Baricitinib side effects: what 9,584 FDA adverse event reports show
Brand names
Olumiant
Who reports
9,584 reports · 69% serious · 877 with death outcome · 67% female
Used for
OLUMIANT ® is a Janus kinase (JAK) inhibitor indicated for: the treatment of adult patients with moderately to severely active rheumatoid arthritis who have had an inadequate response to one or more TNF blockers. ( 1.1 ) Limitations of Use : Not recommended for use in combination with other JAK inhibitors, biologic DMARDs, or with potent immunosuppressants such as azathioprine and cyclosporine.
What it is
OLUMIANT (baricitinib) is a Janus kinase (JAK) inhibitor with the chemical name {1-(ethylsulfonyl)-3-[4-(7 H -pyrrolo[2,3- d ]pyrimidin-4-yl)-1 H -pyrazol-1-yl]azetidin-3-yl}acetonitrile. Baricitinib has an empirical formula of C 16 H 17 N 7 O 2 S and a molecular weight of 371.42.
Boxed warning
SERIOUS INFECTIONS, MORTALITY, MALIGNANCY, MAJOR ADVERSE CARDIOVASCULAR EVENTS (MACE), and THROMBOSIS WARNING: SERIOUS INFECTIONS, MORTALITY, MALIGNANCY, MAJOR ADVERSE CARDIOVASCULAR EVENTS (MACE), and THROMBOSIS See full prescribing information for complete boxed warning.
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 flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 967 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 |
|---|---|---|---|---|---|---|
| Lumbosacral plexopathy | 26 | 1,078.9 674.1–1,726.9ROR 1,081.9 · χ² 17,955 / p <1e-300 | 469.7 EB05 336.9 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious n=26 | no trial data cached |
| Perineal rash | 25 | 567.9 365.7–881.8ROR 569.3 · χ² 10,755 / p <1e-300 | 334.5 EB05 238.3 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=25 | no trial data cached |
| Testicular seminoma (pure) | 12 | 256.4 141.0–466.3ROR 256.7 · χ² 2,505 / p <1e-300 | 168.4 EB05 102.6 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Diverticulitis intestinal perforated | 23 | 165.4 108.3–252.7ROR 165.8 · χ² 3,340 / p <1e-300 | 136.5 EB05 95.8 · IC025 +4.5 3/3 methods agree | Labeled (related wording) related wording | serious n=23 | no trial data cached |
| Spinal cord injury cervical | 17 | 157.4 96.3–257.5ROR 157.7 · χ² 2,319 / p <1e-300 | 126.3 EB05 83.5 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=17 | no trial data cached |
| Immobilisation syndrome | 13 | 143.9 82.1–252.1ROR 144.1 · χ² 1,598 / p <1e-300 | 113.0 EB05 70.3 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=13 | no trial data cached |
| Blood folate decreased | 44 | 141.5 104.4–191.8ROR 142.1 · χ² 5,630 / p <1e-300 | 125.7 EB05 97.5 · IC025 +5.2 3/3 methods agree | Lab value / disease marker | serious n=44 · ♀ 100% (drug 67%) · 91% clinician | no trial data cached |
| Autoinflammatory disease | 10 | 111.2 58.9–209.9ROR 111.3 · χ² 937 / p 5e-206 | 88.5 EB05 51.4 · IC025 +3.1 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=10 | no trial data cached |
| Smoke sensitivity | 10 | 73.9 39.4–138.8ROR 74.0 · χ² 627 / p 1e-138 | 63.3 EB05 36.7 · IC025 +3.0 3/3 methods agree | Labeled (related wording) related wording | serious n=10 | no trial data cached |
| Eczema herpeticum | 13 | 64.3 37.1–111.7ROR 64.4 · χ² 727 / p 2e-160 | 57.5 EB05 35.8 · IC025 +3.3 3/3 methods agree | Labeled adverse reaction exact term | serious n=13 | no trial data cached |
| Alopecia areata | 49 | 62.8 47.3–83.4ROR 63.1 · χ² 2,836 / p <1e-300 | 59.7 EB05 46.9 · IC025 +4.8 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=9 · 80% consumer | no trial data cached |
| Sputum culture positive | 21 | 57.1 37.1–88.1ROR 57.3 · χ² 1,074 / p 6e-236 | 53.2 EB05 36.7 · IC025 +3.9 3/3 methods agree | Lab value / disease marker | serious n=20 · 100% clinician | no trial data cached |
| Anencephaly | 12 | 47.0 26.5–83.2ROR 47.1 · χ² 485 / p 1e-107 | 43.1 EB05 26.3 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Squamous cell carcinoma of lung | 16 | 46.5 28.3–76.2ROR 46.5 · χ² 653 / p 2e-144 | 43.3 EB05 28.3 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=16 | no trial data cached |
