Drug · FAERS side-effect profile with label screen
Rifampin side effects: what 14,503 FDA adverse event reports show
Drug class
Rifamycin Antibacterial
FDA label (Established Pharmacologic Class)
Who reports
14,503 reports · 83% serious · 1,483 with death outcome · 50% female
openFDA FAERS counts, all years, deduplication not applied
Used for
In the treatment of both tuberculosis and the meningococcal carrier state, the small number of resistant cells present within large populations of susceptible cells can rapidly become the predominant type. Bacteriologic cultures should be obtained before the start of therapy to confirm the susceptibility of the organism to rifampin and they should be repeated throughout therapy to monitor the response to treatment.
FDA label, Indications and Usage
What it is
DESCRIPTION Rifampin is a semisynthetic antibiotic derivative of rifamycin SV. Rifampin is a red-brown crystalline powder very slightly soluble in water at neutral pH, freely soluble in chloroform, soluble in ethyl acetate and in methanol.
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 1Labeled (related wording) 8Likely indication confounding 5Lab value / disease marker 4Not in label — unassessed 22
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.
- 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. 1,047 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 |
|---|---|---|---|---|---|---|
| Type 2 lepra reaction | 61 | 695.3 512.2–943.9ROR 698.2 · χ² 27,957 / p <1e-300 | 407.6 EB05 328.8 · IC025 +6.2 3/3 methods agree | Not in label — unassessed | serious n=60 · ♀ 17% (drug 50%) · 100% clinician | no trial data cached |
| Immune reconstitution inflammatory syndrome associated tuberculosis | 99 | 613.3 484.8–775.8ROR 617.5 · χ² 41,880 / p <1e-300 | 396.1 EB05 334.8 · IC025 +6.8 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=99 · 100% clinician | no trial data cached |
| Mycobacterium ulcerans infection | 16 | 556.0 312.1–990.6ROR 556.6 · χ² 5,983 / p <1e-300 | 270.8 EB05 176.8 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=16 | no trial data cached |
| Type 1 lepra reaction | 10 | 347.5 174.1–693.6ROR 347.8 · χ² 2,506 / p <1e-300 | 182.7 EB05 106.1 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=8 | no trial data cached |
| Atypical mycobacterium test positive | 18 | 328.8 197.0–548.8ROR 329.2 · χ² 4,517 / p <1e-300 | 208.5 EB05 139.5 · IC025 +4.2 3/3 methods agree | Lab value / disease marker | serious n=7 | no trial data cached |
| Tuberculoma of central nervous system | 32 | 306.0 208.9–448.1ROR 306.7 · χ² 7,759 / p <1e-300 | 219.2 EB05 162.6 · IC025 +5.1 3/3 methods agree | Labeled (related wording) related wording | serious n=32 · ♀ 70% (drug 50%) · 100% clinician | no trial data cached |
| Atypical mycobacterial lower respiratory tract infection | 12 | 285.0 153.4–529.5ROR 285.2 · χ² 2,598 / p <1e-300 | 172.8 EB05 105.4 · IC025 +3.5 3/3 methods agree | Labeled (related wording) related wording | serious n=12 | no trial data cached |
| Multiple drug hypersensitivity | 10 | 233.6 119.7–455.8ROR 233.7 · χ² 1,795 / p <1e-300 | 145.7 EB05 84.6 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Anticoagulation drug level decreased | 17 | 232.9 139.5–388.8ROR 233.2 · χ² 3,177 / p <1e-300 | 163.8 EB05 108.3 · IC025 +4.1 3/3 methods agree | Lab value / disease marker | serious n=17 | no trial data cached |
