Drug · FAERS side-effect profile with label screen
Meclizine Hydrocloride side effects: what 2,719 FDA adverse event reports show
Drug class
Not stated in label
Brand names
Meclizine Hydrochloride
openFDA label
Who reports
2,719 reports · 50% serious · 177 with death outcome · 77% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Meclizine hydrochloride is indicated for the treatment of vertigo associated with diseases affecting the vestibular system in adults. Meclizine hydrochloride is indicated for the treatment of vertigo associated with diseases affecting the vestibular system in adults ( 1 ).
FDA label, Indications and Usage
What it is
Meclizine hydrochloride, USP a histamine (H1) receptor antagonist, is a white or slightly yellowish, crystalline powder. It has the following structural formula:
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 1Reporting / coding artifact 6Not in label — unassessed 33
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.
- 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. 182 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 |
|---|---|---|---|---|---|---|
| Seasonal allergy | 49 | 26.8 20.3–35.4ROR 27.3 · χ² 1,188 / p 1e-260 | 26.5 EB05 20.8 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=36 · 78% consumer | no trial data cached |
| Infusion site pain | 38 | 23.0 16.7–31.5ROR 23.3 · χ² 775 / p 8e-171 | 22.7 EB05 17.2 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=24 · 76% consumer | no trial data cached |
| Vertigo (spinning dizziness) | 116 | 14.7 12.3–17.5ROR 15.3 · χ² 1,465 / p <1e-300 | 14.6 EB05 12.5 · IC025 +3.5 3/3 methods agree | Likely indication confounding term in indications | serious PRR 14.7 | no trial data cached |
| Initial insomnia | 13 | 9.8 5.7–16.9ROR 9.9 · χ² 94 / p 1e-22 | 8.2 EB05 4.8 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious n=6 | no trial data cached |
| Brain fog | 18 | 9.5 6.0–15.1ROR 9.6 · χ² 129 / p 4e-30 | 8.3 EB05 5.3 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 14.2 | no trial data cached |
| Insurance issue | 18 | 9.3 5.9–14.8ROR 9.4 · χ² 126 / p 2e-29 | 8.2 EB05 5.2 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 18.7 | no trial data cached |
| Anhedonia | 32 | 9.3 6.6–13.1ROR 9.4 · χ² 229 / p 5e-52 | 8.6 EB05 6.3 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 11.6 · ♀ 44% (drug 77%) | no trial data cached |
| Laryngitis | 13 | 9.2 5.4–15.9ROR 9.3 · χ² 87 / p 5e-21 | 7.6 EB05 4.5 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious n=8 | no trial data cached |
| Eye pain | 64 | 8.9 7.0–11.4ROR 9.1 · χ² 443 / p 1e-98 | 8.6 EB05 6.9 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 2.6 · 89% consumer | no trial data cached |
| Product dose omission in error | 30 | 8.6 6.0–12.3ROR 8.7 · χ² 194 / p 2e-44 | 7.9 EB05 5.7 · IC025 +2.3 3/3 methods agree | Reporting / coding artifact | serious PRR 25.0 | no trial data cached |
| Respiratory tract infection | 29 | 8.6 6.0–12.4ROR 8.7 · χ² 187 / p 6e-43 | 7.9 EB05 5.6 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 11.4 · 72% consumer | no trial data cached |
| Intervertebral disc degeneration | 10 | 8.3 4.5–15.4ROR 8.3 · χ² 57 / p 2e-14 | 6.5 EB05 3.6 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 8.8 | no trial data cached |
| Eye infection | 12 | 8.2 4.7–14.5ROR 8.3 · χ² 69 / p 4e-17 | 6.7 EB05 3.9 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious n=8 | no trial data cached |
| Product use complaint | 16 | 8.0 4.9–13.0ROR 8.0 · χ² 90 / p 1e-21 | 6.8 EB05 4.3 · IC025 +1.9 3/3 methods agree | Reporting / coding artifact | serious n=10 | no trial data cached |
| Impaired gastric emptying | 13 | 7.9 4.6–13.5ROR 7.9 · χ² 71 / p 2e-17 | 6.5 EB05 3.9 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 10.3 | no trial data cached |
| Sinus disorder | 20 | 7.8 5.0–12.0ROR 7.8 · χ² 111 / p 3e-26 | 6.8 EB05 4.6 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 12.7 | no trial data cached |
