Linezolid side effects: what 29,593 FDA adverse event reports show
Drug class
Oxazolidinone Antibacterial
Who reports
29,593 reports · 91% serious · 5,443 with death outcome · 44% female
Used for
Linezolid is an oxazolidinone-class antibacterial indicated in adults and children for the treatment of the following infections caused by susceptible Gram-positive bacteria: Nosocomial pneumonia (1.1); Community-acquired pneumonia ( 1.2 ); Complicated.
What it is
Linezolid Tablets contain linezolid, which is a synthetic antibacterial agent of the oxazolidinone class.
Boxed warning
None in the current label
Causality screen of the 40 strongest signals
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, for the 300 most-reported drugs, adjusted for age band), and flags pairs whose reports are unusually skewed by sex or come mostly from consumers. Each row also shows the PRR against the other drugs of the same FDA class, which removes most confounding by the condition being treated, and a calibrated p-value: on validation, known non-causes average an ROR of about 2, so significance is judged against that empirical null (✓ = p < 0.05 after calibration). 1,131 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Anti factor v antibody | 14 | 1,221.8 512.6–2,912.2ROR 1,222.3 · calibrated p 8e-14 ✓ | 276.8 EB05 175.3 · IC025 +3.9 3/3 methods agree | Lab value / disease marker | serious n=14 | not reported in cached trials |
| Minimum inhibitory concentration | 18 | 837.8 422.3–1,662.2ROR 838.3 · calibrated p 1e-13 ✓ | 271.5 EB05 181.7 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=17 | not reported in cached trials |
| Toxic optic neuropathy | 105 | 229.1 183.8–285.5ROR 229.9 · calibrated p 2e-10 ✓ | 167.5 EB05 142.3 · IC025 +6.3 3/3 methods agree | Labeled (related wording) related wording | serious n=105 · 93% clinician | not reported in cached trials |
| Mycobacterial peritonitis | 22 | 210.4 130.6–338.9ROR 210.6 · calibrated p 2e-9 ✓ | 142.2 EB05 99.0 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=22 | not reported in cached trials |
| Choroiditis | 84 | 204.3 160.3–260.5ROR 204.9 · calibrated p 6e-10 ✓ | 152.9 EB05 127.3 · IC025 +6.0 3/3 methods agree | Not in label — unassessed | serious n=84 · ♀ 0% (drug 44%) | not reported in cached trials |
| Sideroblastic anaemia | 26 | 159.2 104.0–243.8ROR 159.4 · calibrated p 1e-8 ✓ | 118.7 EB05 85.1 · IC025 +4.6 3/3 methods agree | Labeled adverse reaction exact term | serious n=23 · 100% clinician | not reported in cached trials |
| Geotrichum infection | 37 | 149.3 104.7–212.9ROR 149.5 · calibrated p 1e-8 ✓ | 115.9 EB05 87.9 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious n=37 · 100% clinician | not reported in cached trials |
| Antimicrobial susceptibility test resistant | 54 | 148.4 110.7–199.1ROR 148.7 · calibrated p 1e-8 ✓ | 117.6 EB05 93.5 · IC025 +5.4 3/3 methods agree | Labeled (related wording) related wording | serious n=52 · ♀ 0% (drug 44%) | not reported in cached trials |
| Trichoglossia | 65 | 133.5 102.4–174.0ROR 133.8 · calibrated p 2e-8 ✓ | 108.7 EB05 88.3 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=25 · 100% clinician | not reported in cached trials |
| Pulmonary interstitial emphysema syndrome | 22 | 129.1 81.9–203.4ROR 129.2 · calibrated p 7e-8 ✓ | 99.9 EB05 69.5 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=22 · ♀ 0% (drug 44%) · 100% clinician | not reported in cached trials |
| Alveolar lung disease | 26 | 111.4 73.6–168.4ROR 111.5 · calibrated p 2e-7 ✓ | 90.0 EB05 64.5 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=26 · ♀ 0% (drug 44%) · 92% clinician | not reported in cached trials |
| Mycobacterium fortuitum infection | 24 | 105.4 68.6–161.8ROR 105.5 · calibrated p 3e-7 ✓ | 85.6 EB05 60.6 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=24 | not reported in cached trials |
