Drug · FAERS side-effect profile with label screen
Naproxen side effects: what 78,082 FDA adverse event reports show
Drug class
Nonsteroidal Anti-inflammatory Drug
FDA label (Established Pharmacologic Class) · compare the class
Who reports
78,082 reports · 80% serious · 7,991 with death outcome · 67% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Naproxen tablets and naproxen sodium tablets are indicated for: the relief of the signs and symptoms of: • rheumatoid arthritis • osteoarthritis • ankylosing spondylitis • Polyarticular Juvenile Idiopathic Arthritis Naproxen tablets and naproxen sodium.
FDA label, Indications and Usage
What it is
Naproxen is a methoxynaphthalene that is 2-methoxynaphthalene substituted by a carboxy ethyl group at position 6. Naproxen is a non-steroidal anti-inflammatory drug commonly used for the reduction of pain, fever, inflammation and stiffness caused by conditions such as osteoarthritis, kidney stones, rheumatoid...
PubChem CID 156391 (ChEBI)
Boxed warning
RISK OF SERIOUS CARDIOVASCULAR AND GASTROINTESTINAL EVENTS Cardiovascular Thrombotic Events • Nonsteroidal anti-inflammatory drugs (NSAIDs) cause an increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal.
FDA 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 — boxed warning 1Labeled (related wording) 3Likely indication confounding 2Reporting / coding artifact 2Lab value / disease marker 10Not in label — unassessed 22
What the badges mean
- Labeled — boxed warning The term (or its clinical synonym) appears in the FDA boxed warning: causality is regulator-recognised and considered serious.
- 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, 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). 1,166 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 |
|---|---|---|---|---|---|---|
| Synovial fluid analysis | 65 | 817.1 499.6–1,336.3ROR 817.8 · calibrated p 9e-15 ✓ | 189.2 EB05 153.7 · IC025 +5.9 3/3 methods agree vs other NSAIDs: PRR 48.2 (34.2–68.1) | Reporting / coding artifact | serious n=65 · ♀ 100% (drug 67%) · 100% clinician | not reported in cached trials |
| Cardiospasm | 394 | 662.5 550.7–797.0ROR 665.8 · calibrated p 4e-15 ✓ | 187.8 EB05 172.7 · IC025 +7.1 3/3 methods agree vs other NSAIDs: PRR 47.2 (41.1–54.3) | Not in label — unassessed | serious n=394 | not reported in cached trials |
| Human antichimeric antibody positive | 218 | 491.9 393.0–615.7ROR 493.2 · calibrated p 1e-13 ✓ | 169.9 EB05 151.8 · IC025 +6.7 3/3 methods agree vs other NSAIDs: PRR 41.7 (34.8–50.1) | Lab value / disease marker | serious n=218 · ♀ 100% (drug 67%) | not reported in cached trials |
| Immunisation | 256 | 392.9 323.9–476.6ROR 394.2 · calibrated p 1e-12 ✓ | 156.7 EB05 141.2 · IC025 +6.7 3/3 methods agree vs other NSAIDs: PRR 47.5 (40.0–56.4) | Not in label — unassessed | serious n=256 | not reported in cached trials |
