From the Guidelines
For a 67-year-old female on apixaban with a UTI, I recommend nitrofurantoin (Macrobid) 100 mg twice daily for 5 days as first-line empiric therapy for uncomplicated UTI. This recommendation is based on the guidelines from the Infectious Diseases Society of America and the European Society for Microbiology and Infect Diseases, which suggest nitrofurantoin monohydrate/macrocrystals as an appropriate choice for therapy due to minimal resistance and propensity for collateral damage, with efficacy comparable to 3 days of trimethoprim-sulfamethoxazole 1.
Key Considerations
- Nitrofurantoin has minimal interaction with apixaban, reducing the risk of bleeding complications.
- Alternatives include trimethoprim-sulfamethoxazole (Bactrim) DS twice daily for 3 days, though this carries a slightly higher bleeding risk with apixaban.
- Fosfomycin 3 g single-dose sachet is another option with minimal drug interactions, but it appears to have inferior efficacy compared with standard short-course regimens 1.
- If pyelonephritis is suspected or the patient has systemic symptoms, a fluoroquinolone like ciprofloxacin 500 mg twice daily for 7 days may be needed, though this requires closer monitoring of anticoagulation.
Treatment Approach
- Ensure adequate hydration during treatment.
- Complete the full course of antibiotics even if symptoms resolve quickly.
- Nitrofurantoin is preferred because it concentrates in the urinary tract with minimal systemic absorption, reducing the risk of bleeding complications when used with anticoagulants like apixaban, while maintaining excellent coverage against common uropathogens including E. coli 1.
Monitoring and Follow-up
- Monitor for signs of bleeding or other adverse effects.
- Follow up with the patient to ensure resolution of symptoms and to assess for any potential complications.
From the Research
Recommended Empiric Antibiotic for UTI
For a 67-year-old female on apixaban, the recommended empiric antibiotic therapy for acute uncomplicated bacterial cystitis is:
- A 5-day course of nitrofurantoin
- A 3-g single dose of fosfomycin tromethamine
- A 5-day course of pivmecillinam 2
Considerations for Antibiotic Resistance
High rates of resistance to trimethoprim-sulfamethoxazole and ciprofloxacin preclude their use as empiric treatment of UTIs in several communities, particularly if patients were recently exposed to them or are at risk of infections with extended-spectrum β-lactamases (ESBLs)-producing Enterobacteriales 2
Alternative Treatment Options
Second-line options include:
- Oral cephalosporins such as cephalexin or cefixime
- Fluoroquinolones
- β-lactams, such as amoxicillin-clavulanate 2
Treatment of UTIs Caused by Resistant Organisms
Treatment options for UTIs caused by multidrug-resistant (MDR) organisms, including ESBLs-producing Enterobacteriales and carbapenem-resistant Enterobacteriales (CRE), include:
- Nitrofurantoin
- Fosfomycin
- Pivmecillinam
- Fluoroquinolones
- β-lactams, such as amoxicillin-clavulanate
- Carbapenems
- Ceftazidime-avibactam
- Cefiderocol 2