Drug · FAERS side-effect profile with label screen
Acetaminophen and Diphenhydramine side effects: what 3,316 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Acetaminophen (Acetaminophen)
closest FDA label found for this product string; brand list suppressed because the label is a related product, not an exact match
Who reports
3,316 reports · 94% serious · 529 with death outcome · 64% female
openFDA FAERS counts, all years, deduplication not applied
Used for
temporarily relieves minor aches and pains due to: headache muscular aches backache minor pain of arthritis the common cold toothache premenstrual and menstrual cramps temporarily reduces fever
FDA label, Indications and Usage
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
Reporting / coding artifact 2Lab value / disease marker 3Not in label — unassessed 35
What the badges mean
- 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. 381 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 |
|---|---|---|---|---|---|---|
| Helicobacter infection | 123 | 77.2 64.8–91.9ROR 80.1 · χ² 9,066 / p <1e-300 | 75.4 EB05 64.9 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious PRR 49.2 · ♀ 100% (drug 64%) · 98% clinician | no trial data cached |
| Folliculitis | 124 | 76.8 64.5–91.4ROR 79.7 · χ² 9,094 / p <1e-300 | 75.0 EB05 64.6 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious PRR 54.4 · ♀ 98% (drug 64%) · 96% clinician | no trial data cached |
| Pemphigus | 123 | 63.2 53.1–75.2ROR 65.6 · χ² 7,392 / p <1e-300 | 62.0 EB05 53.3 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious PRR 38.3 · ♀ 100% (drug 64%) · 98% clinician | no trial data cached |
| Hand deformity | 125 | 61.0 51.3–72.5ROR 63.3 · χ² 7,247 / p <1e-300 | 59.9 EB05 51.6 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious PRR 40.1 · ♀ 100% (drug 64%) · 98% clinician | no trial data cached |
| Pericarditis | 137 | 52.4 44.4–61.8ROR 54.6 · χ² 6,803 / p <1e-300 | 51.6 EB05 44.8 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious PRR 31.9 · ♀ 94% (drug 64%) · 96% clinician | no trial data cached |
| Hypercholesterolaemia | 71 | 47.3 37.5–59.5ROR 48.3 · χ² 3,146 / p <1e-300 | 46.4 EB05 38.0 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious PRR 30.4 · ♀ 100% (drug 64%) · 97% clinician | no trial data cached |
| Synovitis | 128 | 45.1 38.1–53.5ROR 46.9 · χ² 5,447 / p <1e-300 | 44.6 EB05 38.4 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious PRR 28.6 · ♀ 100% (drug 64%) · 98% clinician | no trial data cached |
| Joint range of motion decreased | 87 | 41.4 33.6–51.0ROR 42.5 · χ² 3,370 / p <1e-300 | 40.8 EB05 34.1 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious PRR 32.0 · ♀ 100% (drug 64%) · 92% clinician | no trial data cached |
| Bursitis | 72 | 37.9 30.2–47.7ROR 38.8 · χ² 2,539 / p <1e-300 | 37.4 EB05 30.7 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious PRR 26.7 · ♀ 97% (drug 64%) | no trial data cached |
| Glossodynia (burning tongue/mouth pain) | 125 | 35.5 29.9–42.2ROR 36.9 · χ² 4,142 / p <1e-300 | 35.2 EB05 30.3 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious PRR 31.0 · ♀ 100% (drug 64%) · 97% clinician | no trial data cached |
| Wound infection | 60 | 35.1 27.3–45.1ROR 35.7 · χ² 1,943 / p <1e-300 | 34.5 EB05 27.8 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious PRR 22.8 · ♀ 93% (drug 64%) · 95% clinician | no trial data cached |
