Drug · FAERS side-effect profile with label screen
Omeprazole Magnesium side effects: what 444,238 FDA adverse event reports show
Who reports
444,238 reports · 72% serious · 39,121 with death outcome · 60% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Omeprazole is a proton pump inhibitor (PPI) indicated for the: • Treatment of active duodenal ulcer in adults (1.1) • Eradication of Helicobacter pylori to reduce the risk of duodenal ulcer recurrence in adults (1.2) • Treatment of active benign gastri.
FDA label, Indications and Usage
What it is
6-methoxy-2-[(4-methoxy-3,5-dimethyl-2-pyridinyl)methylsulfinyl]-1H-benzimidazole is a sulfoxide and a member of benzimidazoles.
PubChem CID 4594 (ChEBI)
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 2Labeled (related wording) 4Likely indication confounding 2Reporting / coding artifact 1Lab value / disease marker 2Not in label — unassessed 29
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.
- 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). 1,108 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 |
|---|---|---|---|---|---|---|
| Renal haemangioma | 791 | 6,006.8 2,690.4–13,411.2ROR 6,017.5 · calibrated p 2e-21 ✓ | 46.2 EB05 43.5 · IC025 +5.4 3/3 methods agree vs other Proton Pump Inhibitors: PRR 5.4 (5.0–5.9) | Not in label — unassessed | serious n=791 · 100% consumer | not reported in cached trials |
| Rebound acid hypersecretion | 2,370 | 164.4 150.8–179.2ROR 165.2 · calibrated p 2e-9 ✓ | 36.4 EB05 35.2 · IC025 +5.1 3/3 methods agree vs other Proton Pump Inhibitors: PRR 6.2 (6.0–6.5) | Likely indication confounding shares a disease stem with the indications wording | serious n=2,364 · 100% consumer | not reported in cached trials |
| Cardiospasm | 394 | 114.3 95.0–137.6ROR 114.4 · calibrated p 5e-8 ✓ | 33.2 EB05 30.6 · IC025 +4.8 3/3 methods agree vs other Proton Pump Inhibitors: PRR 3.5 (3.1–3.9) | Not in label — unassessed | serious n=394 | not reported in cached trials |
| Chronic kidney disease-mineral and bone disorder | 753 | 111.0 97.3–126.8ROR 111.2 · calibrated p 6e-8 ✓ | 33.0 EB05 31.1 · IC025 +4.9 3/3 methods agree vs other Proton Pump Inhibitors: PRR 6.8 (6.3–7.4) | Not in label — unassessed | serious n=752 | not reported in cached trials |
| Nephrogenic anaemia | 2,967 | 82.1 77.3–87.2ROR 82.6 · calibrated p 5e-7 ✓ | 29.9 EB05 29.0 · IC025 +4.8 3/3 methods agree vs other Proton Pump Inhibitors: PRR 6.7 (6.4–7.0) | Not in label — unassessed | serious n=2,967 | not reported in cached trials |
| End stage renal disease | 10,574 | 63.4 61.5–65.2ROR 64.9 · calibrated p 2e-6 ✓ | 27.1 EB05 26.7 · IC025 +4.7 3/3 methods agree vs other Proton Pump Inhibitors: PRR 5.6 (5.5–5.7) | Not in label — unassessed | serious PRR 21.7 | not reported in cached trials |
| Palmoplantar keratoderma | 386 | 54.1 46.7–62.7ROR 54.2 · calibrated p 9e-6 ✓ | 25.3 EB05 23.2 · IC025 +4.4 3/3 methods agree vs other Proton Pump Inhibitors: PRR 3.5 (3.1–3.9) | Not in label — unassessed | serious n=386 | not reported in cached trials |
| Hyperparathyroidism secondary | 1,340 | 52.7 48.7–57.0ROR 52.8 · calibrated p 1e-5 ✓ | 25.0 EB05 23.9 · IC025 +4.5 3/3 methods agree vs other Proton Pump Inhibitors: PRR 6.9 (6.5–7.4) | Not in label — unassessed | serious n=1,340 | not reported in cached trials |