| Pigment nephropathy | 11 | 220.7 117.0–416.5ROR 220.9 · χ² 1,897 / p <1e-300 | 144.1 EB05 85.8 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Mycobacterium avium complex infection | 291 | 177.5 157.3–200.3ROR 181.1 · χ² 45,261 / p <1e-300 | 156.3 EB05 141.8 · IC025 +6.8 3/3 methods agree | Not in label — unassessed | serious n=285 | no trial data cached |
| Tuberculosis of central nervous system | 29 | 176.6 120.1–259.6ROR 176.9 · χ² 4,350 / p <1e-300 | 142.6 EB05 104.2 · IC025 +4.8 3/3 methods agree | Labeled (related wording) related wording | serious n=29 · ♀ 0% (drug 50%) · 93% clinician | no trial data cached |
| Paradoxical drug reaction | 386 | 169.8 153.0–188.5ROR 174.5 · χ² 57,750 / p <1e-300 | 150.7 EB05 138.5 · IC025 +6.8 3/3 methods agree | Labeled adverse reaction exact term | serious n=379 · 99% clinician | no trial data cached |
| Bile acids increased | 16 | 159.4 95.1–267.2ROR 159.6 · χ² 2,125 / p <1e-300 | 122.8 EB05 80.2 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=7 | no trial data cached |
| Oligoarthritis | 19 | 155.6 96.9–249.8ROR 155.8 · χ² 2,493 / p <1e-300 | 123.3 EB05 83.4 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=19 | no trial data cached |
| Mycobacterium haemophilum infection | 24 | 150.6 98.9–229.4ROR 150.9 · χ² 3,092 / p <1e-300 | 123.2 EB05 87.1 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=24 · ♀ 22% (drug 50%) | no trial data cached |
| Disseminated mycobacterium avium complex infection | 20 | 150.0 94.6–237.7ROR 150.2 · χ² 2,545 / p <1e-300 | 120.5 EB05 82.3 · IC025 +4.2 3/3 methods agree | Labeled (related wording) related wording | serious n=20 · ♀ 70% (drug 50%) · 100% clinician | no trial data cached |
| Interferon gamma release assay positive | 14 | 133.9 77.4–231.5ROR 134.0 · χ² 1,568 / p <1e-300 | 105.3 EB05 66.7 · IC025 +3.7 3/3 methods agree | Lab value / disease marker | serious n=14 | no trial data cached |
| Hypoprothrombinaemia | 23 | 118.7 77.6–181.6ROR 118.9 · χ² 2,371 / p <1e-300 | 100.7 EB05 70.7 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=23 · 100% clinician | no trial data cached |
| Acid fast bacilli infection | 11 | 108.1 58.6–199.5ROR 108.2 · χ² 987 / p 5e-217 | 86.0 EB05 51.2 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Choroiditis | 23 | 94.2 61.8–143.6ROR 94.3 · χ² 1,902 / p <1e-300 | 82.5 EB05 57.9 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=23 · 100% clinician | no trial data cached |
| Alopecia scarring | 10 | 91.3 48.2–173.1ROR 91.4 · χ² 757 / p 7e-167 | 74.2 EB05 43.1 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=9 | no trial data cached |
| Mycobacterial infection | 102 | 90.9 74.5–111.0ROR 91.6 · χ² 8,445 / p <1e-300 | 84.2 EB05 71.4 · IC025 +5.6 3/3 methods agree | Labeled (related wording) related wording | serious n=102 · 98% clinician | no trial data cached |
| Mycobacterium test positive | 12 | 89.5 50.0–160.4ROR 89.6 · χ² 907 / p 2e-199 | 74.7 EB05 45.5 · IC025 +3.3 3/3 methods agree | Lab value / disease marker | – | no trial data cached |
| Disseminated bacillus calmette-guerin infection | 26 | 85.0 57.2–126.2ROR 85.1 · χ² 1,958 / p <1e-300 | 75.9 EB05 54.5 · IC025 +4.4 3/3 methods agree | Labeled (related wording) related wording | serious n=26 · ♀ 0% (drug 50%) · 100% clinician | no trial data cached |
| Cardiac valve vegetation | 25 | 79.2 52.9–118.4ROR 79.3 · χ² 1,754 / p <1e-300 | 71.1 EB05 50.7 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=25 · ♀ 0% (drug 50%) · 100% clinician | no trial data cached |
