Complete dosing information for nitrofurantoin monohydrate/macrocrystals
Medical guidance required: Dosing information here is for educational purposes. Your healthcare provider will determine the appropriate dose based on your specific condition, kidney function, other medications, and medical history. Never adjust your dose without consulting your doctor or pharmacist.
Acute uncomplicated UTI (Macrobid 100 mg capsule): One 100 mg capsule twice daily (every 12 hours) for 5–7 days. Macrodantin 50–100 mg four times daily for 7 days. Long-term suppressive therapy (Macrodantin): 50–100 mg once daily at bedtime. Maximum dose: 400 mg/day. Dose adjustment required for renal impairment — contraindicated when CrCl <45 mL/min or serum creatinine >2 mg/dL.
Not approved for use in infants under 1 month of age due to risk of hemolytic anemia. Children over 1 month (Macrodantin suspension): 5–7 mg/kg/day in four divided doses; maximum 400 mg/day. Macrobid capsule formulation is generally used in patients who can swallow capsules. Safety and efficacy of Macrobid specifically have not been established in pediatric patients under 12 years.