Naproxen Sodium side effects: what 142,029 FDA adverse event reports show
Drug class
Nonsteroidal Anti-inflammatory Drug
Who reports
142,029 reports · 61% serious · 11,472 with death outcome · 68% female
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.
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...
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.
Causality screen of the 40 strongest signals
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). 1,150 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 |
|---|---|---|---|---|---|---|
| Human antichimeric antibody positive | 248 | 412.4 323.1–526.5ROR 413.1 · calibrated p 8e-13 ✓ | 107.0 EB05 96.3 · IC025 +6.3 3/3 methods agree vs other NSAIDs: PRR 54.0 (45.1–64.8) | Lab value / disease marker | serious n=248 · ♀ 100% (drug 68%) | not reported in cached trials |
| Cardiospasm | 396 | 369.6 307.0–445.0ROR 370.7 · calibrated p 2e-12 ✓ | 104.2 EB05 95.9 · IC025 +6.4 3/3 methods agree vs other NSAIDs: PRR 47.7 (41.5–54.8) | Not in label — unassessed | serious n=396 | not reported in cached trials |
| Immunisation | 256 | 215.3 177.5–261.2ROR 215.7 · calibrated p 3e-10 ✓ | 86.6 EB05 78.0 · IC025 +6.0 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 |
| C-reactive protein | 505 | 186.9 163.8–213.2ROR 187.5 · calibrated p 8e-10 ✓ | 81.9 EB05 76.0 · IC025 +6.1 3/3 methods agree vs other NSAIDs: PRR 7.3 (6.6–8.0) | Lab value / disease marker | serious n=505 · ♀ 100% (drug 68%) · 100% clinician | not reported in cached trials |
| Congenital hiatus hernia | 123 | 185.4 141.9–242.1ROR 185.5 · calibrated p 1e-9 ✓ | 80.8 EB05 69.5 · IC025 +5.6 3/3 methods agree vs other NSAIDs: PRR 55.6 (42.9–72.2) | Not in label — unassessed | serious n=123 · ♀ 0% (drug 68%) · 100% clinician | not reported in cached trials |
| Grip strength | 128 | 183.4 141.3–238.0ROR 183.5 · calibrated p 2e-9 ✓ | 80.5 EB05 69.4 · IC025 +5.7 3/3 methods agree vs other NSAIDs: PRR 20.7 (16.9–25.5) | Not in label — unassessed | serious n=128 · ♀ 100% (drug 68%) · 100% clinician | not reported in cached trials |
| Palmoplantar keratoderma | 383 | 168.9 145.8–195.8ROR 169.4 · calibrated p 2e-9 ✓ | 78.2 EB05 71.8 · IC025 +6.0 3/3 methods agree vs other NSAIDs: PRR 47.7 (41.4–55.0) | Not in label — unassessed | serious n=383 | not reported in cached trials |
| Facet joint syndrome | 1,649 | 163.1 152.0–174.9ROR 165.0 · calibrated p 2e-9 ✓ | 77.1 EB05 74.1 · IC025 +6.2 3/3 methods agree vs other NSAIDs: PRR 9.3 (8.8–9.8) | Not in label — unassessed | serious n=1,648 · ♀ 100% (drug 68%) · 95% clinician | NCT00346216: 1/7,933 (0.0%) on Naproxen (serious AE) |
| Lupus vulgaris | 613 | 157.8 140.8–176.9ROR 158.5 · calibrated p 3e-9 ✓ | 75.8 EB05 70.9 · IC025 +6.0 3/3 methods agree vs other NSAIDs: PRR 7.1 (6.5–7.7) | Not in label — unassessed | serious n=613 · ♀ 100% (drug 68%) · 100% clinician | not reported in cached trials |
