Drug · FAERS side-effect profile with label screen
Nitrofurantoin and Macrocrystalline side effects: what 5,819 FDA adverse event reports show
Drug class
Nitrofuran antibacterial
FDA label, Indications wording of the closest related product
Label matched
Nitrofurantoin (Nitrofurantoin)
closest FDA label found for this product string; brand list suppressed because the label is a related product, not an exact match
Who reports
5,819 reports · 68% serious · 333 with death outcome · 89% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Nitrofurantoin oral suspension is indicated in adults and pediatric patients 1 month of age and older for the treatment of urinary tract infections due to susceptible strains of Escherichia coli, Enterococcus species , Staphylococcus aureus, Klebsiella species and Enterobacter species.
FDA label, Indications and Usage
What it is
Nitrofurantoin oral suspension, USP contains nitrofurantoin, a synthetic nitrofuran antibacterial agent specific for urinary tract infections.
FDA label, Description section
Boxed warning
None in the current label
How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation.
Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)?
That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.
Causality screen of the 40 strongest signals
Labeled adverse reaction 3Labeled (related wording) 2Likely indication confounding 2Reporting / coding artifact 4Lab value / disease marker 3Not in label — unassessed 26
What the badges mean
- Labeled adverse reaction The exact term appears in the label's warnings or adverse-reactions sections: a known, expected effect. The FAERS signal confirms the label rather than discovering anything.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only and flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 642 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Cystitis | 222 | 25.2 22.1–28.7ROR 26.2 · χ² 5,107 / p <1e-300 | 25.0 EB05 22.3 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious PRR 25.1 | no trial data cached |
| Swollen tongue | 198 | 23.0 20.0–26.3ROR 23.7 · χ² 4,118 / p <1e-300 | 22.8 EB05 20.2 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious PRR 26.8 | no trial data cached |
| Urinary tract infection (bladder infection) | 807 | 17.2 16.1–18.3ROR 19.8 · χ² 12,322 / p <1e-300 | 17.1 EB05 16.1 · IC025 +4.0 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 14.9 | no trial data cached |
| Angioedema (deep swelling of face/throat) | 200 | 16.4 14.3–18.8ROR 16.9 · χ² 2,870 / p <1e-300 | 16.3 EB05 14.5 · IC025 +3.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 14.5 | no trial data cached |
| Kidney infection | 78 | 14.4 11.5–17.9ROR 14.6 · χ² 955 / p 5e-210 | 14.2 EB05 11.7 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 12.6 | no trial data cached |
| Dysphonia | 215 | 13.3 11.7–15.2ROR 13.8 · χ² 2,433 / p <1e-300 | 13.2 EB05 11.8 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 20.7 | no trial data cached |
| Swelling face | 205 | 11.4 10.0–13.0ROR 11.8 · χ² 1,933 / p <1e-300 | 11.3 EB05 10.0 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 15.1 | no trial data cached |
| Hyperlipidaemia | 35 | 10.6 7.6–14.7ROR 10.6 · χ² 292 / p 7e-66 | 10.0 EB05 7.3 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 9.5 | no trial data cached |
| Drug hypersensitivity | 550 | 10.2 9.4–11.1ROR 11.2 · χ² 4,602 / p <1e-300 | 10.2 EB05 9.5 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 7.1 | no trial data cached |
| Flank pain | 26 | 10.0 6.8–14.7ROR 10.1 · χ² 202 / p 4e-46 | 9.2 EB05 6.4 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 10.2 · 74% consumer | no trial data cached |
| Micturition urgency | 31 | 9.9 7.0–14.0ROR 9.9 · χ² 238 / p 5e-54 | 9.2 EB05 6.6 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 11.9 · ♀ 63% (drug 89%) | no trial data cached |
| Urosepsis | 25 | 9.8 6.6–14.5ROR 9.8 · χ² 188 / p 4e-43 | 8.9 EB05 6.2 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious PRR 8.2 · ♀ 64% (drug 89%) | no trial data cached |
| Drug ineffective for unapproved indication | 144 | 9.3 7.9–11.0ROR 9.5 · χ² 1,063 / p 2e-233 | 9.2 EB05 8.0 · IC025 +2.9 3/3 methods agree | Reporting / coding artifact | serious PRR 17.2 | no trial data cached |
| Atelectasis | 24 | 8.9 6.0–13.3ROR 9.0 · χ² 161 / p 3e-37 | 8.0 EB05 5.5 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 7.0 | no trial data cached |
