From the Guidelines
For an 87-year-old woman with a UTI who is allergic to Bactrim and has a CrCl of 54, I recommend nitrofurantoin (Macrobid) 100 mg orally twice daily for 5 days as the first-line treatment. This recommendation is based on the guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women, which suggest that nitrofurantoin monohydrate/macrocrystals is an appropriate choice for therapy due to minimal resistance and propensity for collateral damage 1. The patient's creatinine clearance of 54 ml/min indicates moderate renal impairment but is still adequate for nitrofurantoin use, as it is contraindicated when CrCl <30 ml/min.
Some key points to consider when treating UTIs in elderly patients include:
- Ensuring adequate hydration
- Monitoring for medication side effects
- Following up to confirm resolution of symptoms
- Considering the potential for increased risk of adverse effects with certain antibiotics, such as fluoroquinolones, in elderly patients
Nitrofurantoin is preferred because it achieves high urinary concentrations, has limited resistance patterns, and causes minimal disruption to gut flora compared to broader-spectrum antibiotics 1. Alternatively, cephalexin 500 mg orally four times daily for 7 days could be considered, but fluoroquinolones like ciprofloxacin should be reserved as a third option due to the increased risk of adverse effects in elderly patients. The guidelines also suggest that the choice of antibiotic should be individualized and based on patient allergy and compliance history, local practice patterns, local community resistance prevalence, availability, cost, and patient and provider threshold for failure 1.
In terms of efficacy, nitrofurantoin has been shown to have similar clinical cure rates to other antibiotics, such as trimethoprim-sulfamethoxazole and ciprofloxacin, and is superior to placebo treatment of women with acute cystitis 1. Overall, nitrofurantoin is a safe and effective option for the treatment of UTIs in elderly patients with moderate renal impairment.
From the FDA Drug Label
Geriatric patients are at increased risk for developing severe tendon disorders including tendon rupture when being treated with a fluoroquinolone such as levofloxacin. The pharmacokinetic properties of levofloxacin in younger adults and elderly adults do not differ significantly when creatinine clearance is taken into consideration. However, since the drug is known to be substantially excreted by the kidney, the risk of toxic reactions to this drug may be greater in patients with impaired renal function Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function
The first line treatment for a UTI in an 87-year-old woman with a CrCl of 54 who is allergic to Bactrim would likely be a fluoroquinolone. However, given the patient's age and renal impairment, caution should be exercised when prescribing levofloxacin or ciprofloxacin due to the increased risk of tendon disorders and toxic reactions.
- Levofloxacin dose adjustment is required for patients with CrCl < 50 mL/min.
- Ciprofloxacin dose adjustment is not explicitly stated for patients with CrCl > 50 mL/min, but caution is advised due to the potential for adverse reactions. Given the patient's CrCl of 54, which is close to the threshold for dose adjustment, and considering the potential risks, a conservative approach would be to choose an alternative antibiotic that is not a fluoroquinolone, or to closely monitor the patient's renal function and adjust the dose accordingly 2, 3.
From the Research
Treatment Options for UTI
Given the patient's allergy to Bactrim and a CrCl of 54, the following treatment options can be considered:
- Nitrofurantoin: a commonly recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis 4, 5, 6, 7
- Fosfomycin: a recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis 4, 5, 7
- Pivmecillinam: a recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis 4
- Oral cephalosporins such as cephalexin or cefixime: second-line options for UTI treatment 4
- Fluoroquinolones: second-line options for UTI treatment, but resistance rates should be considered 4, 5, 6, 7
- β-lactams such as amoxicillin-clavulanate: second-line options for UTI treatment 4, 7
Considerations for Renal Impairment
When considering treatment options for a patient with a CrCl of 54, it is essential to take into account the pharmacokinetic characteristics of the chosen antibiotic to minimize the risk of adverse effects and optimize clinical benefit 7.
- Nitrofurantoin: may not be suitable for patients with significant renal impairment, as it is primarily excreted by the kidneys 8
- Fosfomycin: can be used in patients with renal impairment, but dose adjustments may be necessary 7
Resistance Patterns
It is crucial to consider local resistance patterns when selecting an antibiotic for UTI treatment 4, 5, 6.