Drug · FAERS side-effect profile with label screen
Cimetidine side effects: what 9,571 FDA adverse event reports show
Drug class
Histamine-2 Receptor Antagonist
FDA label (Established Pharmacologic Class) · compare the class
Who reports
9,571 reports · 81% serious · 1,196 with death outcome · 66% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Cimetidine tablets are indicated in: 1. Short-term treatment of active duodenal ulcer. Most patients heal within 4 weeks and there is rarely reason to use cimetidine tablets at full dosage for longer than 6 to 8 weeks (see DOSAGE AND ADMINISTRATION: Duodenal Ulcer ). Concomitant antacids should be given as needed for relief of pain.
FDA label, Indications and Usage
What it is
DESCRIPTION Cimetidine, USP is a histamine H 2 -receptor antagonist.
FDA label, Description section
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
Likely indication confounding 2Reporting / coding artifact 1Lab value / disease marker 15Not in label — unassessed 22
What the badges mean
- 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 flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 1,103 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 |
|---|---|---|---|---|---|---|
| Specific gravity urine decreased | 20 | 329.8 206.1–527.8ROR 330.5 · χ² 5,406 / p <1e-300 | 224.9 EB05 153.8 · IC025 +4.4 3/3 methods agree | Lab value / disease marker | serious n=20 | no trial data cached |
| Body tinea | 56 | 241.5 183.3–318.0ROR 242.9 · χ² 11,847 / p <1e-300 | 202.4 EB05 161.7 · IC025 +5.8 3/3 methods agree | Not in label — unassessed | serious n=56 · ♀ 100% (drug 66%) · 93% clinician | no trial data cached |
| Urine leukocyte esterase positive | 53 | 177.2 134.0–234.4ROR 178.2 · χ² 8,422 / p <1e-300 | 154.8 EB05 122.9 · IC025 +5.6 3/3 methods agree | Lab value / disease marker | serious n=51 · ♀ 100% (drug 66%) | no trial data cached |
| Urobilinogen urine increased | 12 | 174.0 96.7–313.2ROR 174.2 · χ² 1,753 / p <1e-300 | 128.7 EB05 78.4 · IC025 +3.5 3/3 methods agree | Lab value / disease marker | serious n=12 | no trial data cached |
| Creatinine urine decreased | 10 | 151.1 79.6–286.7ROR 151.2 · χ² 1,257 / p 2e-275 | 111.8 EB05 64.9 · IC025 +3.1 3/3 methods agree | Lab value / disease marker | serious n=9 | no trial data cached |
| Red cell distribution width decreased | 19 | 93.7 59.2–148.3ROR 93.9 · χ² 1,583 / p <1e-300 | 82.6 EB05 55.9 · IC025 +4.0 3/3 methods agree | Lab value / disease marker | serious n=19 | no trial data cached |
| Chronic kidney disease-mineral and bone disorder | 42 | 89.0 65.4–121.0ROR 89.3 · χ² 3,424 / p <1e-300 | 82.4 EB05 63.5 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=42 | no trial data cached |
| Nitrite urine present | 16 | 82.7 50.2–136.2ROR 82.8 · χ² 1,166 / p 7e-256 | 73.0 EB05 47.6 · IC025 +3.7 3/3 methods agree | Lab value / disease marker | serious n=16 | no trial data cached |
| Culture urine positive | 50 | 80.3 60.6–106.4ROR 80.7 · χ² 3,700 / p <1e-300 | 75.3 EB05 59.4 · IC025 +5.0 3/3 methods agree | Lab value / disease marker | serious n=49 · ♀ 92% (drug 66%) | no trial data cached |
| Inhibitory drug interaction | 56 | 79.9 61.2–104.3ROR 80.4 · χ² 4,132 / p <1e-300 | 75.2 EB05 60.1 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious n=56 · ♀ 100% (drug 66%) · 100% clinician | no trial data cached |
| Anion gap decreased | 12 | 79.3 44.6–141.0ROR 79.4 · χ² 821 / p 8e-181 | 68.5 EB05 41.8 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Rebound acid hypersecretion | 106 | 78.4 64.7–95.1ROR 79.3 · χ² 7,742 / p <1e-300 | 74.7 EB05 63.5 · IC025 +5.5 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=106 | no trial data cached |
| Androgen deficiency | 12 | 76.9 43.3–136.8ROR 77.0 · χ² 797 / p 2e-175 | 66.8 EB05 40.7 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Urine ketone body present | 43 | 61.2 45.3–82.9ROR 61.5 · χ² 2,420 / p <1e-300 | 58.1 EB05 44.9 · IC025 +4.6 3/3 methods agree | Lab value / disease marker | serious n=43 · ♀ 88% (drug 66%) | no trial data cached |
| Nephrogenic anaemia | 127 | 61.1 51.3–72.9ROR 62.0 · χ² 7,250 / p <1e-300 | 59.0 EB05 50.9 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious n=127 | no trial data cached |
| Calcium deficiency | 35 | 60.4 43.2–84.5ROR 60.7 · χ² 1,933 / p <1e-300 | 57.1 EB05 42.9 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=34 | no trial data cached |
