From the Guidelines
Macrobid (Nitrofurantoin) is an effective treatment for Escherichia coli (E. coli) infections in patients with a urine culture positive for E. coli, with a recommended dosage of 100 mg twice daily for 5 days. According to the most recent guidelines from the European Association of Urology 1, nitrofurantoin is a first-line treatment option for uncomplicated cystitis in women. The guidelines suggest that nitrofurantoin macrocrystals or monohydrate can be used at a dose of 100 mg twice daily for 5 days.
Efficacy of Nitrofurantoin
The efficacy of nitrofurantoin against E. coli has been demonstrated in several studies, including a study published in the Clinical Infectious Diseases journal 1, which showed that nitrofurantoin monohydrate/macrocrystals had similar clinical cure rates to trimethoprim-sulfamethoxazole and ciprofloxacin. Another study 1 demonstrated that nitrofurantoin had a clinical cure rate of 88-93% and a bacterial cure rate of 81-92%.
Important Considerations
It's essential to note that while most E. coli strains are susceptible to nitrofurantoin, some may be resistant, so susceptibility testing is valuable when available 1. Additionally, nitrofurantoin should be taken with food to increase absorption and reduce stomach upset. Patients with significant kidney impairment (creatinine clearance <30 mL/min) should not use nitrofurantoin, and it's not recommended for systemic infections or prostatitis. Patients should complete the full course of antibiotics even if symptoms improve before completion.
Treatment Duration and Dosage
The recommended treatment duration for uncomplicated UTIs is typically 5 days, although shorter courses may be used in some cases 1. The standard dosage for uncomplicated UTIs is 100 mg twice daily, and nitrofurantoin should be taken with food to increase absorption and reduce stomach upset.
Resistance and Susceptibility
The European Association of Urology guidelines 1 recommend using nitrofurantoin as a first-line treatment option for uncomplicated cystitis in women, with the caveat that local resistance patterns should be considered. If the local resistance pattern for E. coli is <20%, cephalosporins (e.g., cefadroxil) can be used as an alternative treatment option.
Quality of Life and Morbidity
The use of nitrofurantoin to treat E. coli infections can improve quality of life by reducing symptoms and morbidity associated with urinary tract infections. By effectively treating the infection, patients can experience a reduction in symptoms such as dysuria, frequency, and urgency, and a decrease in the risk of complications such as pyelonephritis or sepsis.
From the Research
Effectiveness of Macrobid (Nitrofurantoin) against E. coli
- Macrobid (Nitrofurantoin) has been shown to be effective against Escherichia coli (E. coli) in several studies 2, 3, 4, 5.
- A study published in 2008 found that 95.6% of E. coli urine isolates were susceptible to nitrofurantoin, with an average 2.3% resistance rate 2.
- Another study published in 2015 noted that nitrofurantoin is a broad-spectrum bactericidal antibiotic that is effectively used to treat urinary tract infections (UTIs) caused by E. coli 3.
- A study published in 2016 found that the resistance rate of E. coli to nitrofurantoin was 0.9% 4.
- A study published in 2012 evaluated the effect of nitrofurantoin in the treatment of extended-spectrum β-lactamase (ESBL)-producing E. coli-related lower urinary tract infection (LUTI) and found that overall clinical and microbiological success rates were 69% and 68%, respectively 5.
Susceptibility of E. coli to Nitrofurantoin
- The studies suggest that E. coli is generally susceptible to nitrofurantoin, with low resistance rates 2, 3, 4, 5.
- The low resistance rate of E. coli to nitrofurantoin makes it a suitable treatment option for UTIs caused by this bacterium 2, 4.
- Nitrofurantoin has been shown to be effective against ESBL-producing E. coli, which are often resistant to other antibiotics 5.
Clinical Implications
- The effectiveness of nitrofurantoin against E. coli makes it a suitable treatment option for UTIs caused by this bacterium 2, 3, 4, 5.
- The low resistance rate of E. coli to nitrofurantoin suggests that it can be used as a first-line treatment for UTIs 2, 4.
- Nitrofurantoin may be an alternative treatment option for UTIs caused by ESBL-producing E. coli 5.