Systematic Review on Antibiotic Treatment Durations

Introduction

A recent systematic review published in Pharmacotherapy examined the effectiveness of short versus long courses of antibiotics for treating bacterial infections. As antibiotic resistance becomes a growing concern worldwide, antimicrobial stewardship programs are increasingly being implemented. Given the various factors that contribute to the rise of resistant bacteria, it is crucial to continuously update best practices. One proposed strategy is to minimize the duration of antibiotic treatments to decrease their impact on the microbiome.

Evidence Supporting Shorter Treatment Durations

The body of evidence indicating the efficacy of shorter antibiotic courses is expanding. However, there remains significant resistance among prescribers to adopt this approach. Many clinicians and patients hold the belief that reducing the length of antibiotic treatment might contribute to bacterial resistance. In contrast, shorter treatment durations may actually decrease antibiotic exposure and, by extension, the likelihood of developing resistance.

Review by Pharmacists

Two pharmacists from Philadelphia, Pennsylvania, conducted a systematic review comparing short and long antibiotic courses across six common infections. Their findings were published in Pharmacotherapy.

Comparative Analysis of Antibiotic Treatments

Treatments for Community-Acquired Pneumonia

Several studies have assessed the effectiveness of fluoroquinolone treatment durations for community-acquired pneumonia (CAP). Results indicated that shorter treatment durations were as effective as longer ones. For instance, amoxicillin demonstrated comparable efficacy with treatment durations ranging from three to eight days. Similarly, azithromycin administered for three days proved as effective as the conventional five-day regimen. In the early 2000s, recommendations for treating hospital-acquired or ventilator-associated pneumonia (HAP/VAP) were revised from 14-21 days to 8-15 days, with studies showing similar mortality rates within this adjusted timeframe.

Treatments for Intra-Abdominal Infections

Intra-abdominal infections generally require treatment for four to seven days; however, standard practice often involves longer durations that exceed the resolution of symptoms. The STOP-IT trial compared long and short regimens for these infections, revealing that the primary endpoints—death and infectious complications—were similar between a four-day course and a longer duration that extended two days post-symptom resolution.

Treatments for Skin Infections

Skin and soft tissue infections (SSTIs) are typically managed through drainage, cleaning, and antibiotic therapy. Researchers have investigated the necessity of antibiotic treatment following these procedures, finding high success rates without antibiotics. Current guidelines suggest a five-day course for uncomplicated skin infections instead of ten days, although additional research is needed to validate this recommendation.

Treatments for Urinary Tract Infections

Recommended treatment durations for uncomplicated urinary tract infections (UTIs) vary by drug class. Fosfomycin can resolve a UTI in a single dose, while nitrofurantoin typically requires a minimum of five days. In contrast, sulfamethoxazole/trimethoprim and fluoroquinolones generally necessitate three days, and beta-lactam antibiotics may require treatment periods of three to seven days due to their pharmacodynamics. For complicated UTIs, studies indicate that shorter courses of fluoroquinolones may be adequate; for example, five days of levofloxacin was found to be as effective as ten days of ciprofloxacin, and seven days of ciprofloxacin showed similar results to fourteen days of the same antibiotic.

Conclusion

In conclusion, evidence supports the use of shorter antibiotic courses for various bacterial infections. Despite the tendency of prescribers to extend treatment durations beyond the recommendations of the Infectious Diseases Society of America, reducing antibiotic treatment durations where appropriate may help mitigate the emergence of resistant bacteria.

Reference

Jessica Caporuscio, PharmD
Hanretty AM, Gallagher JC. Shortened Courses of Antibiotics for Bacterial Infections: A Systematic Review of Randomized Controlled Trials. Pharmacotherapy. 2018.