| Infection susceptibility increased | 57 | 58.6 45.1–76.2ROR 59.0 · χ² 3,088 / p <1e-300 | 56.1 EB05 44.9 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious n=57 · ♀ 100% (drug 66%) · 91% clinician | no trial data cached |
| Hyperparathyroidism secondary | 66 | 58.6 45.9–74.8ROR 59.0 · χ² 3,583 / p <1e-300 | 56.2 EB05 45.7 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=66 | no trial data cached |
| Urine abnormality | 91 | 45.3 36.9–55.7ROR 45.8 · χ² 3,822 / p <1e-300 | 44.0 EB05 37.0 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious n=89 · ♀ 92% (drug 66%) | no trial data cached |
| End stage renal disease | 348 | 42.2 38.0–46.8ROR 43.7 · χ² 13,690 / p <1e-300 | 41.3 EB05 37.8 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious PRR 29.5 | no trial data cached |
| Chronic kidney disease | 1,266 | 36.8 34.9–38.7ROR 42.2 · χ² 43,442 / p <1e-300 | 36.2 EB05 34.5 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious PRR 26.2 | no trial data cached |
| Band sensation | 20 | 34.8 22.4–54.1ROR 34.9 · χ² 614 / p 9e-136 | 33.3 EB05 22.8 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=19 | no trial data cached |
| White blood cells urine positive | 29 | 34.5 23.9–49.8ROR 34.6 · χ² 896 / p 3e-197 | 33.3 EB05 24.3 · IC025 +3.8 3/3 methods agree | Lab value / disease marker | serious n=27 · ♀ 100% (drug 66%) | no trial data cached |
| Red blood cells urine positive | 15 | 34.4 20.7–57.3ROR 34.5 · χ² 447 / p 2e-99 | 32.6 EB05 21.0 · IC025 +3.2 3/3 methods agree | Lab value / disease marker | serious n=14 | no trial data cached |
| Monocyte count decreased | 17 | 31.1 19.3–50.3ROR 31.2 · χ² 460 / p 3e-102 | 29.8 EB05 19.7 · IC025 +3.2 3/3 methods agree | Lab value / disease marker | serious n=16 | no trial data cached |
| Aortic valve sclerosis | 10 | 30.2 16.2–56.4ROR 30.2 · χ² 251 / p 1e-56 | 28.3 EB05 16.3 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Basophil count increased | 10 | 29.5 15.8–55.0ROR 29.5 · χ² 244 / p 3e-55 | 27.6 EB05 15.8 · IC025 +2.6 3/3 methods agree | Lab value / disease marker | serious n=9 | no trial data cached |
| Primary sequestrum | 12 | 29.0 16.4–51.2ROR 29.0 · χ² 293 / p 5e-66 | 27.5 EB05 16.6 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Bacterial test positive | 27 | 26.8 18.4–39.2ROR 26.9 · χ² 638 / p 4e-141 | 26.1 EB05 18.8 · IC025 +3.5 3/3 methods agree | Lab value / disease marker | serious n=27 · ♀ 100% (drug 66%) | no trial data cached |
| Leukocyturia | 10 | 26.8 14.4–50.1ROR 26.9 · χ² 221 / p 3e-50 | 25.2 EB05 14.3 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Mean cell haemoglobin increased | 20 | 26.7 17.2–41.5ROR 26.8 · χ² 464 / p 4e-103 | 25.8 EB05 17.6 · IC025 +3.3 3/3 methods agree | Lab value / disease marker | serious n=20 | no trial data cached |
| Acute prerenal failure | 14 | 26.5 15.6–44.8ROR 26.5 · χ² 314 / p 1e-70 | 25.3 EB05 15.9 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious n=14 | no trial data cached |
| Drug exposure before pregnancy | 12 | 26.1 14.8–46.1ROR 26.1 · χ² 262 / p 3e-59 | 24.8 EB05 14.9 · IC025 +2.7 3/3 methods agree | Reporting / coding artifact | serious n=12 | no trial data cached |
| Tetany | 21 | 25.3 16.5–38.9ROR 25.4 · χ² 461 / p 1e-102 | 24.5 EB05 16.9 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=21 | no trial data cached |
| Mucosal erosion | 10 | 24.4 13.1–45.5ROR 24.4 · χ² 199 / p 1e-45 | 22.9 EB05 12.9 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Adenocarcinoma gastric | 10 | 24.0 12.9–44.8ROR 24.1 · χ² 196 / p 7e-45 | 22.6 EB05 12.6 · IC025 +2.4 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=10 | no trial data cached |
| Infusion site discomfort | 11 | 23.8 13.1–43.1ROR 23.8 · χ² 216 / p 4e-49 | 22.5 EB05 13.1 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious n=11 | no trial data cached |
| Glucose tolerance impaired | 62 | 23.3 18.2–30.0ROR 23.5 · χ² 1,290 / p 7e-283 | 23.0 EB05 18.6 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=61 · ♀ 100% (drug 66%) | no trial data cached |
| Secondary adrenocortical insufficiency | 15 | 22.2 13.3–36.8ROR 22.2 · χ² 279 / p 5e-63 | 21.3 EB05 13.5 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=15 | no trial data cached |
| Haematocrit increased | 22 | 21.3 14.0–32.4ROR 21.3 · χ² 402 / p 1e-89 | 20.7 EB05 14.3 · IC025 +3.2 3/3 methods agree | Lab value / disease marker | serious n=19 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).
