Which antibiotic is more effective?

From the Guidelines

Azithromycin is the most effective antibiotic for the treatment of travelers' diarrhea, particularly in cases of dysentery or acute watery diarrhea with greater than mild fever, due to its high efficacy and low resistance rates compared to fluoroquinolones (FQs) 1.

Key Considerations

When selecting an empiric antibiotic for travelers' diarrhea, several factors should be considered, including:

• Likelihood of treatment efficacy and rapidity of response
• Regional patterns of probable target pathogens and their antimicrobial resistance
• Safety and tolerance profile of the antibiotic
• Simplicity of treatment regimen and patient adherence
• Cost

Efficacy of Azithromycin

Azithromycin has been shown to be superior to levofloxacin in achieving clinical cure in Thailand, where FQ-resistant Campylobacter spp. are prevalent 1. Additionally, azithromycin has demonstrated effective and comparable cure rates with shigellosis, another common agent causing dysentery.

Safety and Tolerance

Azithromycin is generally well tolerated with minimal side effects, usually dose-related gastrointestinal complaints 1. Incident or worsening nausea or vomiting are exacerbated by the primary gastrointestinal infection, and are more common than in the treatment of non-gastrointestinal infections.

Comparison to Other Antibiotics

FQs, such as ciprofloxacin, have been shown to be effective in the treatment of travelers' diarrhea, but their use is limited by the increasing prevalence of FQ-resistant Campylobacter spp. and other enteric pathogens 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.

From the FDA Drug Label

For the 304 patients analyzed in the modified intent to treat analysis at the Day 21 to 24 visit, the clinical cure rate for 3 days of azithromycin was 85% (125/147) compared to 82% (129/157) for 10 days of clarithromycin For the 594 patients analyzed in the modified intent to treat analysis at the Day 10 visit, the clinical cure rate for 3 days of azithromycin was 88% (268/303) compared to 85% (248/291) for 10 days of amoxicillin/clavulanate. Azithromycin was clinically and microbiologically statistically superior to penicillin at Day 14 and Day 30 with the following clinical success (i.e., cure and improvement) and bacteriologic efficacy rates

• Comparing azithromycin to other antibiotics:
  • Azithromycin vs. clarithromycin: azithromycin had a slightly higher clinical cure rate (85% vs. 82%) 2
  • Azithromycin vs. amoxicillin/clavulanate: azithromycin had a slightly higher clinical cure rate at Day 10 (88% vs. 85%), but similar rates at Day 28 (71.5% vs. 71.5%) 2
  • Azithromycin vs. penicillin: azithromycin was statistically superior to penicillin at Day 14 and Day 30 2
• Conclusion: Azithromycin appears to be at least as effective as, or slightly more effective than, the compared antibiotics in certain studies. However, the differences in efficacy are generally small, and the choice of antibiotic should be based on individual patient needs and other factors. 2

From the Research

Comparison of Antibiotic Effectiveness

• The effectiveness of antibiotics can be compared based on their spectrum of activity, clinical efficacy, and tolerability.
• Levofloxacin, a fluoroquinolone antibacterial agent, has been shown to be effective against a broad range of Gram-positive and Gram-negative bacteria, including penicillin-resistant Streptococcus pneumoniae 3.
• Ceftriaxone, a third-generation cephalosporin, has also been demonstrated to be effective in the treatment of various infections, including those of the urinary and lower respiratory tracts 4.

Treatment of Community-Acquired Pneumonia

• For community-acquired pneumonia (CAP) requiring hospitalization, guidelines recommend either a beta-lactam and macrolide combination or a fluoroquinolone, such as levofloxacin 5.
• Studies have shown that levofloxacin monotherapy is as efficacious as combination ceftriaxone-erythromycin therapy in the treatment of patients hospitalized with CAP 5, 6.
• A multicenter, open-label, randomized trial compared levofloxacin monotherapy with azithromycin and ceftriaxone combination therapy in hospitalized adults with moderate to severe CAP, and found that levofloxacin was at least as effective as the combination regimen 6.

Choice of Antibiotic

• The choice of antibiotic depends on various factors, including the severity of the infection, the causative pathogen, and the patient's underlying health conditions.
• Levofloxacin has been shown to be effective against a wide range of pathogens, including those that are resistant to other antibiotics 3, 5.
• Ceftriaxone is also effective against a variety of pathogens, but may not be as effective against certain strains of Streptococcus pneumoniae that are resistant to penicillin 4, 7.