Nitrofurantoin (Macrobid) Use in Children
Yes, Macrobid (nitrofurantoin) can be safely given to children for urinary tract infections, but it should not be used in infants under 1 month of age due to the risk of hemolytic anemia.
Indications and Age Considerations
Nitrofurantoin is an effective antibiotic for treating lower urinary tract infections (cystitis) in pediatric patients, particularly those caused by susceptible organisms including ESBL-producing E. coli 1. However, there are important age restrictions:
- Contraindicated in infants <1 month of age due to risk of hemolytic anemia
- Safe and effective in children >1 month of age with normal renal function
- Particularly useful for UTIs caused by multi-drug resistant organisms
Dosing Guidelines
The appropriate dosing of nitrofurantoin in children is weight-based:
- Therapeutic dosing: 5-7 mg/kg/day divided into 4 doses (every 6 hours)
- Maximum daily dose: 400 mg/day
- Prophylactic dosing: 1-2 mg/kg given once daily (usually at bedtime)
- Duration: Typically 5-7 days for uncomplicated UTIs
Clinical Efficacy
Nitrofurantoin has demonstrated excellent clinical efficacy in pediatric populations:
- 98% bacteriological response rate in children with lower UTIs caused by ESBL-producing E. coli 1
- High susceptibility rates against common uropathogens, including many multi-drug resistant strains 2
- Low resistance rates compared to other commonly used antibiotics for UTIs
Precautions and Contraindications
Several important precautions should be observed when prescribing nitrofurantoin to children:
- Renal function: Avoid in patients with significant renal impairment (creatinine clearance <60 mL/min) as the drug may not achieve adequate urinary concentrations
- Pulmonary reactions: Monitor for signs of acute pulmonary toxicity (cough, dyspnea, chest pain) 3
- G6PD deficiency: Use with caution in patients with G6PD deficiency due to risk of hemolysis
- Duration: Long-term use should be avoided when possible due to risk of chronic pulmonary reactions
Administration Considerations
For optimal efficacy and tolerability:
- Administer with food to improve absorption and reduce gastrointestinal side effects
- Ensure adequate fluid intake throughout treatment
- Complete the full course of therapy even if symptoms improve quickly
- Available in liquid suspension for children who cannot swallow tablets
Monitoring
When administering nitrofurantoin to children, monitor for:
- Gastrointestinal effects: Nausea, vomiting, diarrhea (most common side effects)
- Respiratory symptoms: New onset cough, dyspnea, or chest pain
- Neurological effects: Headache, dizziness
- Allergic reactions: Rash, urticaria, pruritus
Clinical Pearls
- Nitrofurantoin is concentrated in the urine, making it ideal for lower UTIs but ineffective for pyelonephritis or systemic infections
- The medication may cause a harmless brown discoloration of the urine
- Nitrofurantoin has maintained good efficacy against uropathogens despite decades of use 2
- Consider nitrofurantoin as a first-line option for uncomplicated UTIs in children to spare broader-spectrum antibiotics
By following these guidelines, nitrofurantoin (Macrobid) can be safely and effectively used in the pediatric population for appropriate indications.