What is the recommended dose of Macrobid (nitrofurantoin) for an uncomplicated urinary tract infection (UTI)?

Recommended Macrobid (Nitrofurantoin) Dosing for Uncomplicated UTI

For uncomplicated urinary tract infections, the recommended dose of Macrobid (nitrofurantoin monohydrate/macrocrystals) is 100 mg twice daily for 5 days. 1, 2, 3

First-line Treatment Options for Uncomplicated UTI

• Nitrofurantoin is considered a first-line treatment for uncomplicated cystitis in women according to both European and American guidelines 1, 2, 3
• Available formulations include:
  • Nitrofurantoin monohydrate/macrocrystals (Macrobid): 100 mg twice daily for 5 days 3
  • Nitrofurantoin macrocrystals: 50-100 mg four times daily for 5 days 1
  • Nitrofurantoin macrocrystals prolonged release: 100 mg twice daily for 5 days 1

Efficacy Data

• Clinical cure rates with nitrofurantoin range from 88-93% for uncomplicated UTIs 2, 3
• Bacterial cure rates range from 81-92% 3
• A 5-day course of nitrofurantoin has been shown to be more effective than single-dose fosfomycin, with clinical resolution rates of 70% vs 58% respectively 4

Important Considerations and Contraindications

• Renal function requirement: Nitrofurantoin is contraindicated in patients with creatinine clearance <60 mL/min due to inadequate urinary drug concentrations and increased risk of toxicity 2
• For patients with impaired renal function, alternative agents such as trimethoprim-sulfamethoxazole or fosfomycin should be considered 2
• Common side effects include nausea and headache 3

Treatment Duration Considerations

• The 5-day regimen is the most widely recommended duration for nitrofurantoin in uncomplicated UTIs 1, 3
• While some UK guidelines have suggested 3-day courses, there is limited direct evidence supporting shorter courses for nitrofurantoin specifically 5
• The European Association of Urology guidelines specifically recommend a 5-day course 1

Alternative First-line Options

• Other first-line options for uncomplicated UTI include:
  • Fosfomycin trometamol: 3 g single dose 1
  • Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 3 days (if local E. coli resistance is <20%) 1, 6

Follow-up Recommendations

• Routine post-treatment urinalysis or urine cultures are not indicated for asymptomatic patients 1
• For women whose symptoms do not resolve by the end of treatment or recur within 2 weeks, a urine culture with susceptibility testing should be performed 1
• Retreatment with a 7-day regimen using another agent should be considered if symptoms persist or recur 1