| Mitral valve incompetence | 28 | 8.9 6.2–12.9ROR 9.0 · χ² 189 / p 3e-43 | 8.2 EB05 5.8 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 7.6 · ♀ 68% (drug 89%) | no trial data cached |
| Bladder disorder | 24 | 8.7 5.8–13.0ROR 8.7 · χ² 156 / p 4e-36 | 7.8 EB05 5.4 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious n=22 | no trial data cached |
| Sleep apnoea syndrome | 45 | 8.5 6.3–11.4ROR 8.6 · χ² 290 / p 3e-65 | 8.0 EB05 6.2 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 8.3 | no trial data cached |
| Drug intolerance | 226 | 8.5 7.5–9.6ROR 8.8 · χ² 1,487 / p <1e-300 | 8.4 EB05 7.5 · IC025 +2.8 3/3 methods agree | Reporting / coding artifact | serious PRR 10.9 | no trial data cached |
| Economic problem | 35 | 8.2 5.9–11.4ROR 8.2 · χ² 214 / p 1e-48 | 7.6 EB05 5.6 · IC025 +2.3 3/3 methods agree | Reporting / coding artifact | serious PRR 7.5 | no trial data cached |
| Glomerular filtration rate decreased | 27 | 8.0 5.5–11.7ROR 8.1 · χ² 159 / p 8e-37 | 7.3 EB05 5.2 · IC025 +2.2 3/3 methods agree | Lab value / disease marker | serious PRR 6.8 | no trial data cached |
| Drug exposure during pregnancy | 76 | 8.0 6.4–9.9ROR 8.0 · χ² 455 / p 3e-101 | 7.7 EB05 6.3 · IC025 +2.5 3/3 methods agree | Reporting / coding artifact | serious PRR 7.1 · ♀ 59% (drug 89%) | no trial data cached |
| Cholecystectomy | 25 | 7.9 5.4–11.8ROR 8.0 · χ² 145 / p 1e-33 | 7.1 EB05 5.0 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 6.9 · 78% consumer | no trial data cached |
| Injury | 151 | 7.7 6.6–9.0ROR 7.9 · χ² 877 / p 5e-193 | 7.6 EB05 6.6 · IC025 +2.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.9 | no trial data cached |
| Dysuria (painful urination) | 78 | 7.6 6.1–9.5ROR 7.7 · χ² 444 / p 9e-99 | 7.4 EB05 6.1 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 7.8 | no trial data cached |
| Cardiomegaly | 26 | 7.6 5.2–11.1ROR 7.6 · χ² 141 / p 6e-33 | 6.8 EB05 4.8 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 | no trial data cached |
| Urinary retention | 67 | 7.3 5.7–9.2ROR 7.3 · χ² 356 / p 1e-79 | 7.0 EB05 5.7 · IC025 +2.4 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 6.6 · ♀ 62% (drug 89%) | no trial data cached |
| Presyncope (near-fainting) | 48 | 7.2 5.4–9.5ROR 7.2 · χ² 248 / p 3e-56 | 6.8 EB05 5.3 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 7.4 | no trial data cached |
| Incontinence | 21 | 7.2 4.7–11.0ROR 7.2 · χ² 105 / p 6e-25 | 6.3 EB05 4.3 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 7.7 | no trial data cached |
| Bipolar disorder | 21 | 6.9 4.5–10.6ROR 6.9 · χ² 100 / p 6e-24 | 6.1 EB05 4.2 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.7 | no trial data cached |
| Sputum discoloured | 18 | 6.9 4.3–10.9ROR 6.9 · χ² 84 / p 2e-20 | 6.0 EB05 4.0 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 7.6 | no trial data cached |
| Blood urine present | 36 | 6.8 4.9–9.4ROR 6.9 · χ² 173 / p 9e-40 | 6.3 EB05 4.8 · IC025 +2.1 3/3 methods agree | Lab value / disease marker | serious PRR 6.6 | no trial data cached |
| Upper respiratory tract infection (cold/sinus infection) | 86 | 6.7 5.5–8.3ROR 6.8 · χ² 414 / p 3e-92 | 6.5 EB05 5.4 · IC025 +2.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 8.5 | no trial data cached |
| Eosinophilia | 32 | 6.6 4.7–9.3ROR 6.6 · χ² 147 / p 5e-34 | 6.1 EB05 4.5 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.8 | no trial data cached |
| Ventricular extrasystoles | 19 | 6.6 4.2–10.3ROR 6.6 · χ² 85 / p 2e-20 | 5.8 EB05 3.9 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 | no trial data cached |
| Intervertebral disc degeneration | 17 | 6.6 4.1–10.6ROR 6.6 · χ² 75 / p 2e-18 | 5.7 EB05 3.7 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 | no trial data cached |
| Blood potassium decreased | 54 | 6.5 5.0–8.4ROR 6.5 · χ² 245 / p 2e-55 | 6.2 EB05 4.9 · IC025 +2.2 3/3 methods agree | Lab value / disease marker | serious PRR 6.2 | no trial data cached |
| Cholelithiasis | 57 | 6.3 4.8–8.1ROR 6.3 · χ² 247 / p 5e-56 | 6.0 EB05 4.8 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 5.5 | no trial data cached |
| Pulmonary congestion | 23 | 6.3 4.2–9.4ROR 6.3 · χ² 97 / p 4e-23 | 5.6 EB05 3.9 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.9 | no trial data cached |
