From the Guidelines
Keflex (cephalexin) should not be the first-line treatment for uncomplicated urinary tract infections (UTIs) due to its inferior efficacy and higher propensity for adverse effects compared to other recommended agents, as stated in the 2010 update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases 1. When considering treatment options for UTIs, it's essential to prioritize agents with minimal resistance and collateral damage. According to the guidelines, nitrofurantoin monohydrate/macrocrystals, trimethoprim-sulfamethoxazole, and fosfomycin trometamol are preferred choices due to their efficacy and lower resistance rates 1. Some key points to consider when treating UTIs include:
- 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.
- Fosfomycin trometamol (3 g in a single dose) is an appropriate choice for therapy where it is available due to minimal resistance and propensity for collateral damage, but it appears to have inferior efficacy compared with standard short-course regimens 1. In general, beta-lactam agents like Keflex should be used with caution for uncomplicated cystitis due to their inferior efficacy and more adverse effects compared to other UTI antimicrobials 1.
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, including those caused by Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae 2. Key points:
- Cephalexin is effective against certain strains of 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 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, cephalexin may be reconsidered as a treatment option for 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 uLUTIs is 500 mg twice or thrice daily 3.
Comparison with Other Antibiotics
- Cephalexin may be used as a fluoroquinolone-sparing alternative for the treatment of uLUTIs 3.
- Nitrofurantoin, trimethoprim-sulfamethoxazole, and fosfomycin are recommended as first-line antibiotic treatments for uncomplicated urinary tract infections (UTIs) 4, 5, 6.
- Fluoroquinolones are not recommended as first-line treatments due to high rates of resistance and adverse events 4, 5, 6.
Guideline Concordance
- The overall concordance rate with Infectious Diseases Society of America guidelines for the treatment of uncomplicated UTIs in women was 58.4% 6.
- The use of fluoroquinolones decreased from 2015 to 2019, while the use of nitrofurantoin and beta-lactams increased 6.
- Obstetricians-gynecologists and urologists had a higher likelihood of concordant treatment than other specialties combined 6.