| Swollen joint count | 124 | 150.8 117.2–193.9ROR 150.9 · calibrated p 7e-9 ✓ | 73.5 EB05 63.3 · IC025 +5.5 3/3 methods agree vs other NSAIDs: PRR 25.6 (20.6–31.8) | Not in label — unassessed | serious n=124 · ♀ 100% (drug 68%) · 100% clinician | not reported in cached trials |
| Deep vein thrombosis postoperative | 984 | 149.5 136.8–163.5ROR 150.6 · calibrated p 5e-9 ✓ | 73.9 EB05 70.1 · IC025 +6.1 3/3 methods agree vs other NSAIDs: PRR 6.5 (6.1–6.9) | Not in label — unassessed | serious n=984 · ♀ 100% (drug 68%) · 95% clinician | NCT03161093: 1/352 (0.3%) control (serious AE) |
| Swollen joint count increased | 1,488 | 135.3 126.1–145.2ROR 136.7 · calibrated p 1e-8 ✓ | 70.3 EB05 67.4 · IC025 +6.0 3/3 methods agree vs other NSAIDs: PRR 7.4 (7.0–7.8) | Lab value / disease marker | serious n=1,487 · ♀ 100% (drug 68%) · 95% clinician | not reported in cached trials |
| Rheumatic fever | 2,066 | 133.1 125.4–141.2ROR 135.0 · calibrated p 1e-8 ✓ | 69.8 EB05 67.3 · IC025 +6.0 3/3 methods agree vs other NSAIDs: PRR 7.7 (7.4–8.0) | Likely indication confounding shares a disease stem with the indications wording | serious n=2,066 · ♀ 100% (drug 68%) · 95% clinician | not reported in cached trials |
| Anti-cyclic citrullinated peptide antibody | 306 | 125.4 107.6–146.1ROR 125.7 · calibrated p 2e-8 ✓ | 67.4 EB05 61.3 · IC025 +5.7 3/3 methods agree vs other NSAIDs: PRR 6.1 (5.4–6.8) | Lab value / disease marker | serious n=306 · ♀ 100% (drug 68%) · 100% clinician | not reported in cached trials |
| Subcutaneous drug absorption impaired | 241 | 117.4 99.1–139.1ROR 117.6 · calibrated p 4e-8 ✓ | 64.9 EB05 58.3 · IC025 +5.6 3/3 methods agree vs other NSAIDs: PRR 8.1 (7.0–9.2) | Not in label — unassessed | serious n=240 · ♀ 100% (drug 68%) · 100% clinician | not reported in cached trials |
| Adjustment disorder with depressed mood | 871 | 112.6 103.1–123.0ROR 113.3 · calibrated p 5e-8 ✓ | 63.7 EB05 60.2 · IC025 +5.8 3/3 methods agree vs other NSAIDs: PRR 7.1 (6.6–7.6) | Not in label — unassessed | serious n=869 · ♀ 100% (drug 68%) · 96% clinician | not reported in cached trials |
| Dislocation of vertebra | 953 | 110.9 102.0–120.7ROR 111.7 · calibrated p 5e-8 ✓ | 63.1 EB05 59.8 · IC025 +5.8 3/3 methods agree vs other NSAIDs: PRR 8.1 (7.6–8.6) | Not in label — unassessed | serious n=953 · ♀ 100% (drug 68%) · 95% clinician | not reported in cached trials |
| Red blood cell sedimentation rate | 117 | 105.1 82.9–133.4ROR 105.2 · calibrated p 1e-7 ✓ | 60.7 EB05 52.0 · IC025 +5.3 3/3 methods agree vs other NSAIDs: PRR 47.9 (37.1–61.9) | Lab value / disease marker | serious n=117 · ♀ 100% (drug 68%) · 100% clinician | not reported in cached trials |
| Hypocholesterolaemia | 126 | 102.4 81.5–128.7ROR 102.5 · calibrated p 1e-7 ✓ | 59.9 EB05 51.6 · IC025 +5.3 3/3 methods agree vs other NSAIDs: PRR 53.9 (41.8–69.6) | Not in label — unassessed | serious n=126 · ♀ 100% (drug 68%) · 100% clinician | not reported in cached trials |