| Mycobacterium abscessus infection | 88 | 101.0 80.8–126.3ROR 101.3 · calibrated p 1e-7 ✓ | 86.8 EB05 72.6 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=88 · ♀ 72% (drug 44%) · 95% clinician | not reported in cached trials |
| Antibiotic level above therapeutic | 45 | 89.8 65.8–122.4ROR 89.9 · calibrated p 5e-7 ✓ | 77.1 EB05 60.0 · IC025 +4.9 3/3 methods agree | Lab value / disease marker | serious n=45 · 100% clinician | not reported in cached trials |
| Optic neuropathy | 234 | 89.0 77.7–101.9ROR 89.7 · calibrated p 3e-7 ✓ | 78.5 EB05 70.5 · IC025 +5.9 3/3 methods agree | Labeled adverse reaction exact term | serious n=232 · 95% clinician | not reported in cached trials |
| Mitochondrial toxicity | 88 | 84.9 68.0–105.8ROR 85.1 · calibrated p 5e-7 ✓ | 74.6 EB05 62.4 · IC025 +5.4 3/3 methods agree | Not in label — unassessed | serious n=88 · 100% clinician | not reported in cached trials |
| Papillitis | 17 | 79.7 48.2–131.5ROR 79.7 · calibrated p 2e-6 ✓ | 66.5 EB05 44.0 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=14 | not reported in cached trials |
| Cutaneous mucormycosis | 16 | 69.8 41.8–116.7ROR 69.9 · calibrated p 6e-6 ✓ | 59.3 EB05 38.7 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=16 | not reported in cached trials |
| Immune reconstitution inflammatory syndrome associated tuberculosis | 28 | 64.9 44.1–95.6ROR 65.0 · calibrated p 5e-6 ✓ | 57.3 EB05 41.6 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=28 · 100% clinician | not reported in cached trials |
| Skin candida | 39 | 57.8 41.7–80.1ROR 57.9 · calibrated p 9e-6 ✓ | 52.2 EB05 39.8 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=39 · ♀ 100% (drug 44%) · 100% clinician | NCT00084266: 1/597 (0.2%) on Linezolid |
| Dehiscence | 14 | 56.5 32.8–97.4ROR 56.5 · calibrated p 2e-5 ✓ | 49.1 EB05 31.1 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=14 | NCT00084266: 1/597 (0.2%) on Linezolid (serious AE) |
| Disseminated mycobacterium avium complex infection | 15 | 53.7 31.8–90.8ROR 53.7 · calibrated p 3e-5 ✓ | 47.1 EB05 30.3 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=15 | not reported in cached trials |
| Mycobacterium chelonae infection | 50 | 51.6 38.7–68.7ROR 51.6 · calibrated p 2e-5 ✓ | 47.3 EB05 37.3 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=47 · 100% clinician | not reported in cached trials |
| Ototoxicity | 122 | 49.9 41.5–59.9ROR 50.1 · calibrated p 2e-5 ✓ | 46.3 EB05 39.8 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious n=122 · 96% clinician | not reported in cached trials |
| Hyperlactacidaemia | 166 | 47.5 40.6–55.6ROR 47.8 · calibrated p 2e-5 ✓ | 44.4 EB05 39.0 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious n=164 · 97% clinician | NCT00084266: 1/597 (0.2%) on Linezolid |
| Acid base balance abnormal | 14 | 46.5 27.1–79.9ROR 46.6 · calibrated p 7e-5 ✓ | 41.4 EB05 26.2 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | serious n=14 | NCT00084266: 1/597 (0.2%) on Linezolid |
| Meningitis tuberculous | 33 | 44.1 31.0–62.6ROR 44.1 · calibrated p 5e-5 ✓ | 40.6 EB05 30.3 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=33 · 100% clinician | not reported in cached trials |
| Cardiac valve vegetation | 28 | 43.7 29.9–64.1ROR 43.8 · calibrated p 6e-5 ✓ | 40.2 EB05 29.2 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=28 · ♀ 0% (drug 44%) · 100% clinician | not reported in cached trials |
| Bicytopenia | 109 | 42.2 34.8–51.2ROR 42.4 · calibrated p 4e-5 ✓ | 39.6 EB05 33.8 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious n=109 · 97% clinician | not reported in cached trials |
| Cns ventriculitis | 18 | 41.2 25.6–66.3ROR 41.2 · calibrated p 1e-4 ✓ | 37.5 EB05 25.1 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=18 | not reported in cached trials |
