Prescription medication · Nitrofuran Antibiotic
nitrofurantoin
Also sold as Macrobid, Macrodantin. This medicine treats urinary tract infections (UTIs).
- 15,757
- FDA reportsModerately reported
- 4
- InteractionsFew interactions
- 1
- Recall record
What the data shows
nitrofurantoin (Macrobid) is a prescription Nitrofuran Antibiotic, reported less often than most tracked drugs (15,757 FDA reports), with 4 documented drug interactions.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
nitrofurantoin (Macrobid) is a prescription Nitrofuran Antibiotic. This medicine treats urinary tract infections (UTIs).
Nitrofurantoin is an antibiotic medicine. It is used to treat infections of the urinary tract.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Generic Price
$3.87/unit
Generic Available
Yes (21 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
This medicine treats urinary tract infections (UTIs).
Common side effects
Nausea, Headache, Vomiting
Key warnings
This medicine can cause serious side effects.
The sections below are summarized in plain English from nitrofurantoin's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Nitrofurantoin is an antibiotic that stops bacteria from growing. It damages the bacteria's DNA, which kills the bacteria. This helps to clear up the infection in your urinary tract.
How to Take It
Take this medicine exactly as your doctor tells you. Adults usually take 50 mg to 100 mg four times a day. Children's doses are based on their weight. Always take nitrofurantoin with food to help your body absorb it better.
This is a plain-language summary of nitrofurantoin's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
Do not take this medicine if you are 38-42 weeks pregnant or in labor. It could cause anemia in the baby. Talk to your doctor if you are pregnant or breastfeeding.
This is a plain-language summary of nitrofurantoin's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule.
This is a plain-language summary of nitrofurantoin's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store this medicine at room temperature, away from strong light and freezing temperatures. Keep out of reach of children.
Side Effects (from patient reports)
Based on 15,757 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for nitrofurantoin, by number of reports
- Urinary tract infection
Urinary tract infection
1,301 reports
- Tiredness
Tiredness
1,240 reports
- Feeling sick to your stomach
Feeling sick to your stomach
1,186 reports
- Head pain
Head pain
1,103 reports
- Pain
Pain
964 reports
- Difficulty breathing
Difficulty breathing
950 reports
- Loose stools
Loose stools
879 reports
- Skin irritation
Skin irritation
852 reports
- General feeling of discomfort
General feeling of discomfort
851 reports
- Throwing up
Throwing up
810 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for nitrofurantoin each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where nitrofurantoin sits
nitrofurantoin has more FDA adverse-event reports than 49% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is nitrofurantoin; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 15,757 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
15,757
Reports Mentioning Death
1,000
6.3% of reports — not proof of cause
Hospitalization Reports
5,435
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | URINARY TRACT INFECTION | 1,301 |
| 2 | FATIGUE | 1,240 |
| 3 | NAUSEA | 1,187 |
| 4 | HEADACHE | 1,103 |
| 5 | PAIN | 964 |
| 6 | DYSPNOEA | 950 |
| 7 | DIARRHOEA | 880 |
| 8 | RASH | 852 |
| 9 | MALAISE | 851 |
| 10 | VOMITING | 810 |
| 11 | PYREXIA | 796 |
| 12 | DIZZINESS | 788 |
| 15 | CHRONIC KIDNEY DISEASE | 588 |
| 16 | FALL | 585 |
| 17 | WEIGHT DECREASED | 577 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
This medicine can cause serious side effects. Rarely, it can cause deadly allergic reactions, lung problems, liver problems, and nerve damage. Tell your doctor right away if you have trouble breathing, yellowing of the skin, numbness, or tingling.
Known Drug Interactions
7.4 Concomitant Use with Drugs that Induce Methemoglobinemia Concomitant use of ACZONE Gel, 7.5% with drugs that induce methemoglobinemia such as sulfonamides, acetaminophen, acetanilide, aniline dyes, benzocaine, chloroquine, dapsone, naphthalene, nitrates and nitrites, nitrofurantoin, nitroglycerin, nitroprusside, pamaquine, para‐aminosalicylic acid, phenacetin, phenobarbital, phenytoin, primaquine, and quinine may increase the risk for developing methemoglobinemia [see Warnings and Precautions ( 5.1 )] .