| Renal tubular necrosis | 17 | 6.2 3.9–10.0ROR 6.3 · χ² 70 / p 4e-17 | 5.4 EB05 3.6 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 5.3 | no trial data cached |
| Fibromyalgia | 41 | 6.1 4.5–8.3ROR 6.1 · χ² 169 / p 5e-39 | 5.7 EB05 4.4 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 · 71% consumer | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Urinary tract infection (bladder infection) | 807 | 17.2 16.1–18.3ROR 19.8 · χ² 12,322 / p <1e-300 | 17.1 EB05 16.1 · IC025 +4.0 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 14.9 | no trial data cached |
| Headache | 608 | 3.5 3.2–3.8ROR 3.8 · χ² 1,117 / p 4e-245 | 3.5 EB05 3.3 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.1 | no trial data cached |
| Nausea | 585 | 2.7 2.5–2.9ROR 2.9 · χ² 635 / p 2e-140 | 2.7 EB05 2.5 · IC025 +1.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.4 | no trial data cached |
| Drug hypersensitivity | 550 | 10.2 9.4–11.1ROR 11.2 · χ² 4,602 / p <1e-300 | 10.2 EB05 9.5 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 7.1 | no trial data cached |
| Fatigue (tiredness) | 535 | 2.5 2.3–2.7ROR 2.6 · χ² 490 / p 6e-109 | 2.5 EB05 2.3 · IC025 +1.2 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.1 | no trial data cached |
| Pain | 503 | 2.9 2.7–3.2ROR 3.1 · χ² 665 / p 8e-147 | 2.9 EB05 2.7 · IC025 +1.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.4 | no trial data cached |
| Dyspnoea (shortness of breath) | 441 | 2.8 2.6–3.1ROR 3.0 · χ² 527 / p 7e-117 | 2.8 EB05 2.6 · IC025 +1.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.9 | no trial data cached |
| Diarrhoea (diarrhea) | 371 | 2.1 1.9–2.3ROR 2.2 · χ² 213 / p 1e-48 | 2.1 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | serious PRR 2.3 | no trial data cached |
| Dizziness | 366 | 2.7 2.4–2.9ROR 2.8 · χ² 383 / p 1e-85 | 2.6 EB05 2.4 · IC025 +1.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.1 | no trial data cached |
| Vomiting | 346 | 2.7 2.4–2.9ROR 2.8 · χ² 365 / p 1e-81 | 2.7 EB05 2.4 · IC025 +1.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.9 | no trial data cached |
| Asthenia (weakness) | 316 | 3.0 2.7–3.4ROR 3.1 · χ² 435 / p 6e-97 | 3.0 EB05 2.7 · IC025 +1.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.1 | no trial data cached |
| Pyrexia (fever) | 303 | 3.2 2.8–3.5ROR 3.3 · χ² 451 / p 2e-100 | 3.1 EB05 2.9 · IC025 +1.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.9 | no trial data cached |
| Fall | 299 | 3.2 2.9–3.6ROR 3.4 · χ² 469 / p 3e-104 | 3.2 EB05 2.9 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 2.9 | no trial data cached |
| Rash | 290 | 2.4 2.2–2.7ROR 2.5 · χ² 243 / p 4e-55 | 2.4 EB05 2.2 · IC025 +1.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.1 | no trial data cached |
| Arthralgia (joint pain) | 272 | 2.4 2.1–2.7ROR 2.4 · χ² 218 / p 2e-49 | 2.4 EB05 2.1 · IC025 +1.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.1 | no trial data cached |
Unlabeled candidate signals
These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.
- Cystitis — n=222, PRR 25.2
- Swollen tongue — n=198, PRR 23.0
- Kidney infection — n=78, PRR 14.4
- Dysphonia — n=215, PRR 13.3
- Swelling face — n=205, PRR 11.4
- Hyperlipidaemia — n=35, PRR 10.6
- Flank pain — n=26, PRR 10.0
- Micturition urgency — n=31, PRR 9.9
- Urosepsis — n=25, PRR 9.8
- Atelectasis — n=24, PRR 8.9
✓ A hand-written Bradford Hill causality assessment exists for this drug: Nitrofurantoin ↔ Pulmonary fibrosis / interstitial lung disease.
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Nitrofurantoin and Macrocrystalline?
In FDA FAERS, the most frequently co-reported reaction terms for Nitrofurantoin and Macrocrystalline are urinary tract infection, headache, nausea, drug hypersensitivity, fatigue, pain. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Nitrofurantoin and Macrocrystalline have an FDA boxed warning?
No. The FDA label retrieved for Nitrofurantoin and Macrocrystalline has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Nitrofurantoin and Macrocrystalline causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID 11e700aa-66f9-4939-8a6b-a23240ae1a0b, effective 20240516; matched on
openfda.generic_name.exact:"NITROFURANTOIN") - Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 682 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath
Page generated 2026-10-08. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.