From the Guidelines
For a urinary tract infection (UTI) in a patient with low estimated glomerular filtration rate (eGFR), the most appropriate antibiotic choice should be guided by local resistance patterns and urine culture results when available, with consideration of dose adjustments for renal impairment, as recommended by the European Association of Urology guidelines 1. When considering antibiotic options for a patient with low eGFR, it's essential to weigh the potential benefits and risks of each medication.
- Nitrofurantoin should be avoided if eGFR is below 30 ml/min due to the risk of crystalluria and neurotoxicity 1.
- Trimethoprim-sulfamethoxazole (TMP-SMX) requires dose adjustment, with a recommended reduction to half the dose when creatinine clearance is between 15-30 mL/min, as outlined in guidelines for managing chronic kidney disease 1.
- Cephalexin can be used, typically dosed at 500 mg twice daily for 7 days, with a reduction to 250 mg twice daily if eGFR is below 30 ml/min.
- Amoxicillin-clavulanate is another option, dosed at 500/125 mg twice daily, with a reduction to once daily for severe renal impairment.
- Fosfomycin is a viable alternative, given as a single 3-gram dose with minimal renal adjustment needed.
- For more severe infections, fluoroquinolones like ciprofloxacin can be used with appropriate dose reductions, such as 250-500 mg every 24 hours instead of every 12 hours when eGFR is below 30 ml/min, as suggested by guidelines for managing chronic kidney disease 1. It's crucial to monitor renal function during treatment, as some antibiotics can further impact kidney function, and to adjust the antibiotic regimen accordingly, based on the most recent and highest quality evidence available 1.
From the FDA Drug Label
Patients with impaired renal function do not generally require a reduction in dose unless the impairment is severe. Renal impairment patients with a glomerular filtration rate of <30 mL/min should not receive the 875 mg/125 mg dose Patients with a glomerular filtration rate of 10 to 30 mL/min should receive 500 mg/125 mg or 250 mg/125 mg every 12 hours, depending on the severity of the infection. Patients with a glomerular filtration rate less than 10 mL/min should receive 500 mg/125 mg or 250 mg/125 mg every 24 hours, depending on severity of the infection
For a patient with a low eGFR, amoxicillin-clavulanate dosing should be adjusted based on the severity of the renal impairment.
- For an eGFR of 10-30 mL/min, the recommended dose is 500 mg/125 mg or 250 mg/125 mg every 12 hours.
- For an eGFR less than 10 mL/min, the recommended dose is 500 mg/125 mg or 250 mg/125 mg every 24 hours 2.
From the Research
Antibiotic Options for UTI with Low eGFR
- For patients with low estimated glomerular filtration rate (eGFR), the choice of antibiotic for urinary tract infections (UTIs) is crucial 3, 4.
- Nitrofurantoin is a commonly used antibiotic for UTIs, but its effectiveness may be reduced in patients with low eGFR due to subtherapeutic urine concentrations 4.
- However, a study found that mild or moderate reductions in eGFR did not justify avoidance of nitrofurantoin 4.
- Other antibiotic options for UTIs in patients with low eGFR include:
- Amoxicillin-clavulanate, which has been shown to be effective in treating UTIs caused by extended-spectrum beta-lactamase (ESBL)-producing organisms 5, 6.
- Ciprofloxacin, which has been found to be one of the most effective treatments for UTIs in women 7.
- Fosfomycin, pivmecillinam, and fluoroquinolones, which are also recommended as first-line or second-line options for UTIs 3.
Considerations for Antibiotic Choice
- The choice of antibiotic should be based on the patient's renal function, as well as the susceptibility patterns of the causative organism 3.
- It is essential to use antibiotics wisely to avoid resistance development, especially in patients with low eGFR 3.
- The minimum inhibitory concentration (MIC) of the antibiotic should also be considered, as high MICs may be associated with resistance development and treatment failure 6.