Pharmacologic class (EPC) · 2 drug pages

Nitrofuran antibacterial: adverse event reports filed with FDA

6,868 reports list a drug in this class as a suspect or interacting product, 2004–2026.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event." The information in these reports "cannot be used to estimate the incidence of these events."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

6,868
reports across the class: 0% of all reports; 499
reports, 12 months to June 2026: 427 in the 12 months before; 78.8%
marked serious by the reporter: 57.4% across all reports; 2
drugs with a page: brand and generic names counted separately

Nitrofuran antibacterial is a pharmacologic class (an FDA Established Pharmacologic Class) with 2 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 6,868 adverse event reports received by FDA, 0% of the database, from January 2004 to June 2026.

499 reports arrived in the 12 months to June 2026, up 17% from 427 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 78.8% of the class's reports are marked serious, 5.1% record death among the outcomes and 32.5% record hospitalisation, as reported.

Across the class the reactions recorded most often are drug hypersensitivity (12.5%), nausea (9.9%) and dyspnoea (9.6%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is 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."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
Nitrofurantoin (monohydrate/macrocrystals)	generic	5,292	446	84.2%	Dyspnoea
MacrobidNitrofurantoin monohydrate/macrocrystalline	brand	1,576	53	60.9%	Drug hypersensitivity

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."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Drug hypersensitivityan allergic-type reaction to a medicine12.5%857
Nauseafeeling sick9.9%678
Dyspnoeashortness of breath9.6%659
Vomitingbeing sick8.1%556
Headachehead pain7.6%525
Pyrexiafever7.3%503
Fatiguetiredness7.3%502
Malaisegeneral feeling of being unwell7.3%501
Rashskin rash7.3%501
Urinary tract infectionbladder or urinary infection6.7%463
Dizzinesslight-headedness or unsteadiness6.5%448
Diarrhoealoose or frequent stools5.7%394
Pruritusitching5.2%356
Drug ineffectivethe medicine did not work as expected4.9%335
Coughcough4.4%300
Painpain, site not specified4.2%290
Chillschills or shivering4.2%287
Urticariahives4.1%285
Abdominal painstomach or belly pain4.1%281
Arthralgiajoint pain3.9%271
Abdominal pain upperupper stomach pain3.9%265
Drug-induced liver injury3.6%245
Astheniaweakness or lack of energy3.5%243
Feeling abnormalfeeling odd or not right3.5%241
Cystitis3.4%234

Solid bar: share of all class reports. Hollow bar: the median share across the 2 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death5.1%353

Life-threatening6.8%465

Hospitalisation (initial or prolonged)32.5%2,230

Disability5.6%388

Congenital anomaly1.4%93

Other serious55.9%3,841

Not serious21.2%1,453

Patient age

Under 20.5%33

2 to 110.3%19

12 to 170.6%41

18 to 4413.2%907

45 to 6424.3%1,668

65 to 7415.8%1,086

75 and over20.9%1,438

Age not given24.4%1,676

Who reported

Physician25.8%1,775

Pharmacist9%619

Other health professional28.4%1,953

Lawyer0.3%22

Consumer or non-health professional31.1%2,133

Not given5.3%366

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about Nitrofuran antibacterial reports

Which drugs are in the Nitrofuran antibacterial class on this site?

Nitrofurantoin (monohydrate/macrocrystals) and Macrobid. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

6,868 reports through June 2026, 499 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

drug hypersensitivity (12.5%), nausea (9.9%), dyspnoea (9.6%), vomiting (8.1%) and headache (7.6%).

Can the members table be used to rank the drugs?

No. 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." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. 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 class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. 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.