| Hepatic enzyme | 81 | 375.1 267.3–526.4ROR 375.5 · calibrated p 4e-12 ✓ | 150.1 EB05 124.6 · IC025 +6.0 3/3 methods agree vs other NSAIDs: only this drug | Labeled (related wording) related wording | serious n=81 · ♀ 100% (drug 67%) · 100% clinician | NCT00346216: 1/7,933 (0.0%) on Naproxen (serious AE) |
| Palmoplantar keratoderma | 381 | 304.8 263.1–353.1ROR 306.3 · calibrated p 1e-11 ✓ | 141.0 EB05 129.5 · IC025 +6.7 3/3 methods agree vs other NSAIDs: PRR 47.2 (41.0–54.4) | Not in label — unassessed | serious n=381 | not reported in cached trials |
| Congenital hiatus hernia | 105 | 243.1 186.5–316.9ROR 243.5 · calibrated p 1e-10 ✓ | 124.2 EB05 105.5 · IC025 +6.0 3/3 methods agree vs other NSAIDs: PRR 40.5 (31.3–52.6) | Not in label — unassessed | serious n=105 · ♀ 0% (drug 67%) · 100% clinician | not reported in cached trials |
| Red blood cell sedimentation rate | 116 | 189.0 148.9–239.9ROR 189.3 · calibrated p 1e-9 ✓ | 108.6 EB05 93.0 · IC025 +5.9 3/3 methods agree vs other NSAIDs: PRR 47.1 (36.4–60.8) | Lab value / disease marker | serious n=116 · ♀ 100% (drug 67%) · 100% clinician | not reported in cached trials |
| Subcutaneous drug absorption impaired | 223 | 186.9 157.4–221.8ROR 187.4 · calibrated p 9e-10 ✓ | 108.8 EB05 97.4 · IC025 +6.2 3/3 methods agree vs other NSAIDs: PRR 7.4 (6.4–8.5) | Not in label — unassessed | serious n=223 · ♀ 100% (drug 67%) · 100% clinician | not reported in cached trials |
| Hypocholesterolaemia | 111 | 151.8 120.2–191.7ROR 152.0 · calibrated p 6e-9 ✓ | 95.2 EB05 81.2 · IC025 +5.8 3/3 methods agree vs other NSAIDs: PRR 41.8 (32.4–54.0) | Not in label — unassessed | serious n=111 · ♀ 100% (drug 67%) · 100% clinician | not reported in cached trials |
| Body height below normal | 223 | 140.5 119.4–165.3ROR 140.9 · calibrated p 9e-9 ✓ | 91.3 EB05 81.7 · IC025 +6.0 3/3 methods agree vs other NSAIDs: PRR 41.9 (35.0–50.1) | Reporting / coding artifact | serious n=223 · ♀ 100% (drug 67%) | not reported in cached trials |
| Facet joint syndrome | 1,009 | 126.7 117.5–136.5ROR 128.3 · calibrated p 2e-8 ✓ | 85.8 EB05 81.4 · IC025 +6.3 3/3 methods agree vs other NSAIDs: PRR 5.3 (5.0–5.6) | Not in label — unassessed | serious n=1,008 · ♀ 100% (drug 67%) · 95% clinician | NCT00346216: 1/7,933 (0.0%) on Naproxen (serious AE) |
| Rheumatic fever | 1,143 | 95.2 89.0–101.8ROR 96.6 · calibrated p 1e-7 ✓ | 70.2 EB05 66.8 · IC025 +6.0 3/3 methods agree vs other NSAIDs: PRR 4.0 (3.7–4.2) | Likely indication confounding shares a disease stem with the indications wording | serious n=1,143 · ♀ 100% (drug 67%) · 95% clinician | not reported in cached trials |
| Lupus vulgaris | 298 | 89.7 78.7–102.3ROR 90.0 · calibrated p 3e-7 ✓ | 66.9 EB05 60.8 · IC025 +5.7 3/3 methods agree vs other NSAIDs: PRR 3.2 (2.9–3.6) | Not in label — unassessed | serious n=298 · ♀ 100% (drug 67%) · 93% clinician | not reported in cached trials |