| Body height below normal | 253 | 94.1 80.3–110.2ROR 94.3 · calibrated p 2e-7 ✓ | 57.2 EB05 51.5 · IC025 +5.5 3/3 methods agree vs other NSAIDs: PRR 53.9 (45.0–64.5) | Reporting / coding artifact | serious n=253 · ♀ 100% (drug 68%) | not reported in cached trials |
| X-ray abnormal | 664 | 87.5 79.5–96.3ROR 87.9 · calibrated p 3e-7 ✓ | 54.8 EB05 51.4 · IC025 +5.6 3/3 methods agree vs other NSAIDs: PRR 7.0 (6.5–7.6) | Lab value / disease marker | serious n=664 · ♀ 100% (drug 68%) · 100% clinician | not reported in cached trials |
| C-reactive protein abnormal | 2,280 | 81.6 77.5–85.8ROR 82.9 · calibrated p 5e-7 ✓ | 52.5 EB05 50.7 · IC025 +5.6 3/3 methods agree vs other NSAIDs: PRR 8.8 (8.4–9.2) | Lab value / disease marker | serious n=2,278 · ♀ 95% (drug 68%) | not reported in cached trials |
| Duodenal ulcer perforation | 2,535 | 77.9 74.2–81.7ROR 79.2 · calibrated p 6e-7 ✓ | 50.9 EB05 49.3 · IC025 +5.6 3/3 methods agree vs other NSAIDs: PRR 5.1 (4.9–5.3) | Labeled — boxed warning synonym match | serious PRR 48.1 · ♀ 98% (drug 68%) · 95% clinician | NCT00346216: 2/7,933 (0.0%) on Naproxen (serious AE) |
| Joint laxity | 103 | 76.0 59.9–96.5ROR 76.1 · calibrated p 1e-6 ✓ | 49.7 EB05 42.2 · IC025 +5.0 3/3 methods agree vs other NSAIDs: PRR 47.5 (36.1–62.4) | Not in label — unassessed | serious n=102 · ♀ 100% (drug 68%) · 100% clinician | not reported in cached trials |
| Anti-cyclic citrullinated peptide antibody positive | 2,416 | 76.0 72.4–79.8ROR 77.3 · calibrated p 7e-7 ✓ | 50.2 EB05 48.5 · IC025 +5.6 3/3 methods agree vs other NSAIDs: PRR 5.2 (5.0–5.5) | Lab value / disease marker | serious PRR 47.5 · ♀ 100% (drug 68%) · 93% clinician | not reported in cached trials |
| Rheumatoid factor positive | 1,845 | 69.3 65.6–73.3ROR 70.2 · calibrated p 1e-6 ✓ | 47.2 EB05 45.4 · IC025 +5.5 3/3 methods agree vs other NSAIDs: PRR 6.6 (6.3–6.9) | Lab value / disease marker | serious n=1,844 · ♀ 100% (drug 68%) · 96% clinician | not reported in cached trials |
| Peripheral venous disease | 1,263 | 68.2 63.8–72.9ROR 68.8 · calibrated p 2e-6 ✓ | 46.6 EB05 44.5 · IC025 +5.4 3/3 methods agree vs other NSAIDs: PRR 8.4 (7.9–8.9) | Not in label — unassessed | serious n=1,260 · ♀ 100% (drug 68%) · 95% clinician | NCT00346216: 1/7,992 (0.0%) on Naproxen (serious AE) |
| Seronegative arthritis | 318 | 58.2 51.1–66.3ROR 58.4 · calibrated p 5e-6 ✓ | 41.7 EB05 38.0 · IC025 +5.1 3/3 methods agree vs other NSAIDs: PRR 10.8 (9.5–12.2) | Likely indication confounding shares a disease stem with the indications wording | serious n=317 · ♀ 88% (drug 68%) · 100% clinician | not reported in cached trials |
| Red blood cell sedimentation rate abnormal | 597 | 50.8 46.3–55.8ROR 51.0 · calibrated p 1e-5 ✓ | 37.8 EB05 35.3 · IC025 +5.1 3/3 methods agree vs other NSAIDs: PRR 30.5 (27.5–33.7) | Lab value / disease marker | serious n=596 · ♀ 100% (drug 68%) | not reported in cached trials |