| Meningitis tuberculous | 29 | 78.4 54.0–113.9ROR 78.6 · χ² 2,028 / p <1e-300 | 71.0 EB05 51.9 · IC025 +4.4 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=29 · 100% clinician | no trial data cached |
| Vogt-koyanagi-harada disease | 11 | 78.0 42.5–143.0ROR 78.0 · χ² 721 / p 4e-159 | 65.9 EB05 39.3 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Pancreatitis haemorrhagic | 22 | 71.4 46.5–109.5ROR 71.5 · χ² 1,388 / p <1e-300 | 64.4 EB05 44.8 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=22 · ♀ 100% (drug 50%) · 100% clinician | no trial data cached |
| Disseminated tuberculosis | 112 | 66.5 55.0–80.3ROR 67.0 · χ² 6,838 / p <1e-300 | 62.9 EB05 53.7 · IC025 +5.3 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=112 · 95% clinician | no trial data cached |
| Immune reconstitution inflammatory syndrome | 210 | 63.2 55.1–72.5ROR 64.2 · χ² 12,261 / p <1e-300 | 60.3 EB05 53.7 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=210 · 98% clinician | no trial data cached |
| Antimicrobial susceptibility test resistant | 13 | 62.8 36.0–109.4ROR 62.8 · χ² 699 / p 2e-154 | 55.5 EB05 34.5 · IC025 +3.3 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=13 | no trial data cached |
| Oedematous kidney | 11 | 62.4 34.1–114.2ROR 62.5 · χ² 580 / p 2e-128 | 54.5 EB05 32.5 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Mycobacterium abscessus infection | 29 | 61.9 42.7–89.8ROR 62.1 · χ² 1,609 / p <1e-300 | 57.3 EB05 41.8 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=29 · 93% clinician | no trial data cached |
| Atypical mycobacterial infection | 55 | 59.4 45.4–77.7ROR 59.6 · χ² 2,974 / p <1e-300 | 56.0 EB05 44.6 · IC025 +4.8 3/3 methods agree | Labeled (related wording) related wording | serious n=55 | no trial data cached |
| Tuberculosis gastrointestinal | 12 | 56.8 31.9–101.1ROR 56.8 · χ² 580 / p 2e-128 | 50.5 EB05 30.8 · IC025 +3.1 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=12 | no trial data cached |
| Toxic optic neuropathy | 16 | 55.7 33.8–91.8ROR 55.8 · χ² 776 / p 5e-171 | 50.6 EB05 33.0 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=16 | no trial data cached |
| Pulmonary cavitation | 32 | 55.5 39.0–79.0ROR 55.7 · χ² 1,597 / p <1e-300 | 51.9 EB05 38.5 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=31 | no trial data cached |
| Urinary tract inflammation | 13 | 54.5 31.3–94.8ROR 54.5 · χ² 607 / p 3e-134 | 49.0 EB05 30.5 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Vascular purpura | 49 | 52.7 39.7–70.1ROR 52.9 · χ² 2,348 / p <1e-300 | 50.0 EB05 39.3 · IC025 +4.6 3/3 methods agree | Labeled (related wording) related wording | serious n=49 · ♀ 26% (drug 50%) · 100% clinician | 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 |
|---|---|---|---|---|---|---|
| Drug ineffective (drug did not work) | 1,608 | 1.8 1.7–1.8ROR 1.9 · χ² 568 / p 8e-126 | 1.8 EB05 1.7 · IC025 +0.7 | Reporting / coding artifact | serious PRR 3.0 · 91% clinician | no trial data cached |
| Off label use (used outside approved label) | 1,216 | 2.0 1.9–2.1ROR 2.1 · χ² 657 / p 3e-145 | 2.0 EB05 1.9 · IC025 +0.9 | Reporting / coding artifact | serious PRR 2.2 | no trial data cached |
| Drug interaction | 1,085 | 9.9 9.4–10.5ROR 10.7 · χ² 8,723 / p <1e-300 | 9.9 EB05 9.4 · IC025 +3.2 3/3 methods agree | Reporting / coding artifact | serious PRR 6.7 · 93% clinician | no trial data cached |
| Drug reaction with eosinophilia and systemic symptoms | 746 | 43.4 40.5–46.6ROR 45.7 · χ² 30,008 / p <1e-300 | 42.1 EB05 39.7 · IC025 +5.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 29.1 · 98% clinician | no trial data cached |
| Nausea | 680 | 1.2 1.2–1.3ROR 1.3 · χ² 34 / p 3e-9 | 1.2 EB05 1.2 · IC025 +0.2 | Labeled adverse reaction exact term | serious PRR 1.3 | no trial data cached |
| Condition aggravated | 619 | 3.0 2.7–3.2ROR 3.1 · χ² 815 / p 2e-179 | 3.0 EB05 2.8 · IC025 +1.4 3/3 methods agree | Reporting / coding artifact | serious PRR 2.9 · 93% clinician | no trial data cached |
| Product use in unapproved indication | 594 | 3.5 3.3–3.8ROR 3.6 · χ² 1,079 / p 7e-237 | 3.5 EB05 3.3 · IC025 +1.7 3/3 methods agree | Reporting / coding artifact | serious PRR 2.6 | no trial data cached |
| Pyrexia (fever) | 571 | 2.4 2.2–2.6ROR 2.4 · χ² 465 / p 2e-103 | 2.4 EB05 2.2 · IC025 +1.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 1.9 | no trial data cached |
| Vomiting | 485 | 1.5 1.4–1.6ROR 1.5 · χ² 81 / p 1e-19 | 1.5 EB05 1.4 · IC025 +0.4 | Labeled adverse reaction exact term | serious PRR 1.3 | no trial data cached |
| Drug resistance | 461 | 26.4 24.1–28.9ROR 27.2 · χ² 11,046 / p <1e-300 | 25.9 EB05 24.0 · IC025 +4.5 3/3 methods agree | Reporting / coding artifact | serious PRR 16.6 · 95% clinician | no trial data cached |
| Drug intolerance | 427 | 6.4 5.9–7.1ROR 6.6 · χ² 1,955 / p <1e-300 | 6.4 EB05 5.9 · IC025 +2.5 3/3 methods agree | Reporting / coding artifact | serious PRR 3.5 | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 423 | 4.0 3.7–4.4ROR 4.1 · χ² 961 / p 2e-211 | 4.0 EB05 3.7 · IC025 +1.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.8 · 95% clinician | no trial data cached |
| Dyspnoea (shortness of breath) | 414 | 1.1 1.0–1.2ROR 1.1 · χ² 1 / p 0.129 | 1.1 EB05 1.0 · IC025 -0.1 PRR-only: not supported by EBGM or IC | Labeled (related wording) related wording | serious PRR 0.8 | no trial data cached |
| Rash | 405 | 1.3 1.2–1.5ROR 1.4 · χ² 37 / p 6e-10 | 1.3 EB05 1.2 · IC025 +0.3 | Labeled adverse reaction exact term | serious PRR 1.7 | no trial data cached |
| Diarrhoea (diarrhea) | 404 | 0.9 0.8–1.0ROR 0.9 · χ² 4 / p 0.025 | 0.9 EB05 0.8 · IC025 -0.3 PRR-only: not supported by EBGM or IC | Labeled adverse reaction exact term | serious PRR 0.9 | 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.
- Type 2 lepra reaction — n=61, PRR 695.3
- Mycobacterium avium complex infection — n=291, PRR 177.5
- Mycobacterium haemophilum infection — n=24, PRR 150.6
- Hypoprothrombinaemia — n=23, PRR 118.7
- Choroiditis — n=23, PRR 94.2
- Cardiac valve vegetation — n=25, PRR 79.2
- Pancreatitis haemorrhagic — n=22, PRR 71.4
- Immune reconstitution inflammatory syndrome — n=210, PRR 63.2
- Mycobacterium abscessus infection — n=29, PRR 61.9
- Pulmonary cavitation — n=32, PRR 55.5
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 Rifampin?
In FDA FAERS, the most frequently co-reported reaction terms for Rifampin are drug reaction with eosinophilia and systemic symptoms, nausea, pyrexia, vomiting, acute kidney injury, dyspnoea. 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 Rifampin have an FDA boxed warning?
No. The FDA label retrieved for Rifampin has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Rifampin 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 28109dee-3e5e-492b-b7d9-9ba46c0b5324, effective 20250325; matched on
openfda.generic_name.exact:"RIFAMPIN") - 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, 1,087 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.