What antibiotic should be given to an elderly male patient with a urinary tract infection (UTI) who still has symptoms and a positive urinalysis (UA) despite being treated with cephalexin (cephalexin)?

From the Guidelines

For an elderly male patient with a persistent urinary tract infection despite cephalexin treatment, I recommend switching to a fluoroquinolone such as ciprofloxacin (500 mg twice daily for 7 days) or levofloxacin (750 mg once daily for 5 days), as these antibiotics have a broader spectrum of activity against common uropathogens, including ESBL-producing organisms 1. When considering alternative treatments, it's essential to take into account the patient's medication history and local resistance patterns. Trimethoprim-sulfamethoxazole (160/800 mg twice daily for 7 days) could be another effective option. However, the choice of antibiotic should be guided by the results of a urine culture and susceptibility testing, which should be performed to identify the specific pathogen and its antibiotic sensitivities 1. Key factors to consider in the management of this patient include:

• The possibility of a complicated UTI, which may require broader antibiotic coverage and treatment of any underlying urological abnormalities 1
• The need for urological evaluation, particularly if this represents a recurrent infection, as elderly men often have underlying conditions like prostatic hypertrophy or urinary retention that contribute to persistent infections
• The importance of monitoring renal function when prescribing these medications, as elderly patients may require dose adjustments based on their creatinine clearance
• The potential for antimicrobial resistance, which is more likely in complicated UTIs, and the need to tailor empiric therapy to local resistance patterns and specific host factors, such as allergies 1

From the Research

Alternative Antibiotic Options

Given that the elderly male patient still has symptoms and a positive urinalysis (UA) despite being treated with cephalexin, alternative antibiotic options should be considered. The following points outline potential alternatives:

• Amoxicillin-clavulanate may be a useful alternative therapy for the treatment of ceftriaxone non-susceptible Enterobacterales UTIs, as shown in a study published in 2024 2.
• Nitrofurantoin appears to be consistent with recommendations and demonstrates a favorable resistance profile for treatment of outpatient UTI, as suggested by a study published in 2022 3.
• Second and third generation cephalosporins may be acceptable options given resistance patterns, according to a study published in 2022 3.

Considerations for Antibiotic Selection

When selecting an alternative antibiotic, the following factors should be considered:

• Resistance patterns: The choice of antibiotic should be guided by local resistance patterns, as highlighted in a study published in 2022 3.
• Patient factors: The patient's medical history, allergies, and other health conditions should be taken into account when selecting an antibiotic.
• Antibiotic efficacy: The efficacy of different antibiotics for UTI treatment has been compared in several studies, including a network meta-analysis published in 2012 4.

Potential Next Steps

Based on the available evidence, potential next steps for the patient's treatment could include:

• Switching to amoxicillin-clavulanate or nitrofurantoin, considering the patient's specific situation and local resistance patterns.
• Consulting with an infectious disease specialist or a urologist to determine the best course of treatment.
• Re-evaluating the patient's symptoms and UA results to ensure that the alternative antibiotic is effective.