Mechanism: These medications both have the potential to change how your blood carries oxygen. Using them at the same time makes it more likely you will develop a blood problem called methemoglobinemia.
What to do: Your doctor should monitor you closely for symptoms like headache, tiredness, or blue-tinted skin while using these drugs together.
Drugs That May Cause Methemoglobinemia When Used with LIDODERM Patients who are administered local anesthetics are at increased risk of developing methemoglobinemia when concurrently exposed to the following drugs, which could include other local anesthetics: Examples of Drugs Associated with Methemoglobinemia : Class Examples Nitrates/Nitrites nitric oxide, nitroglycerin, nitroprusside, nitrous oxide Local anesthetics articaine, benzocaine, bupivacaine, lidocaine, mepivacaine, prilocaine, procaine, ropivacaine, tetracaine Antineoplastic agents cyclophosphamide, flutamide, hydroxyurea,...
Mechanism: Both drugs can cause a blood problem that makes it hard for your body to get enough oxygen. Using them together increases the risk of this serious condition.
What to do: Your doctor should monitor you closely for signs of low oxygen, like blue skin or trouble breathing. Use this combination with caution.
7.2 Uricosuric Drugs Uricosuric drugs, such as probenecid and sulfinpyrazone, can inhibit renal tubular secretion of nitrofurantoin.
Mechanism: Probenecid stops the kidneys from moving nitrofurantoin into the urine, which can make the antibiotic less effective for treating a bladder infection.
What to do: Your doctor may need to monitor your treatment closely or choose a different medication to ensure your infection is treated properly.
Examples of Drugs Associated with Methemoglobinemia: Class Examples Nitrates/Nitrites nitric oxide, nitroglycerin, nitroprusside, nitrous oxide Local anesthetics articaine, benzocaine, bupivacaine, lidocaine, mepivacaine, prilocaine, procaine, ropivacaine, tetracaine Antineoplastic agents cyclophosphamide, flutamide, hydroxyurea, isofamide, rasburicase Antibiotics dapsone, nitrofurantoin, para-aminosalicylic acid, sulfonamides Antimalarials chloroquine, primaquine Anticonvulsants phenobarbital, phenytoin, sodium valproate Other drugs acetaminophen, metoclopramide, quinine, sulfasalazine...
Mechanism: These medications can both contribute to a blood disorder that prevents oxygen from reaching your body's tissues properly. This is a rare but serious side effect mentioned in the drug safety information.
What to do: Watch for signs of low oxygen, such as feeling very tired or having a headache, and report them to your healthcare provider.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
Common Questions
Can I take this medicine if I am allergic to other antibiotics?
Can I drive while taking this medicine?
How long should I take this medicine?
What should I do if I get diarrhea while taking this medicine?
Can this medicine affect my liver?
Can this medicine affect my nerves?
Can I take antacids with this medicine?
What if my symptoms don't improve?
Can this medicine change my urine color?
Is it okay to drink alcohol while taking this medication?
What are the common side effects of nitrofurantoin?
Does nitrofurantoin interact with other medications?
What drug class is nitrofurantoin?
Is nitrofurantoin safe during pregnancy?
Has nitrofurantoin been recalled?
Active Recalls
Failed Dissolution Specifications
AvKARE
Related Medications in Nitrofuran Antibiotic
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amoxicillin/clavulanate
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azithromycin
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What the FDA Data Shows for nitrofurantoin
The FDA label for nitrofurantoin (sold under brand names such as Macrobid, Macrodantin) classifies it as a prescription-only medication in the Nitrofuran Antibiotic class. This medicine treats urinary tract infections (UTIs). Official labeling lists 3 commonly reported side effects, including Nausea, Headache, Vomiting.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 15,757 voluntary reports. The database also lists 4 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. NADAC pricing from CMS shows a generic unit cost of $3.87.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 1 recall record on file), and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: March 29, 2024
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages