Haloperidol side effects: what 24,153 FDA adverse event reports show
Drug class
Typical Antipsychotic
Who reports
24,153 reports · 93% serious · 3,987 with death outcome · 44% female
Used for
Haloperidol tablets are indicated for use in the management of manifestations of psychotic disorders. Haloperidol tablets are indicated for the control of tics and vocal utterances of Tourette's Disorder in children and adults. Haloperidol tablets are effective for the treatment of severe behavior problems in children of combative, explosive hyperexcitability (which cannot be accounted for by immediate provocation).
What it is
DESCRIPTION Haloperidol, USP is the first of the butyrophenone series of major tranquilizers. The chemical designation is 4-[4-( p -chloro-phenyl)-4-hydroxypiperidino]-4'-fluorobutyrophenone a.
Boxed warning
WARNING Increased Mortality in Elderly Patients with Dementia-Related Psychosis Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Analyses of sevente.
Causality screen of the 40 strongest signals
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). 1,140 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 |
|---|---|---|---|---|---|---|
| Myocardial reperfusion injury | 16 | 760.7 388.0–1,491.5ROR 761.2 · calibrated p 2e-13 ✓ | 272.2 EB05 177.6 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=16 | not reported in cached trials |
| Paroxysmal perceptual alteration | 27 | 700.2 421.1–1,164.2ROR 701.0 · calibrated p 5e-14 ✓ | 302.8 EB05 218.6 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=27 · 100% clinician | not reported in cached trials |
| Encephalitis toxic | 19 | 266.6 159.3–446.0ROR 266.8 · calibrated p 4e-10 ✓ | 169.2 EB05 114.5 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=19 | not reported in cached trials |
| Antipsychotic drug level below therapeutic | 158 | 256.1 214.5–305.8ROR 257.8 · calibrated p 5e-11 ✓ | 192.8 EB05 168.8 · IC025 +6.7 3/3 methods agree | Lab value / disease marker | serious n=158 · ♀ 7% (drug 44%) · 90% clinician | not reported in cached trials |
| Malignant catatonia | 54 | 229.9 170.3–310.4ROR 230.4 · calibrated p 3e-10 ✓ | 170.6 EB05 135.7 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious n=54 · 100% clinician | not reported in cached trials |
| Delusion of grandeur | 79 | 186.2 146.1–237.5ROR 186.8 · calibrated p 1e-9 ✓ | 147.7 EB05 122.3 · IC025 +5.9 3/3 methods agree | Not in label — unassessed | serious n=79 · ♀ 0% (drug 44%) · 95% clinician | not reported in cached trials |
| Refusal of examination | 21 | 164.9 103.4–263.0ROR 165.0 · calibrated p 1e-8 ✓ | 123.2 EB05 85.0 · IC025 +4.3 3/3 methods agree | Reporting / coding artifact | serious n=21 · 100% clinician | not reported in cached trials |
| Spasmodic dysphonia | 41 | 140.3 100.9–195.2ROR 140.6 · calibrated p 2e-8 ✓ | 114.4 EB05 87.9 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious n=41 · ♀ 0% (drug 44%) · 100% clinician | not reported in cached trials |
| Neuroleptic malignant syndrome | 1,630 | 138.0 131.2–145.2ROR 147.9 · calibrated p 5e-9 ✓ | 118.8 EB05 114.1 · IC025 +6.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 73.4 · 93% clinician | not reported in cached trials |
| Waxy flexibility | 21 | 117.5 74.5–185.3ROR 117.6 · calibrated p 1e-7 ✓ | 94.7 EB05 65.4 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=21 · 100% clinician | not reported in cached trials |
| Cogwheel rigidity | 104 | 95.1 77.7–116.4ROR 95.5 · calibrated p 2e-7 ✓ | 84.4 EB05 71.6 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious n=99 · 96% clinician | not reported in cached trials |
| Disinhibition | 153 | 91.1 77.1–107.5ROR 91.6 · calibrated p 3e-7 ✓ | 81.6 EB05 71.3 · IC025 +5.8 3/3 methods agree | Not in label — unassessed | serious n=151 · ♀ 0% (drug 44%) | not reported in cached trials |
| Catatonia | 435 | 79.0 71.7–87.1ROR 80.4 · calibrated p 6e-7 ✓ | 72.2 EB05 66.7 · IC025 +5.9 3/3 methods agree | Not in label — unassessed | serious n=424 · 94% clinician | not reported in cached trials |
| Echolalia | 25 | 73.5 48.9–110.6ROR 73.6 · calibrated p 3e-6 ✓ | 64.6 EB05 46.0 · IC025 +4.2 3/3 methods agree | Not in label — unassessed | serious n=25 · ♀ 67% (drug 44%) | not reported in cached trials |
| Oscillopsia | 18 | 64.5 39.9–104.0ROR 64.5 · calibrated p 8e-6 ✓ | 56.6 EB05 37.9 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=18 | not reported in cached trials |
| Oromandibular dystonia | 49 | 63.2 47.3–84.5ROR 63.4 · calibrated p 5e-6 ✓ | 57.7 EB05 45.4 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious n=46 · 92% clinician | not reported in cached trials |
| Colonic pseudo-obstruction | 19 | 62.5 39.3–99.6ROR 62.6 · calibrated p 9e-6 ✓ | 55.3 EB05 37.4 · IC025 +3.8 3/3 methods agree | Not in label — unassessed | serious n=19 | not reported in cached trials |
| Anticholinergic syndrome | 105 | 61.2 50.2–74.6ROR 61.5 · calibrated p 4e-6 ✓ | 56.6 EB05 48.1 · IC025 +5.2 3/3 methods agree | Labeled (related wording) related wording | serious n=105 | not reported in cached trials |
| Neglect of personal appearance | 16 | 60.9 36.7–101.0ROR 60.9 · calibrated p 1e-5 ✓ | 53.5 EB05 34.9 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=15 | not reported in cached trials |
| Breathing-related sleep disorder | 15 | 57.8 34.3–97.5ROR 57.9 · calibrated p 2e-5 ✓ | 50.9 EB05 32.8 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=15 | not reported in cached trials |
| Visceral congestion | 28 | 52.1 35.6–76.3ROR 52.1 · calibrated p 2e-5 ✓ | 47.7 EB05 34.6 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=28 · ♀ 0% (drug 44%) · 100% clinician | not reported in cached trials |
| Psychotic symptom | 113 | 50.9 42.1–61.5ROR 51.1 · calibrated p 1e-5 ✓ | 47.7 EB05 40.8 · IC025 +5.0 3/3 methods agree | Labeled adverse reaction exact term | serious n=112 · 94% clinician | not reported in cached trials |
| Foetal arrhythmia | 15 | 50.7 30.1–85.4ROR 50.8 · calibrated p 4e-5 ✓ | 45.4 EB05 29.2 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious n=15 | not reported in cached trials |
| Grandiosity | 20 | 50.5 32.2–79.2ROR 50.5 · calibrated p 3e-5 ✓ | 45.8 EB05 31.3 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=20 | not reported in cached trials |
| Schizophrenia, paranoid type | 20 | 50.3 32.1–79.0ROR 50.4 · calibrated p 3e-5 ✓ | 45.7 EB05 31.2 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious n=20 | not reported in cached trials |
| Resting tremor | 35 | 49.4 35.2–69.5ROR 49.5 · calibrated p 2e-5 ✓ | 45.7 EB05 34.3 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=35 · ♀ 22% (drug 44%) | not reported in cached trials |
| Protrusion tongue | 30 | 47.5 32.9–68.5ROR 47.5 · calibrated p 3e-5 ✓ | 43.9 EB05 32.2 · IC025 +4.1 3/3 methods agree | Labeled (related wording) related wording | serious n=27 | not reported in cached trials |
| Drug-genetic interaction | 17 | 47.4 29.1–77.2ROR 47.4 · calibrated p 5e-5 ✓ | 43.0 EB05 28.4 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | serious n=17 | not reported in cached trials |
| Water intoxication | 26 | 46.5 31.4–69.1ROR 46.6 · calibrated p 4e-5 ✓ | 42.9 EB05 30.8 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=26 | not reported in cached trials |
| Extrapyramidal disorder | 1,237 | 45.0 42.6–47.6ROR 47.4 · calibrated p 2e-5 ✓ | 42.8 EB05 40.8 · IC025 +5.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 28.1 · 94% clinician | NCT01211522: 1/192 (0.5%) on Haloperidol; 1/184 (0.5%) control (serious AE) |
| Oculogyric crisis | 103 | 44.6 36.6–54.4ROR 44.8 · calibrated p 3e-5 ✓ | 42.2 EB05 35.8 · IC025 +4.8 3/3 methods agree | Labeled adverse reaction exact term | serious n=99 | not reported in cached trials |
| Sexually inappropriate behaviour | 22 | 43.6 28.4–66.9ROR 43.6 · calibrated p 7e-5 ✓ | 40.2 EB05 28.0 · IC025 +3.7 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=21 · 100% clinician | not reported in cached trials |
| Schizoaffective disorder | 85 | 43.2 34.7–53.7ROR 43.3 · calibrated p 4e-5 ✓ | 40.8 EB05 34.0 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious n=82 | not reported in cached trials |
| Emotional poverty | 81 | 42.0 33.6–52.5ROR 42.1 · calibrated p 5e-5 ✓ | 39.7 EB05 33.0 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=80 · ♀ 0% (drug 44%) | not reported in cached trials |
| Lymphocyte count abnormal | 52 | 41.9 31.7–55.3ROR 42.0 · calibrated p 5e-5 ✓ | 39.4 EB05 31.2 · IC025 +4.4 3/3 methods agree | Lab value / disease marker | serious n=52 · ♀ 0% (drug 44%) · 90% clinician | not reported in cached trials |
| Akathisia (inner restlessness) | 623 | 41.5 38.3–44.9ROR 42.6 · calibrated p 4e-5 ✓ | 39.6 EB05 37.0 · IC025 +5.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 33.3 | not reported in cached trials |
| Parkinsonian gait | 28 | 40.9 28.0–59.7ROR 40.9 · calibrated p 8e-5 ✓ | 38.1 EB05 27.7 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=28 | not reported in cached trials |
| Mutism | 65 | 40.9 31.9–52.4ROR 41.0 · calibrated p 6e-5 ✓ | 38.6 EB05 31.4 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | serious n=65 · 100% clinician | not reported in cached trials |
| Blunted affect | 31 | 38.8 27.1–55.6ROR 38.8 · calibrated p 1e-4 ✓ | 36.4 EB05 26.9 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=31 | not reported in cached trials |
| Schizophrenia | 515 | 38.4 35.2–41.9ROR 39.2 · calibrated p 6e-5 ✓ | 36.7 EB05 34.1 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious PRR 23.3 | not reported in cached trials |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Haloperidol 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 (1 of 40 signal terms matched).
- NCT01211522 — The Modifying the Impact of ICU-Associated Neurological Dysfunction-USA (MIND-USA) Study (N=566, PHASE3; 4 AE terms posted; arms: Haloperidol; Ziprasidone; Placebo)
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) | 2,157 | 1.4 1.4–1.5ROR 1.5 · calibrated p 0.618 | 1.4 EB05 1.4 · IC025 +0.4 | Reporting / coding artifact | serious PRR 2.3 | not reported in cached trials |
| Drug interaction | 1,690 | 9.3 8.9–9.8ROR 10.0 · calibrated p 0.033 ✓ | 9.2 EB05 8.9 · IC025 +3.1 3/3 methods agree | Reporting / coding artifact | serious PRR 6.3 · 93% clinician | not reported in cached trials |
| Neuroleptic malignant syndrome | 1,630 | 138.0 131.2–145.2ROR 147.9 · calibrated p 5e-9 ✓ | 118.8 EB05 114.1 · IC025 +6.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 73.4 · 93% clinician | not reported in cached trials |
| Off label use (used outside approved label) | 1,411 | 1.4 1.3–1.5ROR 1.4 · calibrated p 0.601 | 1.4 EB05 1.4 · IC025 +0.4 | Reporting / coding artifact | serious PRR 1.5 | not reported in cached trials |
| Extrapyramidal disorder | 1,237 | 45.0 42.6–47.6ROR 47.4 · calibrated p 2e-5 ✓ | 42.8 EB05 40.8 · IC025 +5.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 28.1 · 94% clinician | NCT01211522: 1/192 (0.5%) on Haloperidol; 1/184 (0.5%) control (serious AE) |
| Weight increased (weight gain) | 1,226 | 4.8 4.5–5.1ROR 5.0 · calibrated p 0.234 | 4.8 EB05 4.5 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 5.3 | not reported in cached trials |
| Toxicity to various agents | 1,028 | 5.3 5.0–5.7ROR 5.5 · calibrated p 0.184 | 5.3 EB05 5.0 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 3.4 · 95% clinician | not reported in cached trials |
| Agitation | 873 | 10.4 9.7–11.1ROR 10.8 · calibrated p 0.025 ✓ | 10.3 EB05 9.7 · IC025 +3.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.1 | not reported in cached trials |
| Somnolence (drowsiness) | 825 | 3.6 3.3–3.8ROR 3.7 · calibrated p 0.446 | 3.6 EB05 3.4 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.6 | not reported in cached trials |
| Pyrexia (fever) | 814 | 2.0 1.9–2.2ROR 2.1 · calibrated p 0.987 | 2.0 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | serious PRR 1.6 | not reported in cached trials |
| Condition aggravated | 807 | 2.3 2.2–2.5ROR 2.4 · calibrated p 0.871 | 2.3 EB05 2.2 · IC025 +1.1 3/3 methods agree | Reporting / coding artifact | serious PRR 2.1 · 91% clinician | not reported in cached trials |
| Delirium | 775 | 19.9 18.5–21.3ROR 20.5 · calibrated p 0.002 ✓ | 19.5 EB05 18.3 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious PRR 12.2 · 91% clinician | not reported in cached trials |
| Confusional state (confusion) | 749 | 4.0 3.8–4.3ROR 4.1 · calibrated p 0.355 | 4.0 EB05 3.8 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.0 | not reported in cached trials |
| Vomiting | 723 | 1.3 1.2–1.4ROR 1.3 · calibrated p 0.542 | 1.3 EB05 1.3 · IC025 +0.3 | Labeled adverse reaction exact term | serious PRR 1.2 | not reported in cached trials |
| Death | 716 | 0.7 0.7–0.8ROR 0.7 · calibrated p 0.137 | 0.7 EB05 0.7 · IC025 -0.6 PRR-only: not supported by EBGM or IC | Outcome field, not a reaction boxed warning mentions mortality | serious PRR 0.4 | 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.
- Paroxysmal perceptual alteration — n=27, PRR 700.2
- Malignant catatonia — n=54, PRR 229.9
- Delusion of grandeur — n=79, PRR 186.2
- Spasmodic dysphonia — n=41, PRR 140.3
- Waxy flexibility — n=21, PRR 117.5
- Cogwheel rigidity — n=104, PRR 95.1
- Disinhibition — n=153, PRR 91.1
- Catatonia — n=435, PRR 79.0
- Echolalia — n=25, PRR 73.5
- Oromandibular dystonia — n=49, PRR 63.2
✓ A hand-written Bradford Hill causality assessment exists for this drug: Haloperidol ↔ QT prolongation / torsades.
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 Haloperidol?
In FDA FAERS, the most frequently co-reported reaction terms for Haloperidol are neuroleptic malignant syndrome, extrapyramidal disorder, weight increased, toxicity to various agents, agitation, somnolence. 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 Haloperidol have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: WARNING Increased Mortality in Elderly Patients with Dementia-Related Psychosis Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Analyses of sevente.
Do FAERS signals prove that Haloperidol 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 00bb61c8-db35-4c04-9ef7-47d447d2496b, effective 20241115; matched on
openfda.generic_name.exact:"HALOPERIDOL") - 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, 1,180 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
HALOPERIDOL, 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.