| C-reactive protein abnormal | 1,485 | 81.0 76.5–85.8ROR 82.6 · calibrated p 5e-7 ✓ | 62.2 EB05 59.6 · IC025 +5.8 3/3 methods agree vs other NSAIDs: PRR 5.4 (5.1–5.7) | Lab value / disease marker | serious n=1,484 · ♀ 93% (drug 67%) | not reported in cached trials |
| Dislocation of vertebra | 508 | 79.4 72.0–87.7ROR 80.0 · calibrated p 6e-7 ✓ | 61.2 EB05 56.8 · IC025 +5.7 3/3 methods agree vs other NSAIDs: PRR 4.0 (3.6–4.4) | Not in label — unassessed | serious n=508 · ♀ 100% (drug 67%) · 93% clinician | not reported in cached trials |
| Anti-cyclic citrullinated peptide antibody positive | 1,573 | 76.3 72.2–80.7ROR 77.9 · calibrated p 7e-7 ✓ | 59.4 EB05 57.0 · IC025 +5.8 3/3 methods agree vs other NSAIDs: PRR 3.3 (3.1–3.5) | Lab value / disease marker | serious PRR 43.0 · ♀ 99% (drug 67%) · 93% clinician | not reported in cached trials |
| Joint laxity | 67 | 76.2 58.1–100.0ROR 76.3 · calibrated p 1e-6 ✓ | 58.4 EB05 47.6 · IC025 +5.0 3/3 methods agree vs other NSAIDs: PRR 22.9 (17.1–30.6) | Not in label — unassessed | serious n=67 · ♀ 100% (drug 67%) · 100% clinician | not reported in cached trials |
| Swollen joint count increased | 675 | 74.1 68.1–80.7ROR 74.8 · calibrated p 1e-6 ✓ | 58.0 EB05 54.4 · IC025 +5.7 3/3 methods agree vs other NSAIDs: PRR 3.1 (2.9–3.3) | Lab value / disease marker | serious n=674 · ♀ 100% (drug 67%) · 94% clinician | not reported in cached trials |
| Red blood cell sedimentation rate abnormal | 491 | 71.8 65.0–79.3ROR 72.2 · calibrated p 1e-6 ✓ | 56.5 EB05 52.5 · IC025 +5.6 3/3 methods agree vs other NSAIDs: PRR 22.5 (20.2–25.0) | Lab value / disease marker | serious n=491 · ♀ 100% (drug 67%) | not reported in cached trials |
| Peripheral venous disease | 837 | 71.2 66.0–76.8ROR 71.9 · calibrated p 1e-6 ✓ | 56.2 EB05 53.1 · IC025 +5.7 3/3 methods agree vs other NSAIDs: PRR 5.2 (4.9–5.6) | Not in label — unassessed | serious n=836 · ♀ 100% (drug 67%) · 96% clinician | NCT00346216: 1/7,992 (0.0%) on Naproxen (serious AE) |
| Duodenal ulcer perforation | 1,462 | 66.7 63.0–70.6ROR 68.0 · calibrated p 2e-6 ✓ | 53.4 EB05 51.2 · IC025 +5.6 3/3 methods agree vs other NSAIDs: PRR 2.8 (2.7–3.0) | Labeled — boxed warning synonym match | serious PRR 38.5 · ♀ 98% (drug 67%) · 94% clinician | NCT00346216: 2/7,933 (0.0%) on Naproxen (serious AE) |
| Adjustment disorder with depressed mood | 394 | 65.2 58.4–72.7ROR 65.5 · calibrated p 2e-6 ✓ | 52.3 EB05 48.1 · IC025 +5.5 3/3 methods agree vs other NSAIDs: PRR 3.0 (2.7–3.3) | Not in label — unassessed | serious n=393 · ♀ 100% (drug 67%) · 95% clinician | not reported in cached trials |
| C-reactive protein | 177 | 65.0 55.1–76.6ROR 65.1 · calibrated p 3e-6 ✓ | 52.1 EB05 45.9 · IC025 +5.3 3/3 methods agree vs other NSAIDs: PRR 2.3 (2.0–2.7) | Lab value / disease marker | serious n=177 · ♀ 100% (drug 67%) · 100% clinician | not reported in cached trials |
