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Nitrofurantoin (Macrocryst25%)

Pronounced

"NYE-trow-fyour-AN-toe-in"

Common brand names:

Macrobid

Uses

This medication is an antibiotic used to treat bladder infections (acute cystitis). It works by stopping the growth of bacteria.

This antibiotic treats only bacterial infections. It will not work for viral infections (such as common cold, flu). Using any antibiotic when it is not needed can cause it to not work for future infections.

This medication should not be used in infants younger than 1 month old (see also Precautions section). This drug should not be used to treat infections outside the bladder (including kidney infections such as pyelonephritis or perinephric abscesses).

How to Use This Medication

Take this medication by mouth with food as directed by your doctor, usually twice daily (every 12 hours). Swallow the medication whole for best results.

Do not use magnesium trisilicate-containing antacids while taking this medication. These antacids can bind with nitrofurantoin, preventing its full absorption into your system.

For the best effect, take this antibiotic at evenly spaced times. To help you remember, take this medication at the same time(s) every day.

Continue to take this medication until the full prescribed amount is finished, even if symptoms disappear after a few days. Stopping the medication too early may result in a return of the infection.

Tell your doctor if your condition lasts or gets worse.

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Drug information is selected from data included with permission and copyrighted by First DataBank, Inc. This is a summary and does not contain all possible information about this product. For complete information about this product or your specific health needs, ask your healthcare professional. Always seek the advice of your healthcare professional if you have any questions about this product or your medical condition. This information is not intended as individual medical advice and does not substitute for the knowledge and judgment of your healthcare professional. This information does not contain any assurances that this product is safe, effective or appropriate for you.

This information is intended only for residents of the United States. Products sold under the same brand names in other countries may contain different ingredients.

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Information expires December 2025.