Drugs › Nitrofuran antibacterial
Generic name
Nitrofurantoin (monohydrate/macrocrystals): adverse event reports filed with FDA
5,292 reports list it as a suspect or interacting product, 2004–2026. Class: Nitrofuran antibacterial. Also reported as Nitrofurantoin Capsules Usp 100mg, Nitrofurantoin Capsules Usp, Nitrofurantoin 100mg.
- 5,292
- reports as suspect product
- 0% of all reports · about 235 a year
- 446
- reports, 12 months to June 2026
- 381 in the 12 months before
- 84.2%
- marked serious by the reporter
- 78.8% across the class
- 5.7%
- record death among outcomes, as reported
- 303 reports · not verified by FDA
5,292 adverse event reports received by FDA list nitrofurantoin (monohydrate/macrocrystals), a generic name as a suspect or interacting product, from January 2004 to June 2026. A further 11,443 reports list it only as a concomitant medication, and those are not counted in the figures on this page.
In the 12 months to June 2026, 446 reports listed it, up 17% from 381 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 235 reports a year and 0% of the 20,646,523 reports in the database, and 77.1% of the reports for the nitrofuran antibacterial class. How many people take it is not in the data, so a count is not a rate of occurrence.
The reactions recorded most often are dyspnoea (8.8%), nausea (8.7%) and vomiting (7.5%). A report can list several reactions, so shares add to more than 100%; 1,016 different terms appear across these reports. Dyspnoea is recorded in 8.8% of these reports, about the same share as in the median nitrofuran antibacterial drug (10.5%).
84.2% of the reports are marked serious by the reporter (78.8% across the class); 5.7% record death among the outcomes and 34.4% record hospitalisation, as reported. 30.3% of the reports came from other health professionals, and the largest patient age group is 45 to 64 (24.9%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."
Reports by month, five years
Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.
By year received
2026 covers reports received through June 2026 only.
Reactions recorded in the reports
share of Nitrofurantoin (monohydrate/macrocrystals) reports recording the termmedian drug in nitrofuran antibacterial
- Dyspnoeashortness of breath8.8%468
- Nauseafeeling sick8.7%460
- Vomitingbeing sick7.5%397
- Malaisegeneral feeling of being unwell7.4%392
- Drug hypersensitivityan allergic-type reaction to a medicine7.1%377
- Headachehead pain6.9%367
- Rashskin rash6.7%354
- Fatiguetiredness6.7%353
- Pyrexiafever6.6%350
- Dizzinesslight-headedness or unsteadiness5.8%306
- Diarrhoealoose or frequent stools5.6%296
- Urinary tract infectionbladder or urinary infection5.2%273
- Pruritusitching4.7%250
- Drug-induced liver injury4.5%236
- Coughcough4.4%233
- Drug ineffectivethe medicine did not work as expected3.9%209
- Chillschills or shivering3.8%203
- Urticariahives3.8%200
- Abdominal painstomach or belly pain3.7%198
- Abdominal pain upperupper stomach pain3.6%188
- Painpain, site not specified3.3%173
- Chest painchest pain3.2%171
- Interstitial lung diseasescarring or inflammation of lung tissue3.2%171
- Arthralgiajoint pain3.2%170
- Feeling abnormalfeeling odd or not right3.1%166
- Pneumonialung infection3.1%164
- Astheniaweakness or lack of energy3%158
- Hyperhidrosisexcessive sweating2.8%147
- Cystitis2.7%144
- Weight decreasedweight loss2.7%143
Top 30 of 1,016 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the median share across the 2 drugs in the nitrofuran antibacterial class; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Outcomes recorded
Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 6,868 reports in the class. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."
Patients and reporters
Patient age
Patient sex
Who reported
Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 43.5% of reports give the United States as the country of the event or reporter.
Reason for use recorded
| Indication as recorded (MedDRA) | Reports | Share |
|---|---|---|
| Urinary tract infection | 2,154 | 40.7% |
| Cystitis | 323 | 6.1% |
| Prophylaxis urinary tract infection | 136 | 2.6% |
| Ill-defined disorder | 99 | 1.9% |
| Antibiotic therapy | 50 | 0.9% |
| Prophylaxis | 32 | 0.6% |
The indication field is filled in by the reporter and is often blank; shares are of all 5,292 reports.
Drugs most often listed in the same reports
| Drug (any role in the report) | Reports | Share of Nitrofurantoin (monohydrate/macrocrystals) reports |
|---|---|---|
| Ciprofloxacin | 339 | 6.4% |
| Atorvastatin | 312 | 5.9% |
| Omeprazole | 302 | 5.7% |
| Acetaminophen | 295 | 5.6% |
| Prednisone | 278 | 5.3% |
| Furosemide | 276 | 5.2% |
| Aspirin | 222 | 4.2% |
| Gabapentin | 211 | 4% |
| Levothyroxine | 209 | 3.9% |
| Albuterol | 190 | 3.6% |
Other products listed in reports where Nitrofurantoin (monohydrate/macrocrystals) is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.
In context
| Measure | Nitrofurantoin (monohydrate/macrocrystals) | Nitrofuran antibacterial | All reports |
|---|---|---|---|
| Reports as suspect product | 5,292 | 6,868 | 20,646,523 |
| Share of that pool | — | 77.1% | 0% |
| Reports, latest 12 months | 446 | — | 1,332,454 |
| Marked serious | 84.2% | 78.8% | 57.4% |
| Death recorded among outcomes, per 1,000 reports | 57 | 51 | 91 |
| Hospitalisation recorded, per 1,000 reports | 344 | 325 | 213 |
| Consumer-filed share | 27.9% | 31.1% | 45.8% |
| Top term, share of reports | Dyspnoea 8.8% | median 10.5% | 2.7% |
Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."
Other drugs in the nitrofuran antibacterial class
| Drug | Name type | Reports | Latest 12 months | Marked serious |
|---|---|---|---|---|
| Macrobid | brand | 1,576 | 53 | 60.9% |
Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." A brand and its generic are separate rows because reporters name them separately.
Questions about Nitrofurantoin (monohydrate/macrocrystals) reports
How many adverse event reports has FDA received for Nitrofurantoin (monohydrate/macrocrystals)?
5,292 reports list Nitrofurantoin (monohydrate/macrocrystals) as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 446 of them arrived in the latest 12 months. Another 11,443 list it only as a concomitant medication.
What reactions are recorded in Nitrofurantoin (monohydrate/macrocrystals) reports?
dyspnoea (8.8%), nausea (8.7%), vomiting (7.5%), malaise (7.4%) and drug hypersensitivity (7.1%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Nitrofurantoin (monohydrate/macrocrystals) was responsible.
How serious are the reports?
84.2% are marked serious by the reporter. Among the outcomes recorded, 5.7% of reports include death and 34.4% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.
Who files these reports?
other health professional (30.3%), consumer or non-health professional (27.9%) and physician (26.9%). Most reports reach FDA through the manufacturer, which must forward reports it receives.
Are reports for Nitrofurantoin (monohydrate/macrocrystals) rising?
446 reports in the 12 months to June 2026, up 17% from 381 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.
Do these reports show that Nitrofurantoin (monohydrate/macrocrystals) was responsible for these reactions?
No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.
Is this a list of the side effects of Nitrofurantoin (monohydrate/macrocrystals)?
No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.
How do I report an adverse event?
Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.
Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Nitrofurantoin (monohydrate/macrocrystals) as a suspect or interacting product; reports listing it only as a concomitant medication (11,443) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.
Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.