| Retinitis | 426 | 50.4 45.2–56.3ROR 50.6 · calibrated p 1e-5 ✓ | 37.6 EB05 34.7 · IC025 +5.0 3/3 methods agree vs other NSAIDs: PRR 6.6 (5.9–7.3) | Not in label — unassessed | serious n=426 · ♀ 100% (drug 68%) · 100% clinician | not reported in cached trials |
| Helicobacter infection | 2,516 | 48.2 46.1–50.4ROR 49.1 · calibrated p 2e-5 ✓ | 36.4 EB05 35.2 · IC025 +5.1 3/3 methods agree vs other NSAIDs: PRR 5.0 (4.8–5.2) | Not in label — unassessed | serious PRR 36.3 · ♀ 100% (drug 68%) · 94% clinician | not reported in cached trials |
| Muscle injury | 2,008 | 47.7 45.3–50.1ROR 48.3 · calibrated p 2e-5 ✓ | 36.1 EB05 34.8 · IC025 +5.1 3/3 methods agree vs other NSAIDs: PRR 4.3 (4.1–4.5) | Labeled (related wording) related wording | serious PRR 36.8 · ♀ 100% (drug 68%) · 95% clinician | not reported in cached trials |
| Folliculitis | 2,420 | 45.0 43.0–47.1ROR 45.8 · calibrated p 2e-5 ✓ | 34.6 EB05 33.4 · IC025 +5.0 3/3 methods agree vs other NSAIDs: PRR 4.9 (4.7–5.1) | Not in label — unassessed | serious PRR 38.3 · ♀ 100% (drug 68%) · 95% clinician | not reported in cached trials |
| Synovitis | 4,156 | 44.0 42.5–45.6ROR 45.3 · calibrated p 2e-5 ✓ | 34.0 EB05 33.1 · IC025 +5.0 3/3 methods agree vs other NSAIDs: PRR 6.6 (6.4–6.8) | Not in label — unassessed | serious PRR 33.5 · ♀ 95% (drug 68%) | NCT00346216: 1/8,030 (0.0%) on Naproxen (serious AE) |
| Pemphigus | 2,778 | 42.3 40.6–44.2ROR 43.2 · calibrated p 3e-5 ✓ | 33.0 EB05 32.0 · IC025 +5.0 3/3 methods agree vs other NSAIDs: PRR 5.3 (5.1–5.5) | Not in label — unassessed | serious PRR 31.2 · ♀ 100% (drug 68%) · 95% clinician | not reported in cached trials |
| Hand deformity | 2,837 | 40.7 39.1–42.5ROR 41.5 · calibrated p 4e-5 ✓ | 32.0 EB05 31.0 · IC025 +4.9 3/3 methods agree vs other NSAIDs: PRR 5.3 (5.2–5.5) | Not in label — unassessed | serious PRR 32.8 · ♀ 99% (drug 68%) · 94% clinician | not reported in cached trials |
| Breast cancer stage iii | 1,375 | 40.0 37.7–42.4ROR 40.4 · calibrated p 5e-5 ✓ | 31.5 EB05 30.2 · IC025 +4.9 3/3 methods agree vs other NSAIDs: PRR 9.4 (8.9–10.0) | Not in label — unassessed | serious n=1,375 · ♀ 100% (drug 68%) · 94% clinician | NCT00346216: 1/7,933 (0.0%) on Naproxen (serious AE) |
| Porphyria acute | 294 | 39.8 35.0–45.3ROR 39.9 · calibrated p 6e-5 ✓ | 31.4 EB05 28.5 · IC025 +4.7 3/3 methods agree vs other NSAIDs: PRR 7.2 (6.4–8.1) | Labeled (related wording) related wording | serious n=294 · ♀ 100% (drug 68%) · 100% clinician | not reported in cached trials |
| Joint destruction | 316 | 37.2 32.9–42.1ROR 37.3 · calibrated p 8e-5 ✓ | 29.8 EB05 27.1 · IC025 +4.6 3/3 methods agree vs other NSAIDs: PRR 27.2 (23.7–31.3) | Not in label — unassessed | serious n=316 · ♀ 100% (drug 68%) · 100% clinician | not reported in cached trials |
| Onychomadesis | 792 | 34.6 32.1–37.4ROR 34.8 · calibrated p 1e-4 ✓ | 28.1 EB05 26.5 · IC025 +4.7 3/3 methods agree vs other NSAIDs: PRR 17.6 (16.2–19.0) | Not in label — unassessed | serious n=786 · ♀ 100% (drug 68%) · 92% 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 | 876 | 3.43.2–3.7 | signal |