| Lymph node tuberculosis | 11 | 32.8 18.1–59.5ROR 32.9 · χ² 304 / p 2e-68 | 30.8 EB05 18.3 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Pneumothorax spontaneous | 10 | 32.6 17.5–60.8ROR 32.6 · χ² 271 / p 3e-61 | 30.4 EB05 17.5 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Post herpetic neuralgia | 19 | 29.3 18.6–46.0ROR 29.3 · χ² 484 / p 1e-107 | 28.2 EB05 19.0 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=19 | no trial data cached |
| Lung adenocarcinoma | 39 | 28.6 20.9–39.2ROR 28.7 · χ² 998 / p 2e-219 | 27.9 EB05 21.3 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=39 · ♀ 45% (drug 67%) | no trial data cached |
| Pneumomediastinum | 23 | 28.6 18.9–43.1ROR 28.6 · χ² 577 / p 1e-127 | 27.6 EB05 19.4 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=23 | no trial data cached |
| Neurogenic bladder | 26 | 27.2 18.5–40.0ROR 27.2 · χ² 622 / p 2e-137 | 26.4 EB05 18.9 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=26 | no trial data cached |
| Thrombocytosis | 43 | 26.1 19.3–35.2ROR 26.2 · χ² 999 / p 1e-219 | 25.5 EB05 19.7 · IC025 +3.8 3/3 methods agree | Labeled adverse reaction exact term | serious n=33 · ♀ 90% (drug 67%) | no trial data cached |
| Pneumonia pseudomonal | 17 | 24.7 15.3–39.9ROR 24.8 · χ² 360 / p 2e-80 | 23.9 EB05 15.7 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=16 | no trial data cached |
| Arthrodesis | 11 | 23.9 13.2–43.3ROR 23.9 · χ² 217 / p 2e-49 | 22.6 EB05 13.1 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Ophthalmic herpes zoster | 19 | 23.5 15.0–36.9ROR 23.5 · χ² 383 / p 1e-85 | 22.8 EB05 15.3 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | serious n=19 | no trial data cached |
| Osteochondrosis | 12 | 22.7 12.8–40.0ROR 22.7 · χ² 225 / p 4e-51 | 21.5 EB05 12.8 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Fibrin d dimer increased | 36 | 22.3 16.1–31.0ROR 22.4 · χ² 705 / p 1e-155 | 21.9 EB05 16.5 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=32 | no trial data cached |
| Pneumonia staphylococcal | 19 | 21.3 13.6–33.4ROR 21.3 · χ² 344 / p 4e-77 | 20.6 EB05 13.8 · IC025 +3.0 3/3 methods agree | Not in label — unassessed | serious n=19 | no trial data cached |
| Peripheral artery occlusion | 13 | 20.5 11.9–35.4ROR 20.5 · χ² 220 / p 4e-50 | 19.5 EB05 11.7 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Cutaneous t-cell lymphoma | 11 | 20.4 11.3–37.0ROR 20.5 · χ² 183 / p 6e-42 | 19.2 EB05 10.8 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Post-acute covid-19 syndrome | 11 | 19.6 10.8–35.5ROR 19.7 · χ² 175 / p 3e-40 | 18.4 EB05 10.2 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Diverticular perforation | 18 | 19.1 12.0–30.4ROR 19.2 · χ² 289 / p 4e-65 | 18.5 EB05 12.1 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious n=17 | no trial data cached |
| Haemophagocytic lymphohistiocytosis | 62 | 18.9 14.8–24.3ROR 19.0 · χ² 1,026 / p 2e-225 | 18.7 EB05 15.1 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 15.6 · 90% clinician | no trial data cached |
| Small cell lung cancer | 12 | 18.1 10.3–31.9ROR 18.1 · χ² 176 / p 2e-40 | 17.0 EB05 9.6 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Covid-19 pneumonia | 96 | 17.8 14.6–21.7ROR 18.0 · χ² 1,494 / p <1e-300 | 17.6 EB05 14.8 · IC025 +3.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 14.4 | no trial data cached |
| Osteoporotic fracture | 15 | 17.2 10.3–28.5ROR 17.2 · χ² 211 / p 5e-48 | 16.3 EB05 9.9 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=15 | no trial data cached |
| Varicella zoster virus infection | 16 | 17.1 10.4–27.9ROR 17.1 · χ² 225 / p 5e-51 | 16.3 EB05 10.1 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious n=15 | no trial data cached |
| Adenocarcinoma of colon | 14 | 16.5 9.7–27.8ROR 16.5 · χ² 187 / p 9e-43 | 15.5 EB05 9.1 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=14 | no trial data cached |
| Stenotrophomonas infection | 10 | 16.4 8.8–30.6ROR 16.5 · χ² 129 / p 3e-30 | 14.8 EB05 7.4 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Bronchopulmonary aspergillosis | 54 | 15.4 11.8–20.1ROR 15.5 · χ² 708 / p 3e-156 | 15.2 EB05 12.0 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 12.5 · ♀ 6% (drug 67%) | no trial data cached |
| Pneumonia legionella | 11 | 15.2 8.4–27.5ROR 15.2 · χ² 131 / p 1e-30 | 13.6 EB05 7.1 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