| Hypertensive nephropathy | 530 | 45.1 40.0–50.9ROR 45.2 · calibrated p 3e-5 ✓ | 23.2 EB05 21.5 · IC025 +4.4 3/3 methods agree vs other Proton Pump Inhibitors: PRR 4.8 (4.4–5.3) | Not in label — unassessed | serious n=530 · 100% consumer | not reported in cached trials |
| Chronic kidney disease | 36,748 | 43.0 42.5–43.7ROR 46.8 · calibrated p 2e-5 ✓ | 22.6 EB05 22.4 · IC025 +4.5 3/3 methods agree vs other Proton Pump Inhibitors: PRR 5.6 (5.6–5.6) | Not in label — unassessed | age-adj. PRR 16.4 · serious PRR 17.9 | not reported in cached trials |
| Hyperchlorhydria | 2,758 | 40.4 38.4–42.6ROR 40.7 · calibrated p 5e-5 ✓ | 21.9 EB05 21.2 · IC025 +4.4 3/3 methods agree vs other Proton Pump Inhibitors: PRR 8.6 (8.2–9.0) | Not in label — unassessed | serious n=1,904 · 100% consumer | not reported in cached trials |
| Renal injury | 9,730 | 22.3 21.8–22.8ROR 22.8 · calibrated p 0.001 ✓ | 15.3 EB05 15.0 · IC025 +3.9 3/3 methods agree vs other Proton Pump Inhibitors: PRR 5.6 (5.5–5.7) | Not in label — unassessed | serious PRR 12.3 | not reported in cached trials |
| Tubulointerstitial nephritis | 5,325 | 18.4 17.9–19.0ROR 18.6 · calibrated p 0.003 ✓ | 13.4 EB05 13.1 · IC025 +3.7 3/3 methods agree vs other Proton Pump Inhibitors: PRR 6.1 (5.9–6.2) | Labeled adverse reaction exact term | age-adj. PRR 7.9 · serious PRR 10.8 | NCT00141102: 1/2,237 (0.0%) on Omeprazole (serious AE) |
| Diabetic nephropathy | 554 | 15.5 14.1–17.0ROR 15.5 · calibrated p 0.006 ✓ | 11.8 EB05 11.0 · IC025 +3.4 3/3 methods agree vs other Proton Pump Inhibitors: PRR 5.0 (4.5–5.5) | Not in label — unassessed | serious n=551 · 100% consumer | not reported in cached trials |
| Sedation complication | 611 | 15.0 13.7–16.4ROR 15.0 · calibrated p 0.007 ✓ | 11.5 EB05 10.8 · IC025 +3.4 3/3 methods agree vs other Proton Pump Inhibitors: PRR 17.7 (15.8–19.8) | Reporting / coding artifact | serious n=608 · ♀ 100% (drug 60%) | not reported in cached trials |
| Atrial tachycardia | 480 | 13.7 12.3–15.1ROR 13.7 · calibrated p 0.010 ✓ | 10.7 EB05 9.9 · IC025 +3.3 3/3 methods agree vs other Proton Pump Inhibitors: PRR 3.9 (3.5–4.3) | Not in label — unassessed | serious n=478 | not reported in cached trials |
| Rebound effect | 2,394 | 12.4 11.9–13.0ROR 12.5 · calibrated p 0.015 ✓ | 10.0 EB05 9.6 · IC025 +3.2 3/3 methods agree vs other Proton Pump Inhibitors: PRR 9.6 (9.1–10.1) | Not in label — unassessed | serious PRR 8.7 · 100% consumer | not reported in cached trials |
| Hypomagnesaemia | 2,709 | 11.2 10.8–11.7ROR 11.3 · calibrated p 0.021 ✓ | 9.2 EB05 8.9 · IC025 +3.1 3/3 methods agree vs other Proton Pump Inhibitors: PRR 8.6 (8.2–8.9) | Not in label — unassessed | age-adj. PRR 10.0 · serious PRR 7.5 · 93% clinician | not reported in cached trials |
| Pruritus genital | 428 | 10.4 9.4–11.6ROR 10.4 · calibrated p 0.028 ✓ | 8.6 EB05 8.0 · IC025 +2.9 3/3 methods agree vs other Proton Pump Inhibitors: PRR 3.7 (3.3–4.1) | Labeled (related wording) related wording | serious n=414 | not reported in cached trials |
| Subacute cutaneous lupus erythematosus | 315 | 10.1 8.9–11.4ROR 10.1 · calibrated p 0.032 ✓ | 8.4 EB05 7.6 · IC025 +2.9 3/3 methods agree vs other Proton Pump Inhibitors: PRR 8.8 (7.7–10.1) | Labeled (related wording) related wording | serious n=313 · ♀ 100% (drug 60%) · 100% clinician | not reported in cached trials |
