What is the dose and frequency of Macrobid (Nitrofurantoin)?

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Last updated: February 16, 2025View editorial policy

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From the Guidelines

The recommended dose and frequency of Macrobid (nitrofurantoin monohydrate) for the treatment of acute uncomplicated urinary tract infections is 100 mg twice daily for 5 days 1. For the treatment of acute uncomplicated pyelonephritis, the recommended dose is 100 mg twice daily for 7 to 10 days. The maximum daily dose should not exceed 200 mg.

Key Considerations

  • The choice of antibiotic should be based on local resistance patterns and patient-specific factors, such as allergy history and tolerance 1.
  • Nitrofurantoin monohydrate/macrocrystals is an appropriate choice for therapy due to minimal resistance and propensity for collateral damage, with efficacy comparable to 3 days of trimethoprim-sulfamethoxazole 1.
  • The fluoroquinolones, ofloxacin, ciprofloxacin, and levofloxacin, are highly efficacious in 3-day regimens but have a propensity for collateral damage and should be reserved for important uses other than acute cystitis 1.

Important Notes

  • The threshold of 20% as the resistance prevalence at which the agent is no longer recommended for empirical treatment of acute cystitis is based on expert opinion derived from clinical, in vitro, and mathematical modeling studies 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. Some key points to consider when prescribing Macrobid (nitrofurantoin monohydrate) include:
  • Patient allergy history and tolerance
  • Local resistance patterns
  • Availability of alternative antibiotics
  • Patient-specific factors, such as pregnancy or breastfeeding status It is essential to weigh the benefits and risks of each antibiotic option and consider patient-specific factors when making a treatment decision 1.

From the Research

Dose and Frequency of Macrobid (Nitrofurantoin)

  • The dose and frequency of Macrobid (Nitrofurantoin) can vary depending on the specific treatment regimen and patient population.
  • According to a study published in JAMA in 2014 2, nitrofurantoin monohydrate/macrocrystals (100 mg twice daily for 5-7 days) is an appropriate first-line therapy for uncomplicated cystitis.
  • A study published in Medizinische Klinik in 2010 3 used a dose of 100 mg twice daily for 7 days to treat acute lower urinary tract infections in adults, with a microbial eradication rate of 92.3% at 12 to 16 days after baseline.
  • Another study published in Clinical microbiology and infection in 2022 4 compared the effectiveness and safety of 50 mg and 100 mg daily prophylaxis with nitrofurantoin for recurrent urinary tract infections, and found that 50 mg daily was associated with a lower hazard of adverse events.
  • A review published in Drug resistance updates in 2019 5 noted that the dose justification for nitrofurantoin is not well established, and that pharmacokinetic and pharmacodynamic data are needed to optimize dosing regimens.
  • An older study published in Pharmacy world & science in 1993 6 compared a single dose of 3 g fosfomycin trometamol with 7 days of nitrofurantoin 50 mg four times daily, and found that the clinical and bacteriological cure rates were not significantly different between the treatment groups.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Nitrofurantoin 100 mg versus 50 mg prophylaxis for urinary tract infections, a cohort study.

Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases, 2022

Research

Optimizing dosing of nitrofurantoin from a PK/PD point of view: What do we need to know?

Drug resistance updates : reviews and commentaries in antimicrobial and anticancer chemotherapy, 2019

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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