What is the dose of Macrobid (Nitrofurantoin) for Urinary Tract Infection (UTI)?

From the Guidelines

The standard dose of Macrobid (nitrofurantoin) for uncomplicated urinary tract infections (UTIs) in adults is 100 mg taken orally twice daily for 5 days. This regimen is typically effective for most uncomplicated lower UTIs, as supported by the most recent guidelines from the American College of Physicians 1. Macrobid should be taken with food to increase absorption and reduce gastrointestinal side effects. It's essential to complete the full course of antibiotics even if symptoms improve. Macrobid is effective for UTIs because it concentrates in the urinary tract and has broad-spectrum activity against many common uropathogens, including Escherichia coli, which accounts for more than 75% of all bacterial cystitis 1. However, it should not be used in patients with creatinine clearance below 60 mL/min or in those with upper UTIs or pyelonephritis. Patients should be advised to stay well-hydrated during treatment. If symptoms persist or worsen after completing the course, they should consult their healthcare provider for reevaluation. The Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases also recommend nitrofurantoin as an appropriate choice for therapy due to minimal resistance and propensity for collateral damage, with efficacy comparable to 3 days of trimethoprim-sulfamethoxazole 1.

Some key points to consider when prescribing Macrobid include:

• The importance of completing the full 5-day course of treatment to ensure effective eradication of the infection
• The need to advise patients to stay well-hydrated during treatment to help prevent recurrence of UTIs
• The potential for gastrointestinal side effects, which can be mitigated by taking the medication with food
• The contraindication in patients with creatinine clearance below 60 mL/min or in those with upper UTIs or pyelonephritis, as these conditions may require alternative treatment approaches.

Overall, the recommended dose of Macrobid for uncomplicated UTIs is supported by the most recent and highest-quality evidence, and its use should be guided by careful consideration of the patient's individual needs and medical history.

From the Research

Dose of Macrobid (Nitrofurantoin) for Urinary Tract Infection (UTI)

• The recommended dose of Macrobid (Nitrofurantoin) for UTI varies, but common regimens include:
  • 100 mg twice daily for 5-7 days 2
  • 100 mg twice daily for 7 days 3
• A 5-day course of nitrofurantoin is also recommended as first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 4
• However, some guidelines recommend a 3-day course of nitrofurantoin at 100 mg twice daily as first-line treatment for uncomplicated UTI, although the evidence base for this is limited 5

Considerations for Treatment

• The choice of agent for treating uncomplicated UTIs should be based on the pharmacokinetic characteristics of the molecule to optimize clinical benefit and minimize the risk of antibacterial resistance 6
• Nitrofurantoin shows good efficacy against most bacteria expected in urinary tract infection, and the development of resistance is low 3
• Urinary nitrofurantoin concentrations were mostly above minimum inhibitory concentrations of the isolated uropathogens, indicating effective treatment 3