From Needle to Sachet: Fosfomycin Versus Amikacin for Cystoscopy Prophylaxis

Area of Science:

• Urology
• Infectious Diseases
• Pharmacology

Background:

• Antibiotic prophylaxis is standard practice before outpatient cystoscopic procedures (CPE).
• Parenteral amikacin and oral fosfomycin are commonly used prophylactic agents.
• Comparative data on their efficacy and safety are crucial for clinical decision-making.

Purpose of the Study:

• To compare the efficacy and safety of amikacin versus fosfomycin for antibiotic prophylaxis before outpatient cystoscopy.
• To evaluate the incidence of symptomatic and culture-positive urinary tract infections (UTIs) post-procedure.
• To assess the occurrence of adverse drug reactions (ADRs) associated with each antibiotic.

Main Methods:

• Retrospective comparative observational study of 2914 adult patients undergoing outpatient CPE.
• Patients received either single-dose intravenous amikacin (15 mg/kg) or single-dose oral fosfomycin trometamol (3 g).
• Primary outcome: symptomatic UTI within 14 days; Secondary outcomes: culture-positive UTI, ADRs. Statistical analysis included chi-square, Fisher's exact, and independent t-tests.

Main Results:

• Symptomatic UTI rates were similar: 6.7% for amikacin vs. 8.2% for fosfomycin (p=0.18).
• Culture-positive UTI rates were comparable (2.1% vs. 2.0%, p=0.91).
• Amikacin group had higher rates of acute kidney injury (2.6% vs. 0.1%, p<0.001), while fosfomycin group had more gastrointestinal ADRs (8.3% vs. 2.3%, p<0.001).

Conclusions:

• Oral fosfomycin is as effective as amikacin in preventing post-cystoscopy UTIs.
• Fosfomycin exhibits a more favorable safety profile compared to amikacin.
• Oral fosfomycin is a safe and effective alternative for prophylaxis in outpatient cystoscopy, especially for patients at risk of aminoglycoside toxicity.