| Skin haemorrhage | 14 | 7.5 4.4–12.6ROR 7.5 · χ² 72 / p 1e-17 | 6.2 EB05 3.9 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious n=8 | no trial data cached |
| Gastroenteritis viral | 17 | 7.2 4.5–11.6ROR 7.3 · χ² 85 / p 1e-20 | 6.2 EB05 4.1 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 10.4 | no trial data cached |
| Skin laceration | 10 | 7.1 3.8–13.2ROR 7.2 · χ² 47 / p 4e-12 | 5.6 EB05 3.2 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 9.6 | no trial data cached |
| Osteopenia | 14 | 7.1 4.2–11.9ROR 7.1 · χ² 67 / p 1e-16 | 5.9 EB05 3.7 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 9.0 | no trial data cached |
| Nocturia (night-time urination) | 11 | 7.0 3.9–12.6ROR 7.0 · χ² 51 / p 5e-13 | 5.6 EB05 3.3 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 12.7 | no trial data cached |
| Limb injury | 24 | 6.8 4.6–10.2ROR 6.9 · χ² 114 / p 8e-27 | 6.1 EB05 4.3 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 8.6 | no trial data cached |
| Illness | 88 | 6.7 5.5–8.3ROR 6.9 · χ² 427 / p 4e-95 | 6.5 EB05 5.5 · IC025 +2.4 3/3 methods agree | Reporting / coding artifact | serious PRR 11.1 | no trial data cached |
| Ear infection | 23 | 6.7 4.4–10.0ROR 6.7 · χ² 105 / p 5e-25 | 6.0 EB05 4.2 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 11.7 · ♀ 100% (drug 77%) | no trial data cached |
| Candida infection (yeast infection) | 14 | 6.5 3.8–10.9ROR 6.5 · χ² 59 / p 7e-15 | 5.4 EB05 3.4 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 10.0 | no trial data cached |
| Productive cough (cough with phlegm) | 39 | 6.3 4.6–8.7ROR 6.4 · χ² 171 / p 3e-39 | 5.9 EB05 4.5 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 8.2 · 72% consumer | no trial data cached |
| Product dose omission issue | 229 | 6.2 5.5–7.0ROR 6.7 · χ² 1,005 / p 6e-221 | 6.1 EB05 5.5 · IC025 +2.4 3/3 methods agree | Reporting / coding artifact | serious PRR 14.6 · 76% consumer | no trial data cached |
| Sleep disorder due to a general medical condition | 13 | 6.2 3.6–10.7ROR 6.2 · χ² 52 / p 4e-13 | 5.2 EB05 3.2 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 8.8 | no trial data cached |
| Skin fissures | 15 | 6.1 3.7–10.1ROR 6.1 · χ² 59 / p 7e-15 | 5.2 EB05 3.4 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious n=10 | no trial data cached |
| Head injury | 25 | 6.1 4.1–9.0ROR 6.1 · χ² 102 / p 3e-24 | 5.5 EB05 3.9 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 7.2 · 80% consumer | no trial data cached |
| Musculoskeletal chest pain | 12 | 6.0 3.4–10.5ROR 6.0 · χ² 45 / p 1e-11 | 4.9 EB05 3.0 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 8.2 | no trial data cached |
| Ankle fracture | 12 | 6.0 3.4–10.5ROR 6.0 · χ² 45 / p 1e-11 | 4.9 EB05 3.0 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 7.2 | no trial data cached |
| Sinusitis | 79 | 5.9 4.8–7.4ROR 6.1 · χ² 319 / p 9e-72 | 5.7 EB05 4.7 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 9.8 | no trial data cached |
| Upper respiratory tract infection (cold/sinus infection) | 35 | 5.8 4.2–8.1ROR 5.9 · χ² 136 / p 1e-31 | 5.4 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 9.9 | no trial data cached |
| Joint injury | 16 | 5.8 3.5–9.4ROR 5.8 · χ² 58 / p 1e-14 | 5.0 EB05 3.3 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 7.6 | no trial data cached |
| Balance disorder | 64 | 5.7 4.5–7.3ROR 5.8 · χ² 244 / p 3e-55 | 5.5 EB05 4.4 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 6.5 | no trial data cached |
| Sleep apnoea syndrome | 14 | 5.6 3.3–9.5ROR 5.7 · χ² 49 / p 1e-12 | 4.8 EB05 3.1 · IC025 +1.4 3/3 methods agree | Not in label — unassessed | serious PRR 5.6 | no trial data cached |
| Economic problem | 11 | 5.5 3.0–9.9ROR 5.5 · χ² 36 / p 9e-10 | 4.6 EB05 2.7 · IC025 +1.2 3/3 methods agree | Reporting / coding artifact | serious PRR 7.0 | no trial data cached |
| Drug effect less than expected | 10 | 5.5 2.9–10.1ROR 5.5 · χ² 32 / p 7e-9 | 4.5 EB05 2.6 · IC025 +1.1 3/3 methods agree | Reporting / coding artifact | serious n=3 | no trial data cached |
