From the Research
Roxithromycin is not effective against E. coli infections and should not be used as a first-line treatment for these infections. E. coli is a gram-negative bacterium that typically has intrinsic resistance to macrolide antibiotics like roxithromycin due to its outer membrane structure, which prevents the drug from reaching its target site within the bacterial cell. Macrolides primarily work by binding to the 50S subunit of the bacterial ribosome to inhibit protein synthesis, but they cannot easily penetrate the outer membrane of gram-negative organisms.
Key Points to Consider
- For E. coli infections, more appropriate antibiotic choices would include fluoroquinolones (such as ciprofloxacin), trimethoprim-sulfamethoxazole, nitrofurantoin, or beta-lactams (like cephalosporins or amoxicillin-clavulanate), depending on the site of infection and local resistance patterns 1.
- Treatment selection should be guided by susceptibility testing whenever possible, as E. coli resistance to various antibiotics is increasingly common worldwide.
- If you suspect an E. coli infection, consult with a healthcare provider for proper diagnosis and appropriate antibiotic selection.
Additional Considerations
- The use of fluoroquinolones, such as ciprofloxacin, may be limited due to increasing resistance rates, as seen in a study from 2008, which found that E. coli uropathogens had a mean 75.6% and 75.9% susceptibility and 24.2% and 24% resistance rate to both ciprofloxacin and levofloxacin, respectively 2.
- Nitrofurantoin is a good alternative, with a study from 2022 showing that it is effective against E. coli, with a mean susceptibility rate of 95.6% 3.
- Another study from 2021 found that guideline discordance continues in the treatment of uncomplicated urinary tract infections, with the overuse of fluoroquinolones and the underuse of first-line antibiotic agents, such as nitrofurantoin and beta-lactams 4.
- A study from 2020 compared oral β-lactam antibiotics with fluoroquinolones or trimethoprim-sulfamethoxazole for the definitive treatment of Enterobacterales bacteremia from a urine source, and found that oral β-lactam antibiotics may be a reasonable step-down treatment option, primarily when alternative options are limited by resistance or adverse effects 5.