| Ankle arthroplasty | 69 | 63.9 49.1–83.1ROR 64.0 · calibrated p 4e-6 ✓ | 51.0 EB05 41.6 · IC025 +4.8 3/3 methods agree vs other NSAIDs: only this drug | Not in label — unassessed | serious n=69 · ♀ 100% (drug 67%) · 100% clinician | not reported in cached trials |
| Atrial tachycardia | 396 | 62.0 55.6–69.2ROR 62.3 · calibrated p 3e-6 ✓ | 50.3 EB05 46.3 · IC025 +5.4 3/3 methods agree vs other NSAIDs: PRR 46.9 (40.8–53.9) | Not in label — unassessed | serious n=396 | NCT03161093: 1/554 (0.2%) on Naproxen (serious AE) |
| Granuloma skin | 154 | 61.2 51.4–72.9ROR 61.3 · calibrated p 4e-6 ✓ | 49.6 EB05 43.4 · IC025 +5.2 3/3 methods agree vs other NSAIDs: PRR 8.0 (6.7–9.4) | Not in label — unassessed | serious n=153 · ♀ 100% (drug 67%) | not reported in cached trials |
| X-ray abnormal | 328 | 60.4 53.6–68.1ROR 60.6 · calibrated p 4e-6 ✓ | 49.2 EB05 44.9 · IC025 +5.3 3/3 methods agree vs other NSAIDs: PRR 3.2 (2.9–3.6) | Lab value / disease marker | serious n=328 · ♀ 100% (drug 67%) · 100% clinician | not reported in cached trials |
| Joint destruction | 285 | 59.8 52.6–67.9ROR 60.0 · calibrated p 5e-6 ✓ | 48.8 EB05 44.2 · IC025 +5.3 3/3 methods agree vs other NSAIDs: PRR 23.3 (20.2–26.8) | Not in label — unassessed | serious n=285 · ♀ 100% (drug 67%) · 92% clinician | not reported in cached trials |
| Synovial disorder | 80 | 57.1 44.8–72.7ROR 57.1 · calibrated p 8e-6 ✓ | 46.6 EB05 38.7 · IC025 +4.8 3/3 methods agree vs other NSAIDs: PRR 135.7 (88.2–208.6) | Not in label — unassessed | serious n=79 · ♀ 100% (drug 67%) | NCT00346216: 2/7,933 (0.0%) on Naproxen (serious AE) |
| Onychomadesis | 729 | 57.1 52.7–61.8ROR 57.6 · calibrated p 6e-6 ✓ | 47.0 EB05 44.3 · IC025 +5.4 3/3 methods agree vs other NSAIDs: PRR 15.7 (14.5–17.1) | Not in label — unassessed | serious n=727 · ♀ 100% (drug 67%) · 94% clinician | not reported in cached trials |
| Deep vein thrombosis postoperative | 343 | 56.8 50.6–63.9ROR 57.1 · calibrated p 6e-6 ✓ | 46.8 EB05 42.8 · IC025 +5.3 3/3 methods agree vs other NSAIDs: PRR 2.1 (1.9–2.3) | Not in label — unassessed | serious n=343 · ♀ 100% (drug 67%) · 92% clinician | NCT03161093: 1/352 (0.3%) control (serious AE) |
| Anti-cyclic citrullinated peptide antibody | 114 | 55.2 45.1–67.6ROR 55.3 · calibrated p 9e-6 ✓ | 45.5 EB05 38.9 · IC025 +5.0 3/3 methods agree vs other NSAIDs: PRR 2.1 (1.7–2.5) | Lab value / disease marker | serious n=114 · ♀ 100% (drug 67%) · 100% clinician | not reported in cached trials |
| Pruritus genital | 396 | 54.9 49.3–61.2ROR 55.2 · calibrated p 8e-6 ✓ | 45.6 EB05 41.9 · IC025 +5.3 3/3 methods agree vs other NSAIDs: PRR 45.4 (39.6–52.1) | Labeled (related wording) related wording | serious n=395 | not reported in cached trials |
| Synovitis | 3,014 | 53.8 51.7–55.9ROR 55.9 · calibrated p 7e-6 ✓ | 44.8 EB05 43.5 · IC025 +5.4 3/3 methods agree vs other NSAIDs: PRR 4.6 (4.5–4.8) | Not in label — unassessed | serious PRR 33.8 · ♀ 94% (drug 67%) | NCT00346216: 1/8,030 (0.0%) on Naproxen (serious AE) |