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 | 1,266 | 36.8 34.9–38.7ROR 42.2 · χ² 43,442 / p <1e-300 | 36.2 EB05 34.5 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious PRR 26.2 | no trial data cached |
| Acute kidney injury (sudden kidney damage) | 717 | 10.4 9.6–11.1ROR 11.1 · χ² 6,066 / p <1e-300 | 10.3 EB05 9.7 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 7.4 | no trial data cached |
| Nausea | 709 | 2.0 1.8–2.1ROR 2.0 · χ² 350 / p 2e-78 | 2.0 EB05 1.8 · IC025 +0.9 | Not in label — unassessed | serious PRR 2.1 | no trial data cached |
| Renal failure (kidney failure) | 698 | 11.5 10.7–12.3ROR 12.3 · χ² 6,677 / p <1e-300 | 11.4 EB05 10.7 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 8.2 | no trial data cached |
| Fatigue (tiredness) | 631 | 1.8 1.7–1.9ROR 1.8 · χ² 223 / p 1e-50 | 1.8 EB05 1.7 · IC025 +0.7 | Not in label — unassessed | serious PRR 2.0 | no trial data cached |
| Drug ineffective (drug did not work) | 524 | 0.9 0.8–0.9ROR 0.9 · χ² 10 / p 6e-4 | 0.9 EB05 0.8 · IC025 -0.3 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 1.0 | no trial data cached |
| Dyspnoea (shortness of breath) | 518 | 2.0 1.8–2.2ROR 2.1 · χ² 268 / p 2e-60 | 2.0 EB05 1.9 · IC025 +0.9 | Not in label — unassessed | serious PRR 1.8 | no trial data cached |
| Vomiting | 507 | 2.4 2.2–2.6ROR 2.4 · χ² 409 / p 3e-91 | 2.4 EB05 2.2 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 2.2 | no trial data cached |
| Diarrhoea (diarrhea) | 468 | 1.6 1.5–1.7ROR 1.6 · χ² 106 / p 3e-25 | 1.6 EB05 1.5 · IC025 +0.5 | Labeled adverse reaction exact term | serious PRR 1.6 | no trial data cached |
| Pain | 456 | 1.6 1.5–1.8ROR 1.7 · χ² 112 / p 2e-26 | 1.6 EB05 1.5 · IC025 +0.5 | Likely indication confounding term in indications | serious PRR 1.5 | no trial data cached |
| Death | 413 | 1.1 1.0–1.2ROR 1.1 · χ² 1 / p 0.160 | 1.1 EB05 1.0 · IC025 -0.1 PRR-only: not supported by EBGM or IC | Outcome field, not a reaction | serious PRR 0.8 | no trial data cached |
| Dizziness | 400 | 1.8 1.6–1.9ROR 1.8 · χ² 134 / p 3e-31 | 1.8 EB05 1.6 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 1.8 | no trial data cached |
| Headache | 391 | 1.4 1.2–1.5ROR 1.4 · χ² 39 / p 2e-10 | 1.4 EB05 1.3 · IC025 +0.3 | Labeled adverse reaction exact term | serious PRR 1.5 | no trial data cached |
| Off label use (used outside approved label) | 388 | 1.0 0.9–1.1ROR 1.0 · χ² 0 / p 0.346 | 1.0 EB05 0.9 · IC025 -0.2 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 1.1 | no trial data cached |
| Gastrooesophageal reflux disease (acid reflux) | 375 | 10.3 9.3–11.4ROR 10.7 · χ² 3,132 / p <1e-300 | 10.2 EB05 9.4 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 10.5 | 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.
- Body tinea — n=56, PRR 241.5
- Chronic kidney disease-mineral and bone disorder — n=42, PRR 89.0
- Inhibitory drug interaction — n=56, PRR 79.9
- Nephrogenic anaemia — n=127, PRR 61.1
- Calcium deficiency — n=35, PRR 60.4
- Infection susceptibility increased — n=57, PRR 58.6
- Hyperparathyroidism secondary — n=66, PRR 58.6
- Urine abnormality — n=91, PRR 45.3
- End stage renal disease — n=348, PRR 42.2
- Chronic kidney disease — n=1,266, PRR 36.8
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 Cimetidine?
In FDA FAERS, the most frequently co-reported reaction terms for Cimetidine are chronic kidney disease, acute kidney injury, nausea, renal failure, fatigue, 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 Cimetidine have an FDA boxed warning?
No. The FDA label retrieved for Cimetidine has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Cimetidine 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 01997826-7ca1-473e-bfc9-075b14b58a35, effective 20230818; matched on
openfda.generic_name.exact:"CIMETIDINE") - 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, 1,143 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.