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) | 752 | 1.2 1.2–1.3ROR 1.3 · χ² 40 / p 1e-10 | 1.2 EB05 1.2 · IC025 +0.2 | Reporting / coding artifact | serious PRR 1.8 | no trial data cached |
| Off label use (used outside approved label) | 687 | 1.7 1.6–1.9ROR 1.8 · χ² 221 / p 3e-50 | 1.7 EB05 1.6 · IC025 +0.7 | Reporting / coding artifact | serious PRR 2.2 · ♀ 42% (drug 67%) | no trial data cached |
| Covid-19 | 449 | 5.6 5.1–6.1ROR 5.8 · χ² 1,686 / p <1e-300 | 5.5 EB05 5.1 · IC025 +2.3 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 6.6 | no trial data cached |
| Rheumatoid arthritis | 355 | 6.9 6.2–7.6ROR 7.1 · χ² 1,785 / p <1e-300 | 6.8 EB05 6.2 · IC025 +2.6 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 5.7 | no trial data cached |
| Pulmonary embolism (lung blood clot) | 309 | 7.1 6.4–7.9ROR 7.3 · χ² 1,616 / p <1e-300 | 7.0 EB05 6.4 · IC025 +2.6 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 5.8 · ♀ 47% (drug 67%) | no trial data cached |
| Pneumonia (lung infection) | 282 | 1.9 1.7–2.1ROR 1.9 · χ² 123 / p 7e-29 | 1.9 EB05 1.7 · IC025 +0.7 | Labeled — boxed warning synonym match | serious PRR 1.4 | no trial data cached |
| Headache | 265 | 0.9 0.8–1.0ROR 0.9 · χ² 2 / p 0.107 | 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 |
| Herpes zoster (shingles) | 239 | 9.1 8.0–10.3ROR 9.3 · χ² 1,717 / p <1e-300 | 9.0 EB05 8.1 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 9.4 | no trial data cached |
| Death | 237 | 0.6 0.5–0.7ROR 0.6 · χ² 65 / p 5e-16 | 0.6 EB05 0.5 · IC025 -0.9 PRR-only: not supported by EBGM or IC | Outcome field, not a reaction boxed warning mentions mortality | serious PRR 0.5 | no trial data cached |
| Nausea | 233 | 0.6 0.6–0.7ROR 0.6 · χ² 47 / p 4e-12 | 0.6 EB05 0.6 · IC025 -0.8 PRR-only: not supported by EBGM or IC | Labeled adverse reaction exact term | serious PRR 0.6 | no trial data cached |
| Deep vein thrombosis (leg blood clot) | 215 | 7.2 6.3–8.2ROR 7.4 · χ² 1,146 / p 2e-251 | 7.1 EB05 6.3 · IC025 +2.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.9 · ♀ 46% (drug 67%) | no trial data cached |
| Fatigue (tiredness) | 187 | 0.5 0.5–0.6ROR 0.5 · χ² 82 / p 6e-20 | 0.5 EB05 0.5 · IC025 -1.2 PRR-only: not supported by EBGM or IC | Labeled adverse reaction exact term | serious PRR 0.5 | no trial data cached |
| Arthralgia (joint pain) | 187 | 1.0 0.9–1.1ROR 1.0 · χ² 0 / p 0.445 | 1.0 EB05 0.9 · IC025 -0.3 PRR-only: not supported by EBGM or IC | Not in label — unassessed | serious PRR 1.0 | no trial data cached |
| Weight increased (weight gain) | 187 | 1.8 1.6–2.1ROR 1.9 · χ² 71 / p 2e-17 | 1.8 EB05 1.6 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 1.6 | no trial data cached |
| Therapy interrupted | 180 | 5.7 4.9–6.6ROR 5.8 · χ² 697 / p 7e-154 | 5.6 EB05 5.0 · IC025 +2.2 3/3 methods agree | Reporting / coding artifact | serious PRR 1.2 · 98% clinician | 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.
- Lumbosacral plexopathy — n=26, PRR 1,078.9
- Perineal rash — n=25, PRR 567.9
- Lung adenocarcinoma — n=39, PRR 28.6
- Pneumomediastinum — n=23, PRR 28.6
- Neurogenic bladder — n=26, PRR 27.2
- Fibrin d dimer increased — n=36, PRR 22.3
- Haemophagocytic lymphohistiocytosis — n=62, PRR 18.9
- Bronchopulmonary aspergillosis — n=54, PRR 15.4
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 Baricitinib?
In FDA FAERS, the most frequently co-reported reaction terms for Baricitinib are covid-19, rheumatoid arthritis, pulmonary embolism, pneumonia, headache, herpes zoster. 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 Baricitinib have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: SERIOUS INFECTIONS, MORTALITY, MALIGNANCY, MAJOR ADVERSE CARDIOVASCULAR EVENTS (MACE), and THROMBOSIS WARNING: SERIOUS INFECTIONS, MORTALITY, MALIGNANCY, MAJOR ADVERSE CARDIOVASCULAR EVENTS (MACE), and THROMBOSIS See full prescribing information for complete boxed warning.
Do FAERS signals prove that Baricitinib 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 866e9f35-9035-4581-a4b1-75a621ab55cf, effective 20260630; matched on
openfda.generic_name.exact:"BARICITINIB") - 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, 1,007 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.