| Seronegative arthritis | 182 | 51.9 44.3–60.8ROR 52.0 · calibrated p 1e-5 ✓ | 43.3 EB05 38.3 · IC025 +5.0 3/3 methods agree vs other NSAIDs: PRR 5.6 (4.8–6.5) | Likely indication confounding shares a disease stem with the indications wording | serious n=181 · 100% clinician | not reported in cached trials |
| Tenosynovitis stenosans | 90 | 51.4 41.0–64.4ROR 51.5 · calibrated p 1e-5 ✓ | 42.8 EB05 35.9 · IC025 +4.8 3/3 methods agree vs other NSAIDs: PRR 23.9 (18.5–30.7) | Not in label — unassessed | serious n=90 · ♀ 100% (drug 67%) · 100% clinician | not reported in cached trials |
| Enthesopathy | 249 | 50.3 43.9–57.5ROR 50.4 · calibrated p 1e-5 ✓ | 42.3 EB05 38.0 · IC025 +5.1 3/3 methods agree vs other NSAIDs: PRR 5.7 (5.0–6.5) | Not in label — unassessed | serious n=243 | not reported in cached trials |
| Rheumatoid factor positive | 900 | 49.5 46.2–53.2ROR 50.1 · calibrated p 1e-5 ✓ | 41.8 EB05 39.6 · IC025 +5.2 3/3 methods agree vs other NSAIDs: PRR 3.0 (2.8–3.2) | Lab value / disease marker | serious n=900 · ♀ 100% (drug 67%) · 94% clinician | not reported in cached trials |
| Muscle injury | 1,202 | 46.0 43.3–48.9ROR 46.7 · calibrated p 2e-5 ✓ | 39.3 EB05 37.5 · IC025 +5.2 3/3 methods agree vs other NSAIDs: PRR 2.5 (2.4–2.6) | Labeled (related wording) related wording | serious PRR 30.7 · ♀ 100% (drug 67%) · 95% clinician | not reported in cached trials |
Clinical concept groups
MedDRA splits one clinical problem across several terms (e.g. "neutropenia", "neutrophil count decreased", "agranulocytosis"), which dilutes term-level signals. These rows count reports with any term in a concept group (an exact union, not a sum), compared with all other drugs. Groups are hand-built and listed in the methods.
| Concept | Reports | PRR 95% CI | Reading |
|---|---|---|---|
| Tendon disorder | 695 | 5.04.6–5.4 | signal |
| Anaphylaxis / angioedema | 1,825 | 4.03.8–4.1 | signal |
| Interstitial lung disease | 1,339 | 3.83.6–4.0 | signal |
| Liver injury | 3,943 | 3.53.4–3.7 | signal |
| Gi bleeding | 2,262 | 3.33.2–3.5 | signal |
| Depression | 3,437 | 3.33.2–3.4 | signal |
| Suicidality | 2,497 | 2.72.6–2.9 | signal |
| Kidney injury | 4,617 | 2.72.7–2.8 | signal |
| Hyperglycaemia / diabetes | 3,340 | 2.62.5–2.7 | signal |
| Serious infection | 6,997 | 2.42.4–2.5 | signal |
| Fall / fracture | 3,097 | 2.22.1–2.3 | signal |
| Rhabdomyolysis / myopathy | 645 | 2.12.0–2.3 | raised |
| Severe cutaneous reaction | 561 | 2.01.9–2.2 | raised |
| Anaemia | 1,971 | 1.81.7–1.8 | raised |
| Venous thromboembolism | 1,408 | 1.81.7–1.8 | raised |
| Opportunistic infection | 876 | 1.71.6–1.8 | raised |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Naproxen 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 (8 of 40 signal terms matched).