| Creatinine renal clearance decreased | 679 | 9.4 8.6–10.2ROR 9.4 · calibrated p 0.040 ✓ | 7.9 EB05 7.4 · IC025 +2.9 3/3 methods agree vs other Proton Pump Inhibitors: PRR 17.7 (15.9–19.7) | Lab value / disease marker | serious n=669 · ♀ 100% (drug 60%) | not reported in cached trials |
| Acute kidney injury (sudden kidney damage) | 23,910 | 8.6 8.5–8.7ROR 9.1 · calibrated p 0.045 ✓ | 7.4 EB05 7.3 · IC025 +2.9 3/3 methods agree vs other Proton Pump Inhibitors: PRR 5.9 (5.8–5.9) | Not in label — unassessed | age-adj. PRR 3.5 · serious PRR 5.9 | not reported in cached trials |
| Nephropathy | 1,411 | 8.2 7.7–8.7ROR 8.2 · calibrated p 0.062 | 7.1 EB05 6.8 · IC025 +2.7 3/3 methods agree vs other Proton Pump Inhibitors: PRR 5.1 (4.8–5.4) | Not in label — unassessed | serious PRR 6.0 | not reported in cached trials |
| Gastric polyps | 337 | 8.1 7.2–9.1ROR 8.1 · calibrated p 0.065 | 7.0 EB05 6.4 · IC025 +2.6 3/3 methods agree vs other Proton Pump Inhibitors: PRR 6.0 (5.3–6.8) | Labeled (related wording) related wording | serious n=292 · ♀ 100% (drug 60%) | not reported in cached trials |
| Carotid artery occlusion | 532 | 7.9 7.2–8.6ROR 7.9 · calibrated p 0.070 | 6.8 EB05 6.3 · IC025 +2.6 3/3 methods agree vs other Proton Pump Inhibitors: PRR 4.2 (3.8–4.6) | Not in label — unassessed | serious n=528 | not reported in cached trials |
| Essential hypertension | 371 | 7.7 6.9–8.6ROR 7.7 · calibrated p 0.074 | 6.7 EB05 6.2 · IC025 +2.6 3/3 methods agree vs other Proton Pump Inhibitors: PRR 8.0 (7.0–9.0) | Not in label — unassessed | serious n=348 | not reported in cached trials |
| Renal failure (kidney failure) | 18,173 | 7.3 7.2–7.4ROR 7.5 · calibrated p 0.079 | 6.4 EB05 6.3 · IC025 +2.7 3/3 methods agree vs other Proton Pump Inhibitors: PRR 6.2 (6.2–6.3) | Labeled (related wording) related wording | age-adj. PRR 3.3 · serious PRR 5.2 | NCT00141102: 1/2,237 (0.0%) on Omeprazole (serious AE) |
| Tension headache | 528 | 6.5 5.9–7.1ROR 6.5 · calibrated p 0.123 | 5.8 EB05 5.4 · IC025 +2.4 3/3 methods agree vs other Proton Pump Inhibitors: PRR 4.1 (3.7–4.5) | Not in label — unassessed | serious n=488 | not reported in cached trials |
| Hiatus hernia | 1,513 | 6.1 5.8–6.4ROR 6.1 · calibrated p 0.142 | 5.5 EB05 5.3 · IC025 +2.4 3/3 methods agree vs other Proton Pump Inhibitors: PRR 7.2 (6.8–7.7) | Not in label — unassessed | serious PRR 4.2 | not reported in cached trials |
| Gastrooesophageal reflux disease (acid reflux) | 9,309 | 6.1 5.9–6.2ROR 6.2 · calibrated p 0.139 | 5.5 EB05 5.4 · IC025 +2.4 3/3 methods agree vs other Proton Pump Inhibitors: PRR 5.8 (5.7–5.9) | Not in label — unassessed | age-adj. PRR 5.3 · serious PRR 5.0 | not reported in cached trials |
| Renal cyst | 866 | 5.6 5.3–6.1ROR 5.7 · calibrated p 0.175 | 5.1 EB05 4.8 · IC025 +2.2 3/3 methods agree vs other Proton Pump Inhibitors: PRR 6.2 (5.7–6.7) | Not in label — unassessed | serious PRR 4.3 | not reported in cached trials |
| Sleep terror | 419 | 5.1 4.6–5.7ROR 5.1 · calibrated p 0.223 | 4.7 EB05 4.3 · IC025 +2.1 3/3 methods agree vs other Proton Pump Inhibitors: PRR 3.6 (3.3–4.0) | Not in label — unassessed | serious n=407 | not reported in cached trials |
