From the Research
For treating Enterococcus faecalis infections with Macrobid (nitrofurantoin), the typical dosage is 100 mg taken orally twice daily for 5-7 days for uncomplicated urinary tract infections, as supported by the most recent study 1.
Treatment Considerations
- The treatment duration may be extended to 7-14 days for complicated infections.
- Macrobid should be taken with food to improve absorption and reduce gastrointestinal side effects.
- It's essential to note that nitrofurantoin is primarily effective for lower urinary tract infections, as it concentrates in the urine, making it suitable for E. faecalis cystitis but not for systemic infections.
- Patients should complete the full course of treatment even if symptoms improve before completion.
- Nitrofurantoin works by damaging bacterial DNA and inhibiting protein synthesis, and it generally has good activity against E. faecalis in the urinary tract, as shown in a study from 2020 1.
Important Considerations
- However, susceptibility testing is recommended as resistance can occur, with a study from 2004 showing that 12% of E. faecalis strains were resistant to nitrofurantoin 2.
- The medication is contraindicated in patients with significant renal impairment (creatinine clearance <30 mL/min) as it won't achieve adequate urinary concentrations and may increase toxicity risk.
- A study from 2020 found that nitrofurantoin was still active in vitro against urinary isolates of multidrug-resistant enterococci, including vancomycin-resistant enterococci (VRE) 1.
Key Points
- The most recent study from 2020 1 provides the strongest evidence for the use of nitrofurantoin in treating E. faecalis infections.
- Fosfomycin may be a potential alternative for treating multidrug-resistant E. faecalis, as shown in the same study 1.
- It's crucial to consider the potential for resistance and the importance of susceptibility testing when treating E. faecalis infections with nitrofurantoin.