A study on the use of single-dose azithromycin for the treatment of uncomplicated otitis media in children reports a low incidence of drug-related adverse events, including gastrointestinal events, but does not provide specific data on diarrhea 7.

Comparison of Antibiotics

• Based on the available data, it is not possible to determine which antibiotic is associated with the least incidence of diarrhea, as the studies do not provide direct comparisons or sufficient data on gastrointestinal adverse events.
• Further research would be needed to compare the incidence of diarrhea associated with different antibiotics.