| Blood calcium decreased | 1,117 | 5.1 4.8–5.4ROR 5.1 · calibrated p 0.225 | 4.7 EB05 4.4 · IC025 +2.1 3/3 methods agree vs other Proton Pump Inhibitors: PRR 11.2 (10.4–12.1) | Lab value / disease marker | serious PRR 4.4 | not reported in cached trials |
| Hypocalcaemia (low calcium) | 1,852 | 5.0 4.8–5.3ROR 5.0 · calibrated p 0.230 | 4.6 EB05 4.4 · IC025 +2.1 3/3 methods agree vs other Proton Pump Inhibitors: PRR 8.0 (7.5–8.4) | Not in label — unassessed | age-adj. PRR 5.2 · serious PRR 3.9 · 93% clinician | not reported in cached trials |
| Infective pulmonary exacerbation of cystic fibrosis | 518 | 4.8 4.4–5.3ROR 4.8 · calibrated p 0.255 | 4.4 EB05 4.1 · IC025 +2.0 3/3 methods agree vs other Proton Pump Inhibitors: PRR 12.9 (11.5–14.4) | Not in label — unassessed | serious n=469 | not reported in cached trials |
| Regurgitation | 314 | 4.7 4.2–5.3ROR 4.7 · calibrated p 0.274 | 4.3 EB05 3.9 · IC025 +1.9 3/3 methods agree vs other Proton Pump Inhibitors: PRR 7.9 (6.9–9.0) | Labeled adverse reaction exact term | 100% consumer | not reported in cached trials |
| Spinal osteoarthritis | 785 | 4.5 4.2–4.9ROR 4.5 · calibrated p 0.295 | 4.2 EB05 3.9 · IC025 +1.9 3/3 methods agree vs other Proton Pump Inhibitors: PRR 8.2 (7.5–8.9) | Not in label — unassessed | serious PRR 3.5 | not reported in cached trials |
| Cholecystitis chronic | 592 | 4.4 4.1–4.8ROR 4.4 · calibrated p 0.308 | 4.1 EB05 3.8 · IC025 +1.9 3/3 methods agree vs other Proton Pump Inhibitors: PRR 9.7 (8.8–10.7) | Not in label — unassessed | serious PRR 3.3 · ♀ 100% (drug 60%) | NCT00141102: 1/2,223 (0.0%) on Omeprazole (serious AE) |
| Orthostatic hypotension (dizziness on standing) | 1,518 | 4.4 4.2–4.6ROR 4.4 · calibrated p 0.309 | 4.1 EB05 3.9 · IC025 +2.0 3/3 methods agree vs other Proton Pump Inhibitors: PRR 10.4 (9.8–11.1) | Not in label — unassessed | serious PRR 3.6 | not reported in cached trials |
| Oesophageal disorder | 333 | 4.4 3.9–4.9ROR 4.4 · calibrated p 0.317 | 4.1 EB05 3.7 · IC025 +1.8 3/3 methods agree vs other Proton Pump Inhibitors: PRR 11.1 (9.7–12.8) | Likely indication confounding term in indications; also in warnings | 100% consumer | 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 |
|---|---|---|---|
| Kidney injury | 44,855 | 5.05.0–5.1 | signal |
| Hyponatraemia | 5,315 | 3.33.2–3.4 | signal |
| Gi bleeding | 8,620 | 2.32.2–2.3 | signal |
| Anaemia | 12,371 | 2.02.0–2.0 | raised |
| Arrhythmia / qt | 7,807 | 1.91.9–2.0 | raised |
| Fall / fracture | 14,951 | 1.91.9–1.9 | raised |
| Pancreatitis | 3,074 | 1.81.8–1.9 | raised |
| Serious infection | 28,209 | 1.81.7–1.8 | raised |
| Depression | 10,020 | 1.71.7–1.7 | raised |
| Venous thromboembolism | 7,553 | 1.71.6–1.7 | raised |
| Rhabdomyolysis / myopathy | 2,791 | 1.61.6–1.7 | raised |
| Tendon disorder | 1,279 | 1.61.5–1.7 | raised |
| Heart failure | 5,833 | 1.61.5–1.6 | raised |
| Severe cutaneous reaction | 2,412 | 1.51.5–1.6 | raised |
| Thrombocytopenia | 7,133 | 1.51.5–1.6 | raised |
| Interstitial lung disease | 2,719 | 1.31.3–1.4 | raised |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Omeprazole 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 (3 of 40 signal terms matched).
