Nitrofurantoin is specifically indicated for the treatment & prophylaxis of urinary tract infections when due to susceptible strains of Escherichia coli, Enterococci, Staphylococcus aureus, Staphylococcus saprophyticus and certain susceptible strains of Klebsiella and Enterobacter species.

Dosage: 

• Adults: 50-100 mg four times a day - the lower dosage level is recommended for uncomplicated urinary tract infections.
• Children: 5-7 mg/kg/day in four divided doses (contraindicated under one month of age). Therapy should be continued for one week or for at least 3 days after sterility of the urine is obtained. 
• For long-term suppressive therapy in adults: a reduction of dosage to 50-100 mg at bedtime may be adequate. For long-term suppressive therapy in children, doses as low as 1 mg/kg per 24 hours, given in a single dose or in two divided doses, may be adequate.

Side effects: The most frequent clinical adverse events are nausea, headache, and flatulence. Other less occurred adverse events are diarrhea, dyspepsia, abdominal pain, constipation, emesis, dizziness, drowsiness