| Dysbiosis | 41 | 38.2 27.9–52.3ROR 38.2 · calibrated p 1e-4 ✓ | 35.7 EB05 27.4 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=41 | not reported in cached trials |
| Pulmonary mucormycosis | 26 | 37.6 25.3–55.8ROR 37.6 · calibrated p 1e-4 ✓ | 34.9 EB05 25.0 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=26 · ♀ 0% (drug 44%) · 100% clinician | not reported in cached trials |
| Serotonin syndrome | 917 | 35.6 33.4–38.1ROR 36.8 · calibrated p 9e-5 ✓ | 33.9 EB05 32.1 · IC025 +5.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 21.5 · 95% clinician | not reported in cached trials |
| Pancreatitis haemorrhagic | 21 | 33.3 21.5–51.6ROR 33.3 · calibrated p 3e-4 ✓ | 31.0 EB05 21.4 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=21 | not reported in cached trials |
| Enterococcal infection | 209 | 31.9 27.8–36.7ROR 32.1 · calibrated p 2e-4 ✓ | 30.5 EB05 27.2 · IC025 +4.6 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=207 · 96% clinician | NCT00084266: 1/587 (0.2%) on Linezolid |
| Enterococcus test positive | 28 | 31.7 21.7–46.3ROR 31.8 · calibrated p 3e-4 ✓ | 29.8 EB05 21.7 · IC025 +3.7 3/3 methods agree | Likely indication confounding term in indications | serious n=28 · ♀ 0% (drug 44%) · 100% clinician | not reported in cached trials |
| Enterococcal bacteraemia | 45 | 31.5 23.4–42.5ROR 31.6 · calibrated p 3e-4 ✓ | 29.9 EB05 23.2 · IC025 +4.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=44 · ♀ 68% (drug 44%) | NCT00084266: 1/587 (0.2%) on Linezolid |
| Herpes zoster meningoencephalitis | 15 | 30.7 18.3–51.5ROR 30.7 · calibrated p 5e-4 ✓ | 28.5 EB05 18.3 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=15 | not reported in cached trials |
| Toxic neuropathy | 16 | 30.1 18.3–49.7ROR 30.1 · calibrated p 6e-4 ✓ | 28.0 EB05 18.3 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | serious n=16 | not reported in cached trials |
| Nocardiosis | 104 | 29.9 24.6–36.4ROR 30.0 · calibrated p 3e-4 ✓ | 28.6 EB05 24.3 · IC025 +4.3 3/3 methods agree | Labeled (related wording) related wording | serious n=104 · 100% clinician | not reported in cached trials |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Linezolid as a study intervention. The right-hand column of the signal table shows whether each FAERS term was also recorded in these trials, with a real denominator (6 of 40 signal terms matched).
- NCT00084266 — Nosocomial Pneumonia With Suspected Or Proven Methicillin-Resistant Staphylococcus Aureus (MRSA) (N=1225, PHASE4; 761 AE terms posted; arms: Linezolid; Vancomycin)
Caveats: trial populations, doses and follow-up differ from the reporting population; AE terms are sponsor-coded and matched here by wording; absence from a trial list means the term was not reported above the sponsor's frequency threshold, not that it cannot occur.
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 |
|---|---|---|---|---|---|---|
| Off label use (used outside approved label) | 2,586 | 2.1 2.0–2.2ROR 2.2 · calibrated p 0.941 | 2.1 EB05 2.0 · IC025 +1.0 3/3 methods agree | Reporting / coding artifact | serious PRR 2.3 | not reported in cached trials |
| Thrombocytopenia (low platelets) | 2,199 | 14.2 13.7–14.8ROR 15.3 · calibrated p 0.006 ✓ | 14.0 EB05 13.5 · IC025 +3.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.9 · 97% clinician | NCT00084266: 1/597 (0.2%) on Linezolid (serious AE) |
| Drug ineffective (drug did not work) | 2,091 | 1.1 1.1–1.2ROR 1.1 · calibrated p 0.396 | 1.1 EB05 1.1 · IC025 +0.1 | Reporting / coding artifact | serious PRR 1.9 | NCT00084266: 1/597 (0.2%) on Linezolid (serious AE) |
| Anaemia (low red blood cells) | 1,716 | 6.4 6.1–6.7ROR 6.8 · calibrated p 0.109 | 6.4 EB05 6.1 · IC025 +2.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.2 · 91% clinician | NCT00084266: 2/587 (0.3%) on Linezolid (serious AE) |