- NCT00141102 — Study Of Celecoxib Or Diclofenac And Omeprazole For Gastrointestinal (GI) Safety In High GI Risk Patients With (N=4484, PHASE4; 146 AE terms posted; arms: Celecoxib; Oral Diclofenac Plus Omeprazole)
- NCT00444275 — Nexium (Esomeprazole) in Symptom Adapted Therapy in GERD Patients (N=3029, PHASE4; 49 AE terms posted; arms: Esomeprazole 20 mg Once Daily (Initial P; Esomeprazole 40 mg Once Daily (Initial P; Esomeprazole 20 mg Once Daily (Maintenan; Esomeprazole 20 mg on Demand (Maintenanc)
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 |
|---|---|---|---|---|---|---|
| Chronic kidney disease | 36,748 | 43.0 42.5–43.7ROR 46.8 · calibrated p 2e-5 ✓ | 22.6 EB05 22.4 · IC025 +4.5 3/3 methods agree vs other Proton Pump Inhibitors: PRR 5.6 (5.6–5.6) | Not in label — unassessed | age-adj. PRR 16.4 · serious PRR 17.9 | not reported in cached trials |
| Nausea | 26,836 | 1.6 1.6–1.6ROR 1.7 · calibrated p 0.749 | 1.6 EB05 1.6 · IC025 +0.7 vs other Proton Pump Inhibitors: PRR 8.1 (8.0–8.1) | Labeled adverse reaction exact term | age-adj. PRR 1.6 · serious PRR 1.6 | NCT00141102: 3/2,237 (0.1%) on Omeprazole (serious AE) |
| Fatigue (tiredness) | 26,028 | 1.6 1.6–1.6ROR 1.6 · calibrated p 0.731 | 1.6 EB05 1.6 · IC025 +0.6 vs other Proton Pump Inhibitors: PRR 8.8 (8.7–8.9) | Labeled adverse reaction exact term | age-adj. PRR 1.5 · serious PRR 1.6 | not reported in cached trials |
| Diarrhoea (diarrhea) | 25,414 | 1.9 1.9–1.9ROR 2.0 · calibrated p 0.919 | 1.9 EB05 1.8 · IC025 +0.9 vs other Proton Pump Inhibitors: PRR 8.2 (8.2–8.3) | Labeled adverse reaction exact term | age-adj. PRR 1.7 · serious PRR 1.7 | NCT00141102: 2/2,237 (0.1%) on Omeprazole (serious AE) |
| Acute kidney injury (sudden kidney damage) | 23,910 | 8.6 8.5–8.7ROR 9.1 · calibrated p 0.045 ✓ | 7.4 EB05 7.3 · IC025 +2.9 3/3 methods agree vs other Proton Pump Inhibitors: PRR 5.9 (5.8–5.9) | Not in label — unassessed | age-adj. PRR 3.5 · serious PRR 5.9 | not reported in cached trials |
| Drug ineffective (drug did not work) | 22,848 | 0.8 0.8–0.8ROR 0.8 · calibrated p 0.187 | 0.8 EB05 0.8 · IC025 -0.3 PRR-only: not supported by EBGM or IC vs other Proton Pump Inhibitors: PRR 7.8 (7.7–7.8) | Reporting / coding artifact | age-adj. PRR 1.0 · serious PRR 0.9 | not reported in cached trials |
| Dyspnoea (shortness of breath) | 20,993 | 1.8 1.8–1.8ROR 1.8 · calibrated p 0.841 | 1.8 EB05 1.7 · IC025 +0.8 vs other Proton Pump Inhibitors: PRR 8.0 (7.9–8.0) | Not in label — unassessed | age-adj. PRR 1.6 · serious PRR 1.6 | NCT00141102: 1/2,237 (0.0%) on Omeprazole (serious AE) |
| Pain | 20,317 | 1.6 1.6–1.6ROR 1.6 · calibrated p 0.710 | 1.6 EB05 1.5 · IC025 +0.6 vs other Proton Pump Inhibitors: PRR 8.3 (8.2–8.4) | Labeled adverse reaction exact term | age-adj. PRR 1.7 · serious PRR 1.4 | NCT00141102: 1/2,237 (0.0%) on Omeprazole (serious AE) |
| Headache | 19,306 | 1.5 1.4–1.5ROR 1.5 · calibrated p 0.636 | 1.5 EB05 1.4 · IC025 +0.5 vs other Proton Pump Inhibitors: PRR 7.6 (7.5–7.7) | Labeled adverse reaction exact term | age-adj. PRR 1.5 · serious PRR 1.5 | NCT00141102: 1/2,237 (0.0%) on Omeprazole (serious AE) |