| Irritable bowel syndrome | 112 | 33.3 27.7–40.0ROR 34.4 · χ² 3,462 / p <1e-300 | 33.0 EB05 28.2 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious PRR 25.7 · ♀ 100% (drug 64%) · 97% clinician | no trial data cached |
| Autoimmune disorder | 47 | 31.2 23.5–41.5ROR 31.6 · χ² 1,337 / p 5e-293 | 30.7 EB05 24.0 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious PRR 20.2 · ♀ 100% (drug 64%) · 98% clinician | no trial data cached |
| Wound | 135 | 30.8 26.1–36.4ROR 32.1 · χ² 3,854 / p <1e-300 | 30.6 EB05 26.5 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious PRR 22.3 · ♀ 100% (drug 64%) · 97% clinician | no trial data cached |
| Systemic lupus erythematosus | 164 | 29.4 25.3–34.2ROR 30.9 · χ² 4,464 / p <1e-300 | 29.2 EB05 25.7 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious PRR 18.3 · ♀ 90% (drug 64%) · 96% clinician | no trial data cached |
| Fibromyalgia | 102 | 26.7 22.0–32.3ROR 27.5 · χ² 2,485 / p <1e-300 | 26.4 EB05 22.4 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious PRR 21.3 · ♀ 100% (drug 64%) · 98% clinician | no trial data cached |
| Impaired healing | 134 | 25.9 21.9–30.6ROR 26.9 · χ² 3,174 / p <1e-300 | 25.7 EB05 22.3 · IC025 +4.3 3/3 methods agree | Reporting / coding artifact | serious PRR 19.0 · ♀ 100% (drug 64%) · 95% clinician | no trial data cached |
| Liver injury | 97 | 25.5 20.9–31.0ROR 26.2 · χ² 2,248 / p <1e-300 | 25.2 EB05 21.3 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious PRR 16.0 · ♀ 98% (drug 64%) · 93% clinician | no trial data cached |
| Obesity | 62 | 24.7 19.3–31.6ROR 25.1 · χ² 1,379 / p <1e-300 | 24.4 EB05 19.7 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious PRR 17.4 · ♀ 95% (drug 64%) · 92% clinician | no trial data cached |
| Sciatica | 58 | 23.2 18.0–30.0ROR 23.6 · χ² 1,206 / p 1e-264 | 23.0 EB05 18.4 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious PRR 18.6 · ♀ 100% (drug 64%) · 91% clinician | no trial data cached |
| Red blood cell sedimentation rate increased | 39 | 22.3 16.3–30.5ROR 22.6 · χ² 770 / p 9e-170 | 22.0 EB05 16.8 · IC025 +3.6 3/3 methods agree | Lab value / disease marker | serious PRR 15.4 · ♀ 92% (drug 64%) | no trial data cached |
| Affect lability | 34 | 22.3 16.0–31.2ROR 22.5 · χ² 669 / p 1e-147 | 22.0 EB05 16.4 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 18.9 · ♀ 100% (drug 64%) · 100% clinician | no trial data cached |
| Type 2 diabetes mellitus | 115 | 21.6 18.0–25.9ROR 22.3 · χ² 2,234 / p <1e-300 | 21.5 EB05 18.4 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious PRR 13.8 · ♀ 98% (drug 64%) · 97% clinician | no trial data cached |
| Lower respiratory tract infection | 149 | 20.9 17.8–24.4ROR 21.8 · χ² 2,793 / p <1e-300 | 20.7 EB05 18.1 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious PRR 13.3 · ♀ 91% (drug 64%) | no trial data cached |
| Liver function test increased | 69 | 20.5 16.2–25.9ROR 20.9 · χ² 1,259 / p 6e-276 | 20.3 EB05 16.6 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious PRR 19.5 · ♀ 94% (drug 64%) | no trial data cached |
| Lower limb fracture | 57 | 18.9 14.6–24.5ROR 19.2 · χ² 948 / p 2e-208 | 18.8 EB05 15.0 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 12.6 · ♀ 95% (drug 64%) | no trial data cached |
| Psoriatic arthropathy | 117 | 18.4 15.4–22.0ROR 19.1 · χ² 1,911 / p <1e-300 | 18.3 EB05 15.7 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious PRR 14.1 · ♀ 100% (drug 64%) · 96% clinician | no trial data cached |
