From the Guidelines
Keflex (cephalexin) is not the first-line treatment for uncomplicated urinary tract infections (UTIs) due to its inferior efficacy and higher resistance rates compared to other recommended agents, as stated in the 2011 guidelines by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases 1.
Treatment Recommendations
When considering treatment options for UTIs, it's essential to prioritize agents with minimal resistance and collateral damage. The following are recommended:
- Nitrofurantoin monohydrate/macrocrystals (100 mg twice daily for 5 days) is an appropriate choice for therapy due to minimal resistance and efficacy comparable to 3 days of trimethoprim-sulfamethoxazole 1.
- Trimethoprim-sulfamethoxazole (160/800 mg twice-daily for 3 days) is an appropriate choice for therapy, given its efficacy as assessed in numerous clinical trials, if local resistance rates of uropathogens causing acute uncomplicated cystitis do not exceed 20% or if the infecting strain is known to be susceptible 1.
Keflex (Cephalexin) Considerations
While Keflex (cephalexin) may be considered for UTI treatment in certain settings, its use should be cautious due to inferior efficacy and more adverse effects compared to other UTI antimicrobials 1. The 2024 European Association of Urology guidelines do not specifically recommend Keflex as a first-line treatment for complicated UTIs, instead suggesting a combination of amoxicillin plus an aminoglycoside or a second-generation cephalosporin plus an aminoglycoside 1.
Patient Considerations
It's crucial to inform your healthcare provider about any penicillin allergy, as there's potential for cross-reactivity with Keflex. Additionally, patients should drink plenty of water to help flush bacteria from the urinary tract and contact their doctor if symptoms don't improve within a few days or if they worsen. Common side effects may include diarrhea, nausea, and stomach pain, and Keflex should be taken with food if it causes stomach upset.
From the FDA Drug Label
Genitourinary tract infections, including acute prostatitis, caused by Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae Cephalexin is indicated for the treatment of genitourinary tract infections caused by susceptible strains of Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae 2. Key points:
- Cephalexin is effective against certain bacteria that cause UTIs
- It is essential to perform culture and susceptibility tests to ensure the bacteria are susceptible to cephalexin
- Cephalexin should only be used to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria 2
From the Research
Keflex Treatment for UTI
- Keflex, also known as cephalexin, is a first-generation oral cephalosporin that has been traditionally considered a second-line treatment option for uncomplicated lower urinary tract infections (uLUTIs) 3.
- However, due to the increasing resistance of Enterobacteriaceae, there is a need to rethink the use of available antibiotic armamentarium, and cephalexin may be a viable option for the treatment of uLUTIs 3.
- Cephalexin has been shown to have good early bacteriological and clinical cures in uLUTIs due to non-extended-spectrum beta-lactamase-producing (ESBL) Enterobacteriaceae, comparable to many traditionally first-line agents 3.
- The recommended dosage of cephalexin for the treatment of UTIs is 500 mg twice or thrice daily 3.
Comparison with Other Antibiotics
- Cephalexin may be a suitable alternative to fluoroquinolones, which have been associated with high rates of resistance and adverse events 3, 4.
- Nitrofurantoin, trimethoprim-sulfamethoxazole, and fosfomycin are recommended as first-line antibiotic treatments for uncomplicated UTIs, while cephalexin is considered a second-line option 5, 6, 4.
- However, cephalexin may be a more practical choice for many clinicians due to its convenient dosing schedule and available antimicrobial susceptibility test interpretative criteria 3.
Resistance and Guideline Concordance
- The use of cephalexin for the treatment of UTIs may help reduce the risk of antibiotic resistance, as it is less commonly used than other antibiotics such as fluoroquinolones 3, 4.
- Guideline concordance for the treatment of uncomplicated UTIs is improving, but there is still a need for education and feedback on prescription habits to increase the use of first-line antibiotic agents and reduce the use of fluoroquinolones 4.