| Chronic kidney disease | 54 | 5.4 4.2–7.1ROR 5.5 · χ² 191 / p 9e-44 | 5.2 EB05 4.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.4 · ♀ 46% (drug 77%) | 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 |
|---|---|---|---|---|---|---|
| Dizziness | 284 | 4.4 3.9–4.9ROR 4.8 · χ² 759 / p 3e-167 | 4.4 EB05 4.0 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 5.2 · 70% consumer | no trial data cached |
| Product dose omission issue | 229 | 6.2 5.5–7.0ROR 6.7 · χ² 1,005 / p 6e-221 | 6.1 EB05 5.5 · IC025 +2.4 3/3 methods agree | Reporting / coding artifact | serious PRR 14.6 · 76% consumer | no trial data cached |
| Fall | 188 | 4.4 3.8–5.0ROR 4.6 · χ² 490 / p 7e-109 | 4.3 EB05 3.8 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 4.7 | no trial data cached |
| Cough | 132 | 3.6 3.1–4.3ROR 3.8 · χ² 253 / p 4e-57 | 3.6 EB05 3.1 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 | no trial data cached |
| Vertigo (spinning dizziness) | 116 | 14.7 12.3–17.5ROR 15.3 · χ² 1,465 / p <1e-300 | 14.6 EB05 12.5 · IC025 +3.5 3/3 methods agree | Likely indication confounding term in indications | serious PRR 14.7 | no trial data cached |
| Urinary tract infection (bladder infection) | 111 | 5.0 4.2–6.0ROR 5.2 · χ² 357 / p 7e-80 | 4.9 EB05 4.2 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 5.8 · 71% consumer | no trial data cached |
| Covid-19 | 109 | 4.7 3.9–5.7ROR 4.9 · χ² 321 / p 5e-72 | 4.7 EB05 4.0 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 6.9 | no trial data cached |
| Illness | 88 | 6.7 5.5–8.3ROR 6.9 · χ² 427 / p 4e-95 | 6.5 EB05 5.5 · IC025 +2.4 3/3 methods agree | Reporting / coding artifact | serious PRR 11.1 | no trial data cached |
| Feeling abnormal | 85 | 2.7 2.2–3.4ROR 2.8 · χ² 92 / p 5e-22 | 2.7 EB05 2.2 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 · 79% consumer | no trial data cached |
| Sinusitis | 79 | 5.9 4.8–7.4ROR 6.1 · χ² 319 / p 9e-72 | 5.7 EB05 4.7 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 9.8 | no trial data cached |
| Nasopharyngitis (common cold) | 78 | 3.3 2.6–4.0ROR 3.3 · χ² 120 / p 3e-28 | 3.2 EB05 2.6 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 4.9 | no trial data cached |
| Inappropriate schedule of product administration | 70 | 3.0 2.4–3.8ROR 3.1 · χ² 95 / p 9e-23 | 3.0 EB05 2.5 · IC025 +1.2 3/3 methods agree | Reporting / coding artifact | serious PRR 7.0 · 72% consumer | no trial data cached |
| Tremor (shaking) | 69 | 3.2 2.5–4.0ROR 3.3 · χ² 103 / p 2e-24 | 3.1 EB05 2.6 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 | no trial data cached |
| Balance disorder | 64 | 5.7 4.5–7.3ROR 5.8 · χ² 244 / p 3e-55 | 5.5 EB05 4.4 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 6.5 | no trial data cached |
| Eye pain | 64 | 8.9 7.0–11.4ROR 9.1 · χ² 443 / p 1e-98 | 8.6 EB05 6.9 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 2.6 · 89% consumer | 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.
- Seasonal allergy — n=49, PRR 26.8
- Infusion site pain — n=38, PRR 23.0
- Anhedonia — n=32, PRR 9.3
- Eye pain — n=64, PRR 8.9
- Respiratory tract infection — n=29, PRR 8.6
- Sinus disorder — n=20, PRR 7.8
- Limb injury — n=24, PRR 6.8
- Ear infection — n=23, PRR 6.7
- Productive cough — n=39, PRR 6.3
- Head injury — n=25, PRR 6.1
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 Meclizine Hydrocloride?
In FDA FAERS, the most frequently co-reported reaction terms for Meclizine Hydrocloride are dizziness, fall, cough, vertigo, urinary tract infection, covid-19. 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 Meclizine Hydrocloride have an FDA boxed warning?
No. The FDA label retrieved for Meclizine Hydrocloride has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Meclizine Hydrocloride 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 5c70e61b-a1e6-4981-92e2-1050cee08baa, effective 20201030; matched on
openfda.generic_name.exact:"MECLIZINE HYDROCLORIDE") - 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, 222 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.