| Interstitial lung disease | 2,001 | 3.13.0–3.3 | signal |
| Gi bleeding | 3,785 | 3.13.0–3.2 | signal |
| Liver injury | 5,885 | 2.92.8–3.0 | signal |
| Anaphylaxis / angioedema | 2,359 | 2.82.7–2.9 | signal |
| Depression | 5,005 | 2.72.6–2.7 | signal |
| Hyperglycaemia / diabetes | 4,909 | 2.12.1–2.2 | signal |
| Kidney injury | 6,032 | 2.01.9–2.0 | raised |
| Serious infection | 10,015 | 1.91.9–2.0 | raised |
| Suicidality | 2,944 | 1.81.7–1.8 | raised |
| Fall / fracture | 4,462 | 1.71.7–1.8 | raised |
| Severe cutaneous reaction | 709 | 1.41.3–1.5 | raised |
| Pancreatitis | 768 | 1.41.3–1.5 | raised |
| Anaemia | 2,793 | 1.41.3–1.4 | raised |
| Myocardial infarction | 1,890 | 1.41.3–1.4 | raised |
| Rhabdomyolysis / myopathy | 743 | 1.41.3–1.5 | 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 (6 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) | 20,260 | 2.3 2.3–2.3ROR 2.5 · calibrated p 0.810 | 2.3 EB05 2.2 · IC025 +1.2 3/3 methods agree vs other NSAIDs: PRR 5.2 (5.2–5.3) | Reporting / coding artifact | age-adj. PRR 2.4 · serious PRR 3.2 | not reported in cached trials |
| Pain | 12,514 | 3.0 3.0–3.1ROR 3.2 · calibrated p 0.553 | 3.0 EB05 3.0 · IC025 +1.6 3/3 methods agree vs other NSAIDs: PRR 3.9 (3.9–4.0) | Likely indication confounding term in indications; also in warnings | age-adj. PRR 3.5 · serious PRR 3.8 | NCT00346216: 13/7,933 (0.2%) on Naproxen (serious AE) |
| Fatigue (tiredness) | 11,626 | 2.2 2.2–2.3ROR 2.3 · calibrated p 0.885 | 2.2 EB05 2.2 · IC025 +1.1 3/3 methods agree vs other NSAIDs: PRR 3.4 (3.4–3.5) | Labeled adverse reaction exact term | age-adj. PRR 2.3 · serious PRR 3.2 | NCT00346216: 2/7,933 (0.0%) on Naproxen (serious AE) |
| Nausea | 10,785 | 2.0 2.0–2.1ROR 2.1 · calibrated p 0.994 | 2.0 EB05 2.0 · IC025 +1.0 vs other NSAIDs: PRR 3.5 (3.4–3.5) | Labeled adverse reaction exact term | age-adj. PRR 2.0 · serious PRR 2.9 | NCT00346216: 6/7,933 (0.1%) on Naproxen (serious AE) |
| Arthralgia (joint pain) | 10,555 | 3.8 3.8–3.9ROR 4.1 · calibrated p 0.366 | 3.8 EB05 3.7 · IC025 +1.9 3/3 methods agree vs other NSAIDs: PRR 4.3 (4.2–4.4) | Not in label — unassessed | age-adj. PRR 3.8 · serious PRR 5.4 | NCT00346216: 39/7,933 (0.5%) on Naproxen (serious AE) |
| Headache | 9,277 | 2.2 2.2–2.2ROR 2.3 · calibrated p 0.908 | 2.2 EB05 2.2 · IC025 +1.1 3/3 methods agree vs other NSAIDs: PRR 3.4 (3.4–3.5) | Labeled adverse reaction exact term | age-adj. PRR 2.1 · serious PRR 3.2 | NCT00346216: 4/8,030 (0.0%) on Naproxen (serious AE) |
| Off label use (used outside approved label) | 8,974 | 1.5 1.5–1.6ROR 1.6 · calibrated p 0.686 | 1.5 EB05 1.5 · IC025 +0.6 vs other NSAIDs: PRR 3.8 (3.8–3.9) | Reporting / coding artifact | age-adj. PRR 1.6 · serious PRR 2.3 | not reported in cached trials |
