Azelastine HCL side effects: what 1,425 FDA adverse event reports show
Drug class
H 1 -receptor antagonist
Brand names
Azelastine Hydrochloride
Who reports
1,425 reports · 45% serious · 76 with death outcome · 65% female
Used for
Azelastine hydrochloride (HCl) nasal spray, 0.1% is indicated for the treatment of the symptoms of seasonal allergic rhinitis in adults and pediatric patients 5 years and older, and for the treatment of the symptoms of vasomotor rhinitis in adults and adolescent patients 12 years and older.
What it is
Azelastine HCl nasal spray, 0.1%, 137 micrograms (mcg), is an antihistamine formulated as a metered-spray solution for intranasal administration. Azelastine HCl, USP occurs as a white, almost odorless, crystalline powder with a bitter taste. It has a molecular weight of 418.37.
Boxed warning
None in the current label
Causality screen of the 16 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 flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 11 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 |
|---|---|---|---|---|---|---|
| Sneezing | 21 | 13.8 9.0–21.1ROR 14.0 · χ² 237 / p 9e-54 | 13.2 EB05 8.6 · IC025 +2.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.2 · 95% consumer | no trial data cached |
| Sinus disorder | 18 | 13.3 8.4–21.1ROR 13.5 · χ² 193 / p 3e-44 | 12.5 EB05 7.8 · IC025 +2.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 18.3 | no trial data cached |
| Seasonal allergy | 11 | 11.5 6.4–20.6ROR 11.5 · χ² 95 / p 1e-22 | 9.6 EB05 5.1 · IC025 +2.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=1 | no trial data cached |
| Product use complaint | 11 | 10.4 5.8–18.8ROR 10.5 · χ² 85 / p 2e-20 | 8.5 EB05 4.7 · IC025 +1.9 3/3 methods agree | Reporting / coding artifact | serious n=2 | no trial data cached |
| Drug effective for unapproved indication | 16 | 8.1 4.9–13.1ROR 8.1 · χ² 92 / p 4e-22 | 6.9 EB05 4.4 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | – | no trial data cached |
| Blood count abnormal | 8 | 7.6 3.8–15.3ROR 7.7 · χ² 40 / p 1e-10 | 5.7 EB05 3.0 · IC025 +1.2 3/3 methods agree | Lab value / disease marker | serious PRR 8.5 | no trial data cached |
| Body height decreased | 5 | 6.8 2.8–16.3ROR 6.8 · χ² 19 / p 6e-6 | 4.5 EB05 2.1 · IC025 +0.6 3/3 methods agree | Not in label — unassessed | serious n=3 | no trial data cached |
| Product prescribing issue | 8 | 5.8 2.9–11.5ROR 5.8 · χ² 27 / p 1e-7 | 4.5 EB05 2.5 · IC025 +1.0 3/3 methods agree | Reporting / coding artifact | – | no trial data cached |
| Thyroid disorder | 6 | 5.7 2.6–12.7ROR 5.7 · χ² 19 / p 7e-6 | 4.2 EB05 2.1 · IC025 +0.7 3/3 methods agree | Not in label — unassessed | serious PRR 8.4 | no trial data cached |
| Middle insomnia | 7 | 5.5 2.6–11.6ROR 5.6 · χ² 22 / p 2e-6 | 4.2 EB05 2.2 · IC025 +0.8 3/3 methods agree | Not in label — unassessed | serious PRR 6.6 | no trial data cached |
| Tooth disorder | 8 | 5.3 2.6–10.5ROR 5.3 · χ² 24 / p 6e-7 | 4.2 EB05 2.3 · IC025 +0.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.9 | no trial data cached |
| Anosmia (loss of smell) | 5 | 5.1 2.1–12.2ROR 5.1 · χ² 13 / p 2e-4 | 3.7 EB05 1.8 · IC025 +0.3 | Not in label — unassessed | serious n=2 | no trial data cached |
| Pharyngeal oedema | 5 | 4.7 2.0–11.3ROR 4.7 · χ² 11 / p 4e-4 | 3.5 EB05 1.7 · IC025 +0.3 | Not in label — unassessed | serious PRR 6.3 | no trial data cached |
| Expired product administered | 10 | 4.4 2.4–8.2ROR 4.5 · χ² 23 / p 7e-7 | 3.8 EB05 2.2 · IC025 +0.9 3/3 methods agree | Reporting / coding artifact | – | no trial data cached |
| Product dose omission | 19 | 4.2 2.7–6.6ROR 4.3 · χ² 44 / p 2e-11 | 3.9 EB05 2.6 · IC025 +1.2 3/3 methods agree | Reporting / coding artifact | serious PRR 5.8 | no trial data cached |