| Coeliac disease | 27 | 17.4 12.0–25.4ROR 17.6 · χ² 401 / p 2e-89 | 17.1 EB05 12.2 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 13.2 · ♀ 96% (drug 64%) · 93% clinician | no trial data cached |
| Delirium | 93 | 17.0 13.9–20.8ROR 17.5 · χ² 1,387 / p <1e-300 | 16.9 EB05 14.2 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 10.6 · ♀ 93% (drug 64%) | no trial data cached |
| Prescribed overdose | 51 | 16.7 12.7–21.9ROR 16.9 · χ² 736 / p 2e-162 | 16.5 EB05 13.0 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious PRR 17.0 · ♀ 100% (drug 64%) · 92% clinician | no trial data cached |
| Gait inability | 85 | 16.3 13.2–20.1ROR 16.7 · χ² 1,202 / p 1e-263 | 16.2 EB05 13.5 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious PRR 12.3 · ♀ 93% (drug 64%) | no trial data cached |
| Pulmonary fibrosis | 49 | 16.2 12.3–21.5ROR 16.5 · χ² 685 / p 3e-151 | 16.1 EB05 12.6 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 10.0 · ♀ 100% (drug 64%) | no trial data cached |
| Apathy | 37 | 16.1 11.7–22.2ROR 16.3 · χ² 509 / p 4e-113 | 15.9 EB05 11.9 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 14.2 · ♀ 97% (drug 64%) · 95% clinician | no trial data cached |
| C-reactive protein increased | 89 | 15.5 12.6–19.0ROR 15.9 · χ² 1,192 / p 1e-261 | 15.4 EB05 12.9 · IC025 +3.5 3/3 methods agree | Lab value / disease marker | serious PRR 9.8 | no trial data cached |
| Infusion related reaction (reaction during infusion) | 158 | 15.2 13.0–17.6ROR 15.9 · χ² 2,076 / p <1e-300 | 15.1 EB05 13.2 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious PRR 11.6 · ♀ 96% (drug 64%) · 96% clinician | no trial data cached |
| Joint dislocation | 25 | 15.0 10.2–22.2ROR 15.1 · χ² 313 / p 2e-70 | 14.6 EB05 10.1 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 10.3 · ♀ 92% (drug 64%) | no trial data cached |
| Back injury | 25 | 14.6 9.9–21.6ROR 14.7 · χ² 303 / p 3e-68 | 14.2 EB05 9.8 · IC025 +2.9 3/3 methods agree | Not in label — unassessed | serious PRR 11.8 · ♀ 96% (drug 64%) · 96% clinician | no trial data cached |
| Blood cholesterol increased | 105 | 14.3 11.8–17.2ROR 14.7 · χ² 1,282 / p 6e-281 | 14.2 EB05 12.0 · IC025 +3.4 3/3 methods agree | Lab value / disease marker | serious PRR 13.2 · ♀ 93% (drug 64%) · 90% clinician | no trial data cached |
| Contraindicated product administered | 67 | 14.1 11.1–17.8ROR 14.3 · χ² 800 / p 3e-176 | 13.9 EB05 11.3 · IC025 +3.3 3/3 methods agree | Reporting / coding artifact | serious PRR 10.7 · ♀ 100% (drug 64%) · 99% clinician | no trial data cached |
| Osteoarthritis | 92 | 13.7 11.2–16.8ROR 14.1 · χ² 1,072 / p 2e-235 | 13.6 EB05 11.4 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 9.4 · ♀ 94% (drug 64%) | 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 |
|---|---|---|---|---|---|---|
| Pyrexia (fever) | 318 | 5.8 5.2–6.5ROR 6.3 · χ² 1,282 / p 5e-281 | 5.8 EB05 5.2 · IC025 +2.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.3 | no trial data cached |
| Pain | 316 | 3.2 2.9–3.6ROR 3.5 · χ² 504 / p 7e-112 | 3.2 EB05 2.9 · IC025 +1.5 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 3.0 | no trial data cached |
| Headache | 309 | 3.1 2.8–3.5ROR 3.3 · χ² 457 / p 1e-101 | 3.1 EB05 2.8 · IC025 +1.4 3/3 methods agree | Likely indication confounding term in indications | serious PRR 3.7 | no trial data cached |
| Dyspnoea (shortness of breath) | 287 | 3.2 2.9–3.6ROR 3.4 · χ² 446 / p 3e-99 | 3.2 EB05 2.9 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 2.7 | no trial data cached |
