Nitrofurantoin Macrocrystals
Also sold as nitrofurantoin macrocrystals, Nitrofurantoin Macrocrystals
Medicine summary · from official FDA labels · Oct 19, 2026
What it’s used for
Nitrofurantoin capsules (macrocrystals) are specifically indicated for the treatment of urinary tract infections when due to susceptible strains of Escherichia coli , enterococci, Staphylococcus aureus , and certain susceptible strains of Klebsiella and Enterobacter species. Nitrofurantoin is not indicated for the treatment of pyelonephritis or perinephric abscesses.
How to take it
Nitrofurantoin capsules, (macrocrystals) should be given with food to improve drug absorption and, in some patients, tolerance. Adults: 50 mg to 100 mg four times a day - the lower dosage level is recommended for uncomplicated urinary tract infections.
Important warnings
Pulmonary reactions: ACUTE, SUBACUTE, OR CHRONIC PULMONARY REACTIONS HAVE BEEN OBSERVED IN PATIENTS TREATED WITH NITROFURANTOIN. IF THESE REACTIONS OCCUR, NITROFURANTOIN CAPSULES (MACROCRYSTALS) SHOULD BE DISCONTINUED AND APPROPRIATE MEASURES TAKEN.
Common side effects
Respiratory: CHRONIC, SUBACUTE, OR ACUTE PULMONARY HYPERSENSITIVITY REACTIONS MAY OCCUR. CHRONIC PULMONARY REACTIONS OCCUR GENERALLY IN PATIENTS WHO HAVE RECEIVED CONTINUOUS TREATMENT FOR SIX MONTHS OR LONGER.
Forms & strengths
25 MG / 75 MG Oral Capsule · 100 MG Oral Capsule · 100 MG Oral Tablet · 5 MG/ML Oral Suspension · 50 MG Oral Tablet · 25 MG Oral Capsule · 50 MG Oral Capsule · 10 MG/ML Oral Suspension
Questions to ask your doctor or pharmacist
- Is this the right medicine for my condition, and how long should I take it?
- What side effects should I watch for, and which need urgent attention?
- Does this interact with my other medicines, supplements, or alcohol?
- What should I do if I miss a dose or take too much?