| Diarrhoea (diarrhea) | 8,574 | 2.0 1.9–2.0ROR 2.0 · calibrated p 0.968 | 2.0 EB05 1.9 · IC025 +0.9 vs other NSAIDs: PRR 3.5 (3.4–3.6) | Labeled adverse reaction exact term | age-adj. PRR 2.0 · serious PRR 2.7 | NCT00346216: 5/7,933 (0.1%) on Naproxen (serious AE) |
| Dizziness | 7,999 | 2.4 2.3–2.4ROR 2.5 · calibrated p 0.823 | 2.4 EB05 2.3 · IC025 +1.2 3/3 methods agree vs other NSAIDs: PRR 3.9 (3.8–4.0) | Labeled adverse reaction exact term | age-adj. PRR 2.4 · serious PRR 3.1 | NCT00346216: 6/7,933 (0.1%) on Naproxen (serious AE) |
| Vomiting | 7,527 | 2.4 2.3–2.4ROR 2.5 · calibrated p 0.826 | 2.4 EB05 2.3 · IC025 +1.2 3/3 methods agree vs other NSAIDs: PRR 3.5 (3.4–3.6) | Labeled adverse reaction exact term | age-adj. PRR 2.3 · serious PRR 2.9 | NCT00346216: 7/7,933 (0.1%) on Naproxen (serious AE) |
| Rash | 7,308 | 2.5 2.5–2.6ROR 2.6 · calibrated p 0.773 | 2.5 EB05 2.4 · IC025 +1.3 3/3 methods agree vs other NSAIDs: PRR 3.8 (3.7–3.9) | Labeled adverse reaction exact term | age-adj. PRR 2.7 · serious PRR 4.3 | NCT00346216: 1/8,030 (0.0%) on Naproxen (serious AE) |
| Dyspnoea (shortness of breath) | 7,152 | 1.9 1.8–1.9ROR 1.9 · calibrated p 0.902 | 1.9 EB05 1.8 · IC025 +0.9 vs other NSAIDs: PRR 2.9 (2.8–2.9) | Labeled adverse reaction exact term | age-adj. PRR 1.9 · serious PRR 2.2 | NCT00346216: 24/7,933 (0.3%) on Naproxen (serious AE) |
| Malaise (feeling unwell) | 6,655 | 2.3 2.2–2.3ROR 2.3 · calibrated p 0.895 | 2.2 EB05 2.2 · IC025 +1.1 3/3 methods agree vs other NSAIDs: PRR 4.2 (4.1–4.3) | Labeled adverse reaction exact term | age-adj. PRR 2.4 · serious PRR 3.1 | NCT00346216: 1/7,992 (0.0%) on Naproxen (serious AE) |
| Pain in extremity | 6,359 | 3.2 3.2–3.3ROR 3.3 · calibrated p 0.527 | 3.2 EB05 3.1 · IC025 +1.6 3/3 methods agree vs other NSAIDs: PRR 4.3 (4.2–4.4) | Not in label — unassessed | age-adj. PRR 3.1 · serious PRR 4.4 | NCT00346216: 1/7,933 (0.0%) on Naproxen (serious AE) |
| Product use issue | 6,186 | 5.0 4.9–5.1ROR 5.2 · calibrated p 0.214 | 4.9 EB05 4.8 · IC025 +2.2 3/3 methods agree vs other NSAIDs: PRR 7.7 (7.5–7.9) | Reporting / coding artifact | age-adj. PRR 5.1 · serious PRR 4.4 | not reported in cached trials |
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=396, PRR 369.6
- Immunisation — n=256, PRR 215.3
- Congenital hiatus hernia — n=123, PRR 185.4
- Grip strength — n=128, PRR 183.4
- Palmoplantar keratoderma — n=383, PRR 168.9
- Facet joint syndrome — n=1,649, PRR 163.1 (also seen in trial arm)
- Lupus vulgaris — n=613, PRR 157.8
- Swollen joint count — n=124, PRR 150.8
- Deep vein thrombosis postoperative — n=984, PRR 149.5 (also seen in trial arm)
- Subcutaneous drug absorption impaired — n=241, PRR 117.4
✓ A hand-written Bradford Hill causality assessment exists for this drug: Methotrexate Sodium ↔ Rheumatoid Arthritis.
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, nausea, arthralgia, 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, 1,190 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.