| Confusional state (confusion) | 251 | 9.8 8.7–11.1ROR 10.5 · χ² 1,990 / p <1e-300 | 9.7 EB05 8.7 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 7.6 | no trial data cached |
| Rash | 235 | 3.4 3.0–3.9ROR 3.6 · χ² 410 / p 2e-91 | 3.4 EB05 3.1 · IC025 +1.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.5 | no trial data cached |
| Malaise (feeling unwell) | 232 | 3.3 2.9–3.8ROR 3.5 · χ² 385 / p 4e-86 | 3.3 EB05 3.0 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 3.3 | no trial data cached |
| Hypertension (high blood pressure) | 227 | 6.8 6.0–7.7ROR 7.2 · χ² 1,122 / p 3e-246 | 6.7 EB05 6.0 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 5.1 · ♀ 90% (drug 64%) | no trial data cached |
| Arthralgia (joint pain) | 224 | 3.4 3.0–3.9ROR 3.6 · χ² 388 / p 9e-87 | 3.4 EB05 3.0 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 · ♀ 85% (drug 64%) | no trial data cached |
| Pain in extremity | 203 | 4.4 3.8–5.0ROR 4.6 · χ² 527 / p 5e-117 | 4.3 EB05 3.8 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 4.6 | no trial data cached |
| General physical health deterioration | 197 | 10.9 9.5–12.4ROR 11.5 · χ² 1,760 / p <1e-300 | 10.8 EB05 9.5 · IC025 +3.2 3/3 methods agree | Reporting / coding artifact | serious PRR 7.7 · ♀ 89% (drug 64%) · 90% clinician | no trial data cached |
| Condition aggravated | 187 | 3.9 3.4–4.5ROR 4.1 · χ² 409 / p 3e-91 | 3.9 EB05 3.4 · IC025 +1.7 3/3 methods agree | Reporting / coding artifact | serious PRR 3.6 | no trial data cached |
| Fall | 186 | 3.5 3.1–4.1ROR 3.7 · χ² 341 / p 2e-76 | 3.5 EB05 3.1 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 2.5 | no trial data cached |
| Hypersensitivity (allergic reaction) | 176 | 6.0 5.2–6.9ROR 6.3 · χ² 735 / p 3e-162 | 5.9 EB05 5.2 · IC025 +2.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.8 · ♀ 92% (drug 64%) | no trial data cached |
| Decreased appetite (loss of appetite) | 169 | 4.6 4.0–5.3ROR 4.8 · χ² 480 / p 1e-106 | 4.6 EB05 4.0 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 4.3 · ♀ 85% (drug 64%) | 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.
- Helicobacter infection — n=123, PRR 77.2
- Folliculitis — n=124, PRR 76.8
- Pemphigus — n=123, PRR 63.2
- Hand deformity — n=125, PRR 61.0
- Pericarditis — n=137, PRR 52.4
- Hypercholesterolaemia — n=71, PRR 47.3
- Synovitis — n=128, PRR 45.1
- Joint range of motion decreased — n=87, PRR 41.4
- Bursitis — n=72, PRR 37.9
- Glossodynia — n=125, PRR 35.5
✓ A hand-written Bradford Hill causality assessment exists for this drug: Acetaminophen (paracetamol) ↔ Liver injury / hepatotoxicity.
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 Acetaminophen and Diphenhydramine?
In FDA FAERS, the most frequently co-reported reaction terms for Acetaminophen and Diphenhydramine are pyrexia, pain, headache, dyspnoea, confusional state, rash. 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 Acetaminophen and Diphenhydramine have an FDA boxed warning?
No. The FDA label retrieved for Acetaminophen and Diphenhydramine has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Acetaminophen and Diphenhydramine 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 004c39cd-b4f4-1cae-e063-6394a90a0697, effective 20251003; matched on
openfda.generic_name.exact:"ACETAMINOPHEN") - 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, 421 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.