- NCT00346216 — Prospective Randomized Evaluation Of Celecoxib Integrated Safety Vs Ibuprofen Or Naproxen (N=24081, PHASE4; 1238 AE terms posted; arms: Celecoxib; Ibuprofen; Naproxen)
- NCT03161093 — A Study to Determine the Safety and the Efficacy of Fasinumab Compared to Placebo and Naproxen for Treatment o (N=3307, PHASE3; 221 AE terms posted; arms: Placebo; Naproxen; Fasinumab 1mg Q8W; Fasinumab 1mg Q4W)
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 |
|---|---|---|---|---|---|---|
| Drug ineffective (drug did not work) | 10,140 | 2.1 2.0–2.1ROR 2.2 · calibrated p 0.933 | 2.1 EB05 2.0 · IC025 +1.0 3/3 methods agree vs other NSAIDs: PRR 2.5 (2.4–2.5) | Reporting / coding artifact | age-adj. PRR 2.4 · serious PRR 3.5 | not reported in cached trials |
| Pain | 9,014 | 4.0 3.9–4.1ROR 4.4 · calibrated p 0.316 | 3.9 EB05 3.9 · IC025 +1.9 3/3 methods agree vs other NSAIDs: PRR 2.7 (2.7–2.8) | Likely indication confounding term in indications; also in warnings | age-adj. PRR 4.1 · serious PRR 4.0 | NCT00346216: 13/7,933 (0.2%) on Naproxen (serious AE) |
| Fatigue (tiredness) | 7,627 | 2.7 2.6–2.7ROR 2.8 · calibrated p 0.683 | 2.6 EB05 2.6 · IC025 +1.4 3/3 methods agree vs other NSAIDs: PRR 2.2 (2.1–2.2) | Labeled adverse reaction exact term | age-adj. PRR 2.5 · serious PRR 3.1 | NCT00346216: 2/7,933 (0.0%) on Naproxen (serious AE) |
| Arthralgia (joint pain) | 7,515 | 4.9 4.8–5.1ROR 5.4 · calibrated p 0.199 | 4.9 EB05 4.8 · IC025 +2.2 3/3 methods agree vs other NSAIDs: PRR 3.0 (2.9–3.0) | Not in label — unassessed | age-adj. PRR 4.4 · serious PRR 5.8 | NCT00346216: 39/7,933 (0.5%) on Naproxen (serious AE) |
| Nausea | 7,339 | 2.5 2.5–2.6ROR 2.7 · calibrated p 0.744 | 2.5 EB05 2.5 · IC025 +1.3 3/3 methods agree vs other NSAIDs: PRR 2.3 (2.3–2.4) | Labeled adverse reaction exact term | age-adj. PRR 2.2 · serious PRR 3.0 | NCT00346216: 6/7,933 (0.1%) on Naproxen (serious AE) |
| Off label use (used outside approved label) | 6,331 | 2.0 1.9–2.0ROR 2.1 · calibrated p 0.972 | 2.0 EB05 1.9 · IC025 +0.9 vs other NSAIDs: PRR 2.6 (2.6–2.7) | Reporting / coding artifact | age-adj. PRR 1.9 · serious PRR 2.4 | not reported in cached trials |
| Headache | 5,970 | 2.6 2.5–2.6ROR 2.7 · calibrated p 0.730 | 2.6 EB05 2.5 · IC025 +1.3 3/3 methods agree vs other NSAIDs: PRR 2.2 (2.1–2.2) | Labeled adverse reaction exact term | age-adj. PRR 2.2 · serious PRR 3.2 | NCT00346216: 4/8,030 (0.0%) on Naproxen (serious AE) |
| Diarrhoea (diarrhea) | 5,621 | 2.4 2.3–2.4ROR 2.5 · calibrated p 0.828 | 2.3 EB05 2.3 · IC025 +1.2 3/3 methods agree vs other NSAIDs: PRR 2.2 (2.2–2.3) | Labeled adverse reaction exact term | age-adj. PRR 2.2 · serious PRR 2.7 | NCT00346216: 5/7,933 (0.1%) on Naproxen (serious AE) |
| Vomiting | 4,967 | 2.9 2.8–2.9ROR 3.0 · calibrated p 0.629 | 2.8 EB05 2.8 · IC025 +1.5 3/3 methods agree vs other NSAIDs: PRR 2.2 (2.2–2.3) | Labeled adverse reaction exact term | age-adj. PRR 2.5 · serious PRR 2.8 | NCT00346216: 7/7,933 (0.1%) on Naproxen (serious AE) |
