What antibiotics have the least likelihood of causing diarrhea?

From the Guidelines

Azithromycin is the antibiotic with the least likelihood of causing diarrhea due to its targeted mechanism of action and lower rates of gastrointestinal side effects compared to other antibiotics. According to the guidelines for the prevention and treatment of travelers' diarrhea, azithromycin has been shown to be effective in treating dysentery and acute watery diarrhea with minimal side effects, including gastrointestinal complaints 1. The study found that azithromycin has a lower rate of nausea and vomiting compared to other antibiotics, with rates of 3% and <1%, respectively 1.

Key Considerations

• Azithromycin is generally well tolerated with minimal side effects, making it a preferred choice for patients who are at risk of developing diarrhea while taking antibiotics 1.
• The antibiotic has been shown to be effective in treating dysentery and acute watery diarrhea, with a high level of evidence supporting its use as a first-line agent in these cases 1.
• Other antibiotics, such as fluoroquinolones, may have a higher risk of causing diarrhea due to their broader spectrum of activity and potential to disrupt the normal gut microbiome 1.

Recommendations

• Azithromycin should be considered the first-line agent for patients who are at risk of developing diarrhea while taking antibiotics, due to its targeted mechanism of action and lower rates of gastrointestinal side effects 1.
• Patients taking azithromycin should be advised to take the medication with food, unless specifically instructed otherwise, to reduce the risk of gastrointestinal side effects.
• Probiotics, such as Lactobacillus or Saccharomyces boulardii, may also be considered to help prevent diarrhea in patients taking antibiotics, including azithromycin 1.

From the FDA Drug Label

Clostridium difficileAssociated Diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including clarithromycin, and may range in severity from mild diarrhea to fatal colitis. The FDA drug label does not answer the question.

From the Research

Antibiotics with Low Likelihood of Causing Diarrhea

• Azithromycin and clarithromycin are alternatives to conventional macrolides and have been shown to be better tolerated, with less toxicity and lower incidence of adverse gastrointestinal effects, including diarrhea 2, 3, 4, 5
• The newer macrolides, such as azithromycin, clarithromycin, dirithromycin, and roxithromycin, may offer several advantages over erythromycin, including lower incidence of adverse gastrointestinal effects 3
• Azithromycin and clarithromycin have been found to have good oral bioavailability, excellent tissue penetration and persistence, and long elimination half-lives, which allow for once-daily or twice-daily dosing, potentially reducing the risk of diarrhea 5
• However, it is essential to note that antibiotics, including azithromycin and clarithromycin, can still cause diarrhea and other gastrointestinal side effects, and their use should be limited to patients with specific indications, such as entero-invasive or severe choleriform diarrhea 6

Comparison of Macrolide Antibiotics

• Azithromycin and clarithromycin have distinct advantages over erythromycin, including increased antimicrobial activity against certain organisms and lower incidence of adverse gastrointestinal effects 3, 5
• Dirithromycin and roxithromycin are also newer macrolide antibiotics that have been studied, but less information is available on their specific effects on diarrhea 3

Adverse Effects of Antibiotics

• Antibiotic prescription for acute diarrhea is not devoid of risks, including individual risks for the patient, such as allergy, gastrointestinal side effects, and Clostridium difficile infection 6
• The most frequently reported adverse effects for azithromycin and clarithromycin have been nausea, diarrhea, and abdominal pain 5