From the Guidelines
Macrobid (nitrofurantoin) is recommended for the treatment of uncomplicated urinary tract infections due to Enterococcus faecalis, but its effectiveness against Enterococcus faecium is variable and often resistant, as noted in studies 1. The typical dosage for Macrobid is 100 mg taken orally twice daily for 5-7 days for uncomplicated UTIs.
- It's essential to note that Macrobid is only effective for lower urinary tract infections as it concentrates in the urine and doesn't achieve adequate tissue levels for treating systemic infections.
- Macrobid works by damaging bacterial DNA after being reduced by bacterial enzymes, and it has maintained good efficacy against many urinary pathogens including E. faecalis despite decades of use.
- Before starting treatment, kidney function should be assessed as the drug is contraindicated in patients with creatinine clearance below 60 ml/min due to reduced efficacy and increased risk of toxicity.
- For complicated UTIs, pyelonephritis, or systemic enterococcal infections, alternative antibiotics with better tissue penetration, such as linezolid or daptomycin, would be more appropriate, as recommended in studies 1. Some key points to consider when treating enterococcal infections include:
- Differentiating colonization from true infection prior to empiric prescription of anti-VRE antimicrobial agents, as emphasized in study 1.
- The importance of monitoring creatinine kinase levels when using high-dose daptomycin, as noted in study 1.
- The potential benefits of combination antimicrobial therapy in severely ill patients or those who fail treatment with traditional options, as discussed in study 1.
From the Research
Macrobid Coverage for Enterococcus
- Macrobid, also known as nitrofurantoin, is an antibiotic used to treat urinary tract infections (UTIs) 2.
- Studies have shown that nitrofurantoin is effective against enterococcal UTIs, including vancomycin-resistant enterococci (VRE) 2.
- In one study, 80.76% of VRE isolates were susceptible to nitrofurantoin 2.
- Another study found that nitrofurantoin was effective against Enterococcus faecalis and Enterococcus faecium, with susceptibility rates of 80.32% and 88.8%, respectively 2.
Comparison with Other Antibiotics
- Nitrofurantoin has been compared to other antibiotics, such as nitroxoline, in terms of its effectiveness against UTIs 3.
- One study found that nitroxoline had a broader antimicrobial spectrum than nitrofurantoin, but nitrofurantoin was still effective against most organisms 3.
- Another study compared aminopenicillins (APs) to non-aminopenicillins (NAPs) for the treatment of enterococcal lower UTIs, and found that APs were non-inferior to NAPs 4.
Clinical Implications
- The effectiveness of nitrofurantoin against enterococcal UTIs makes it a potential treatment option for patients with these infections [(2,5,6)].
- However, the choice of antibiotic should be based on individual patient factors, such as the severity of the infection and the presence of any underlying medical conditions 6.
- Further studies are needed to fully understand the effectiveness of nitrofurantoin against enterococcal UTIs and to determine the optimal treatment duration 6.