Should a 67-year-old female with a recent diagnosis of Urinary Tract Infection (UTI) at the University Campus (UC) be retreated with antibiotics, such as Macrobid (Nitrofurantoin), given that her symptoms have partially improved after a 5-day course, but she continues to experience back pain and bladder spasms without fever?

From the Guidelines

The patient should be evaluated by a healthcare provider before starting another course of antibiotics, and the provider may recommend completing a longer course of Macrobid (typically 7 days total), switching to a different antibiotic based on culture results, or ordering additional tests to rule out kidney involvement. While some improvement after 5 days of Macrobid (nitrofurantoin) is encouraging, persistent back pain and bladder spasms could indicate that the infection hasn't fully resolved or that there might be a more complicated issue like pyelonephritis (kidney infection) 1. The provider may consider ordering a urine culture and sensitivity, urinalysis, or imaging studies to rule out kidney involvement. Back pain specifically raises concern for possible kidney infection, which would require a different antibiotic regimen, typically a fluoroquinolone like ciprofloxacin 500mg twice daily for 7 days or trimethoprim-sulfamethoxazole DS twice daily for 14 days 1. The absence of fever is reassuring but doesn't rule out a more serious infection. In the meantime, the patient should:

• Increase fluid intake
• Avoid bladder irritants like caffeine and alcohol
• Use over-the-counter pain relievers like phenazopyridine (AZO) for symptom relief while awaiting medical evaluation It's also important to note that the European Association of Urology guidelines recommend that patients with uncomplicated pyelonephritis should be treated with fluoroquinolones or cephalosporins, and that other agents like nitrofurantoin should be avoided due to insufficient data on their efficacy 1. Additionally, the guidelines suggest that treatment duration should be tailored to the individual patient, but typically ranges from 7 to 14 days 1.

From the Research

Treatment of Uncomplicated Urinary Tract Infection (UTI)

• The patient has completed 5 days of Macrobid (nitrofurantoin) and still experiences back pain and bladder spasms, but no fever.
• According to the study 2, nitrofurantoin is a good fluoroquinolone-sparing alternative and has a low resistance rate of 2.3%, making it an acceptable treatment for uncomplicated UTIs.
• The study 3 compared the clinical and microbiologic efficacy of nitrofurantoin and fosfomycin in women with uncomplicated cystitis, and found that 5-day nitrofurantoin resulted in a significantly greater likelihood of clinical and microbiologic resolution at 28 days after therapy completion.

Considerations for Retreatment

• The study 4 found that prior cultures had good predictive value for detecting future susceptibility to first-line agents, including nitrofurantoin.
• However, the study 5 suggested that the soxRS regulon of Escherichia coli, a superoxide-defense system, may be involved in antibiotic multi-resistance, and that nitrofurantoin and phenazopyridine may interact with this system.
• The review 6 concluded that nitrofurantoin can be considered the most effective drug in the treatment of acute urinary infection, but highlighted the importance of considering long-term side effects, especially in elderly patients.

Potential Next Steps

• Consider obtaining a urine culture to guide further treatment and determine the susceptibility of the uropathogen to nitrofurantoin or other antibiotics 4.
• Evaluate the patient's symptoms and medical history to determine if a longer course of nitrofurantoin or an alternative antibiotic is necessary 3, 6.
• Monitor the patient for potential side effects of nitrofurantoin, especially if retreatment is considered 5, 6.