| Renal failure (kidney failure) | 18,173 | 7.3 7.2–7.4ROR 7.5 · calibrated p 0.079 | 6.4 EB05 6.3 · IC025 +2.7 3/3 methods agree vs other Proton Pump Inhibitors: PRR 6.2 (6.2–6.3) | Labeled (related wording) related wording | age-adj. PRR 3.3 · serious PRR 5.2 | NCT00141102: 1/2,237 (0.0%) on Omeprazole (serious AE) |
| Vomiting | 17,282 | 1.8 1.7–1.8ROR 1.8 · calibrated p 0.829 | 1.7 EB05 1.7 · IC025 +0.8 vs other Proton Pump Inhibitors: PRR 7.7 (7.6–7.8) | Labeled adverse reaction exact term | age-adj. PRR 1.8 · serious PRR 1.6 | NCT00141102: 2/2,237 (0.1%) on Omeprazole (serious AE) |
| Dizziness | 17,104 | 1.6 1.6–1.7ROR 1.7 · calibrated p 0.750 | 1.6 EB05 1.6 · IC025 +0.7 vs other Proton Pump Inhibitors: PRR 8.6 (8.5–8.7) | Labeled adverse reaction exact term | age-adj. PRR 1.5 · serious PRR 1.6 | NCT00141102: 2/2,237 (0.1%) on Omeprazole (serious AE) |
| Off label use (used outside approved label) | 16,271 | 0.9 0.9–0.9ROR 0.9 · calibrated p 0.229 | 0.9 EB05 0.9 · IC025 -0.2 PRR-only: not supported by EBGM or IC vs other Proton Pump Inhibitors: PRR 6.8 (6.7–6.9) | Reporting / coding artifact | age-adj. PRR 0.9 · serious PRR 0.9 | not reported in cached trials |
| Malaise (feeling unwell) | 14,021 | 1.5 1.5–1.5ROR 1.5 · calibrated p 0.667 | 1.5 EB05 1.5 · IC025 +0.6 vs other Proton Pump Inhibitors: PRR 6.8 (6.7–6.9) | Labeled adverse reaction exact term | age-adj. PRR 1.5 · serious PRR 1.5 | not reported in cached trials |
| Asthenia (weakness) | 13,952 | 1.8 1.8–1.8ROR 1.8 · calibrated p 0.833 | 1.8 EB05 1.7 · IC025 +0.8 vs other Proton Pump Inhibitors: PRR 8.4 (8.3–8.6) | Labeled adverse reaction exact term | age-adj. PRR 1.5 · serious PRR 1.6 | NCT00444275: 2/873 (0.2%) on Omeprazole |
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.
- Renal haemangioma — n=791, PRR 6,006.8
- Cardiospasm — n=394, PRR 114.3
- Chronic kidney disease-mineral and bone disorder — n=753, PRR 111.0
- Nephrogenic anaemia — n=2,967, PRR 82.1
- End stage renal disease — n=10,574, PRR 63.4
- Palmoplantar keratoderma — n=386, PRR 54.1
- Hyperparathyroidism secondary — n=1,340, PRR 52.7
- Hypertensive nephropathy — n=530, PRR 45.1
- Chronic kidney disease — n=36,748, PRR 43.0
- Hyperchlorhydria — n=2,758, PRR 40.4
✓ A hand-written Bradford Hill causality assessment exists for this drug: Omeprazole (proton-pump inhibitors) ↔ Chronic kidney disease.
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 Omeprazole?
In FDA FAERS, the most frequently co-reported reaction terms for Omeprazole are chronic kidney disease, nausea, fatigue, diarrhoea, 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 Omeprazole have an FDA boxed warning?
No. The FDA label retrieved for Omeprazole has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Omeprazole 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 062800b1-790a-41c3-a8be-94143d2c7fb6, effective 20260801; matched on
openfda.generic_name.exact:"OMEPRAZOLE" AND openfda.product_type:"HUMAN PRESCRIPTION DRUG") - PubChem CID 4594 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, 1,148 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
OMEPRAZOLE, 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.