| Dizziness | 4,958 | 2.7 2.6–2.8ROR 2.8 · calibrated p 0.693 | 2.7 EB05 2.6 · IC025 +1.4 3/3 methods agree vs other NSAIDs: PRR 2.3 (2.3–2.4) | Labeled adverse reaction exact term | age-adj. PRR 2.5 · serious PRR 3.0 | NCT00346216: 6/7,933 (0.1%) on Naproxen (serious AE) |
| Rash | 4,852 | 3.0 2.9–3.1ROR 3.2 · calibrated p 0.576 | 3.0 EB05 2.9 · IC025 +1.5 3/3 methods agree vs other NSAIDs: PRR 2.5 (2.4–2.5) | Labeled adverse reaction exact term | age-adj. PRR 3.0 · serious PRR 4.3 | NCT00346216: 1/8,030 (0.0%) on Naproxen (serious AE) |
| Dyspnoea (shortness of breath) | 4,811 | 2.3 2.2–2.4ROR 2.4 · calibrated p 0.866 | 2.3 EB05 2.2 · IC025 +1.1 3/3 methods agree vs other NSAIDs: PRR 1.9 (1.8–1.9) | Labeled adverse reaction exact term | age-adj. PRR 2.2 · serious PRR 2.1 | NCT00346216: 24/7,933 (0.3%) on Naproxen (serious AE) |
| Malaise (feeling unwell) | 4,646 | 2.9 2.8–2.9ROR 3.0 · calibrated p 0.634 | 2.8 EB05 2.8 · IC025 +1.5 3/3 methods agree vs other NSAIDs: PRR 2.9 (2.8–3.0) | Labeled adverse reaction exact term | age-adj. PRR 2.9 · serious PRR 3.2 | NCT00346216: 1/7,992 (0.0%) on Naproxen (serious AE) |
| Joint swelling | 4,519 | 10.4 10.1–10.7ROR 11.0 · calibrated p 0.023 ✓ | 10.1 EB05 9.8 · IC025 +3.3 3/3 methods agree vs other NSAIDs: PRR 3.4 (3.3–3.5) | Not in label — unassessed | age-adj. PRR 8.8 · serious PRR 12.0 | NCT00346216: 1/7,933 (0.0%) on Naproxen (serious AE) |
| Rheumatoid arthritis | 4,493 | 11.1 10.8–11.4ROR 11.7 · calibrated p 0.018 ✓ | 10.7 EB05 10.4 · IC025 +3.4 3/3 methods agree vs other NSAIDs: PRR 3.9 (3.8–4.0) | Likely indication confounding term in indications; also in warnings | age-adj. PRR 9.7 · serious PRR 9.2 · ♀ 91% (drug 67%) | NCT00346216: 3/7,933 (0.0%) on Naproxen (serious AE) |
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.
- Cardiospasm — n=394, PRR 662.5
- Immunisation — n=256, PRR 392.9
- Palmoplantar keratoderma — n=381, PRR 304.8
- Congenital hiatus hernia — n=105, PRR 243.1
- Subcutaneous drug absorption impaired — n=223, PRR 186.9
- Hypocholesterolaemia — n=111, PRR 151.8
- Facet joint syndrome — n=1,009, PRR 126.7 (also seen in trial arm)
- Lupus vulgaris — n=298, PRR 89.7
- Dislocation of vertebra — n=508, PRR 79.4
- Joint laxity — n=67, PRR 76.2
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 Naproxen?
In FDA FAERS, the most frequently co-reported reaction terms for Naproxen are pain, fatigue, arthralgia, nausea, headache, 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 Naproxen have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: RISK OF SERIOUS CARDIOVASCULAR AND GASTROINTESTINAL EVENTS Cardiovascular Thrombotic Events • Nonsteroidal anti-inflammatory drugs (NSAIDs) cause an increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal.
Do FAERS signals prove that Naproxen 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 000155a8-709c-44e5-a75f-cd890f3a7caf, effective 20260129; matched on
openfda.generic_name.exact:"NAPROXEN" AND openfda.product_type:"HUMAN PRESCRIPTION DRUG") - PubChem CID 156391 description (ChEBI)
- 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, 1,206 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
NAPROXEN, 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.