From the Guidelines
For a 76-year-old female with a urinary tract infection who has allergies to penicillins and sulfa drugs, nitrofurantoin (Macrobid) 100 mg twice daily for 5 days is the most appropriate first-line treatment option, as recommended by the American College of Physicians in 2021 1. This recommendation is based on the best practice advice for the treatment of uncomplicated bacterial cystitis, which suggests that nitrofurantoin for 5 days is a suitable option.
- The patient's allergies to penicillins and sulfa drugs make other commonly used antibiotics, such as trimethoprim-sulfamethoxazole, unsuitable.
- Fosfomycin (Monurol) 3 grams as a single dose could be considered as an alternative, but it is not the first-line option according to the most recent guidelines 1.
- Fluoroquinolones, such as ciprofloxacin, may be effective but should be used cautiously in the elderly due to the increased risk of tendon rupture and CNS effects.
- It is essential to assess the patient's renal function before prescribing nitrofurantoin, as it is contraindicated if creatinine clearance is below 30 ml/min.
- The patient should complete the full course of antibiotics, even if symptoms improve quickly, and return for follow-up if symptoms persist or worsen after 48-72 hours of treatment. The American College of Physicians' guidelines 1 prioritize the use of nitrofurantoin for 5 days as a first-line treatment for uncomplicated bacterial cystitis, making it the most suitable option for this patient.
From the FDA Drug Label
The following in vitro data are available, but their clinical significance is unknown: Levofloxacin exhibits in vitro minimum inhibitory concentrations (MIC values) of 2 mcg/mL or less against most (≥ 90%) isolates of the following microorganisms; however, the safety and effectiveness of levofloxacin in treating clinical infections due to these bacteria have not been established in adequate and well-controlled clinical trials Gram-Negative Bacteria Escherichia coli Klebsiella pneumoniae Proteus mirabilis Pseudomonas aeruginosa
Levofloxacin can be used to treat urinary tract infections caused by Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa.
- The patient is allergic to penicillins and sulfa drugs, but levofloxacin is a fluoroquinolone, which is a different class of antibiotics.
- Levofloxacin may be effective against the bacteria causing the urinary tract infection, but the patient's age (76 years old) and potential renal impairment should be considered when prescribing this medication 2.
- The dosage of levofloxacin may need to be adjusted based on the patient's renal function 2.
- The patient should be monitored for potential side effects, such as tendinitis or tendon rupture, which are more common in elderly patients 2.
From the Research
Treatment Options for Urinary Tract Infections
Given the patient's allergies to penicillins and sulfa drugs, alternative antibiotic options must be considered. The following treatment options are available for urinary tract infections (UTIs):
- Nitrofurantoin: a recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 3
- Fosfomycin tromethamine: a recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 3
- Pivmecillinam: a recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 3
- Fluoroquinolones: may be used as an alternative, but their use is discouraged due to high rates of resistance and adverse events 4, 5
- Cephalosporins: such as cephalexin or cefixime, may be used as a second-line option 3
- Amoxicillin-clavulanate: may be used as a second-line option, but its use is limited due to the patient's allergy to penicillins
Considerations for Older Adults
When treating UTIs in older adults, it is essential to consider the increased risk of misdiagnosis and inappropriate antibiotic therapy 6. Accurate diagnosis and effective evidence-based treatment are crucial in this population, and specific guidelines for UTI in older people are needed.
Resistance Patterns and Treatment Failure
The growing problem of antibiotic resistance and treatment failure due to resistance to commonly used antibiotics must be considered when selecting a treatment option 3, 7. The use of targeted therapy, emphasizing the correct antibacterial spectrum and pharmacodynamic superiority, is likely to provide important benefits, such as reduced morbidity and associated costs, and reduced emergence of resistance 7.