| Drug interaction | 1,435 | 6.5 6.1–6.8ROR 6.7 · calibrated p 0.110 | 6.4 EB05 6.1 · IC025 +2.6 3/3 methods agree | Reporting / coding artifact | serious PRR 4.2 · 94% clinician | not reported in cached trials |
| Nausea | 1,412 | 1.3 1.2–1.3ROR 1.3 · calibrated p 0.496 | 1.3 EB05 1.2 · IC025 +0.3 | Labeled adverse reaction exact term | serious PRR 1.3 | NCT00084266: 1/587 (0.2%) on Linezolid (serious AE) |
| Vomiting | 1,131 | 1.7 1.6–1.8ROR 1.7 · calibrated p 0.793 | 1.7 EB05 1.6 · IC025 +0.7 | Labeled adverse reaction exact term | serious PRR 1.4 | NCT00084266: 1/587 (0.2%) on Linezolid (serious AE) |
| Platelet count decreased | 1,061 | 7.1 6.7–7.6ROR 7.3 · calibrated p 0.086 | 7.0 EB05 6.7 · IC025 +2.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.2 | NCT00084266: 2/597 (0.3%) on Linezolid |
| Diarrhoea (diarrhea) | 1,053 | 1.2 1.1–1.2ROR 1.2 · calibrated p 0.417 | 1.2 EB05 1.1 · IC025 +0.1 | Labeled adverse reaction exact term | serious PRR 1.1 | NCT00084266: 1/587 (0.2%) on Linezolid (serious AE) |
| Pyrexia (fever) | 1,022 | 2.1 2.0–2.2ROR 2.1 · calibrated p 0.985 | 2.1 EB05 2.0 · IC025 +1.0 | Not in label — unassessed | serious PRR 1.6 | NCT00084266: 2/597 (0.3%) on Linezolid (serious AE) |
| Lactic acidosis | 1,018 | 23.2 21.8–24.7ROR 24.0 · calibrated p 8e-4 ✓ | 22.5 EB05 21.3 · IC025 +4.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 14.3 · 98% clinician | not reported in cached trials |
| Neuropathy peripheral (nerve damage in hands/feet) | 989 | 7.5 7.0–8.0ROR 7.7 · calibrated p 0.075 | 7.4 EB05 7.0 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.3 · 91% clinician | not reported in cached trials |
| Acute kidney injury (sudden kidney damage) | 931 | 4.4 4.1–4.6ROR 4.5 · calibrated p 0.302 | 4.3 EB05 4.1 · IC025 +2.0 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.7 · 95% clinician | not reported in cached trials |
| Serotonin syndrome | 917 | 35.6 33.4–38.1ROR 36.8 · calibrated p 9e-5 ✓ | 33.9 EB05 32.1 · IC025 +5.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 21.5 · 95% clinician | not reported in cached trials |
| Pancytopenia (all blood cells low) | 904 | 11.7 10.9–12.4ROR 12.0 · calibrated p 0.017 ✓ | 11.5 EB05 10.9 · IC025 +3.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.3 · 98% clinician | NCT00084266: 2/597 (0.3%) on Linezolid |
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.
- Mycobacterial peritonitis — n=22, PRR 210.4
- Choroiditis — n=84, PRR 204.3
- Geotrichum infection — n=37, PRR 149.3
- Trichoglossia — n=65, PRR 133.5
- Pulmonary interstitial emphysema syndrome — n=22, PRR 129.1
- Alveolar lung disease — n=26, PRR 111.4
- Mycobacterium fortuitum infection — n=24, PRR 105.4
- Mycobacterium abscessus infection — n=88, PRR 101.0
- Mitochondrial toxicity — n=88, PRR 84.9
- Immune reconstitution inflammatory syndrome associated tuberculosis — n=28, PRR 64.9
✓ A hand-written Bradford Hill causality assessment exists for this drug: Linezolid ↔ Thrombocytopenia.
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 Linezolid?
In FDA FAERS, the most frequently co-reported reaction terms for Linezolid are thrombocytopenia, anaemia, nausea, vomiting, platelet count decreased, diarrhoea. 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 Linezolid have an FDA boxed warning?
No. The FDA label retrieved for Linezolid has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Linezolid 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 3d630d3d-510d-43a4-8703-8b6234831564, effective 20260903; matched on
openfda.generic_name.exact:"LINEZOLID") - 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, 1,171 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 - ClinicalTrials.gov API v2 (query
LINEZOLID, results-bearing studies sorted by enrollment)
Page generated 2026-10-14. 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.