| Eye pruritus | 8 | 3.6 1.8–7.1ROR 3.6 · χ² 12 / p 2e-4 | 3.1 EB05 1.7 · IC025 +0.4 | Labeled (related wording) related wording | serious PRR 4.2 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
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 |
|---|---|---|---|---|---|---|
| Sneezing | 21 | 13.8 9.0–21.1ROR 14.0 · χ² 237 / p 9e-54 | 13.2 EB05 8.6 · IC025 +2.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.2 · 95% consumer | no trial data cached |
| Product dose omission | 19 | 4.2 2.7–6.6ROR 4.3 · χ² 44 / p 2e-11 | 3.9 EB05 2.6 · IC025 +1.2 3/3 methods agree | Reporting / coding artifact | serious PRR 5.8 | no trial data cached |
| Sinus disorder | 18 | 13.3 8.4–21.1ROR 13.5 · χ² 193 / p 3e-44 | 12.5 EB05 7.8 · IC025 +2.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 18.3 | no trial data cached |
| Drug effective for unapproved indication | 16 | 8.1 4.9–13.1ROR 8.1 · χ² 92 / p 4e-22 | 6.9 EB05 4.4 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | – | no trial data cached |
| Product use complaint | 11 | 10.4 5.8–18.8ROR 10.5 · χ² 85 / p 2e-20 | 8.5 EB05 4.7 · IC025 +1.9 3/3 methods agree | Reporting / coding artifact | serious n=2 | no trial data cached |
| Seasonal allergy | 11 | 11.5 6.4–20.6ROR 11.5 · χ² 95 / p 1e-22 | 9.6 EB05 5.1 · IC025 +2.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=1 | no trial data cached |
| Injection site bruising | 10 | 1.9 1.0–3.5ROR 1.9 · χ² 3 / p 0.037 | 1.8 EB05 1.1 · IC025 -0.2 PRR-only: not supported by EBGM or IC | Not in label — unassessed | serious PRR 7.2 | no trial data cached |
| Expired product administered | 10 | 4.4 2.4–8.2ROR 4.5 · χ² 23 / p 7e-7 | 3.8 EB05 2.2 · IC025 +0.9 3/3 methods agree | Reporting / coding artifact | – | no trial data cached |
| Eye pruritus | 8 | 3.6 1.8–7.1ROR 3.6 · χ² 12 / p 2e-4 | 3.1 EB05 1.7 · IC025 +0.4 | Labeled (related wording) related wording | serious PRR 4.2 | no trial data cached |
| Tooth disorder | 8 | 5.3 2.6–10.5ROR 5.3 · χ² 24 / p 6e-7 | 4.2 EB05 2.3 · IC025 +0.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 2.9 | no trial data cached |
| Product prescribing issue | 8 | 5.8 2.9–11.5ROR 5.8 · χ² 27 / p 1e-7 | 4.5 EB05 2.5 · IC025 +1.0 3/3 methods agree | Reporting / coding artifact | – | no trial data cached |
| Blood count abnormal | 8 | 7.6 3.8–15.3ROR 7.7 · χ² 40 / p 1e-10 | 5.7 EB05 3.0 · IC025 +1.2 3/3 methods agree | Lab value / disease marker | serious PRR 8.5 | no trial data cached |
| Middle insomnia | 7 | 5.5 2.6–11.6ROR 5.6 · χ² 22 / p 2e-6 | 4.2 EB05 2.2 · IC025 +0.8 3/3 methods agree | Not in label — unassessed | serious PRR 6.6 | no trial data cached |
| Thyroid disorder | 6 | 5.7 2.6–12.7ROR 5.7 · χ² 19 / p 7e-6 | 4.2 EB05 2.1 · IC025 +0.7 3/3 methods agree | Not in label — unassessed | serious PRR 8.4 | no trial data cached |
| Pharyngeal oedema | 5 | 4.7 2.0–11.3ROR 4.7 · χ² 11 / p 4e-4 | 3.5 EB05 1.7 · IC025 +0.3 | Not in label — unassessed | serious PRR 6.3 | no trial data cached |
Unlabeled candidate signals
Every screened signal with n ≥ 20 was either labeled, an indication term, or an artifact pattern — no unlabeled candidate stood out in the top signals.
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 Azelastine?
In FDA FAERS, the most frequently co-reported reaction terms for Azelastine are sneezing, sinus disorder, drug effective for unapproved indication, seasonal allergy, injection site bruising, eye pruritus. 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 Azelastine have an FDA boxed warning?
No. The FDA label retrieved for Azelastine has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Azelastine 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 7902605c-944a-4d7e-a7d4-eb4a71bcacdb, effective 20181018; matched on
openfda.generic_name.exact:"AZELASTINE") - 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, 27 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.