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Drug side effects

azelastine Side Effects

The reactions most often reported to the FDA for azelastine (also sold as Astelin, Astepro), with demographics, serious outcomes, and reporting trends.

Data updated 2026-05-15

16,672
FAERS reports

Data from the FDA Adverse Event Reporting System (FAERS), 2004 to 2025. A FAERS report records a temporal association, not proof of cause. See our methodology for how figures are compiled and de-duplicated.

The most commonly reported side effects of azelastine come from 16,672 reports to the FDA, broken down here by frequency, patient demographics, and serious outcomes.

This page analyzes 16,672 reports to the FDA Adverse Event Reporting System (FAERS) for azelastine (Astelin): the reactions reported most often, who reported them, serious outcomes such as hospitalization, and year-over-year trends. A FAERS report does not prove the drug caused the effect, and report volume tracks how widely a drug is used, not how likely an effect is for any one person. Educational information, not medical advice.

Total Reports

16,672

Reports Mentioning Death

522

3.1% of reports — not proof the medicine caused the death

Hospitalizations

2,849

17.1% of reports

Top Indication

Product Used For Unknown Indication

Most Reported Adverse Reactions

TREATMENT FAILURE
1,876
FATIGUE
1,144
HEADACHE
883
NAUSEA
879
DYSPNOEA
836
DIARRHOEA
766
PAIN
755
COUGH
719
SINUSITIS
685
DIZZINESS
615
ASTHMA
544
PNEUMONIA
535
ARTHRALGIA
515
COVID-19
506
FALL
488
RASH
476
PRURITUS
464

Who Reports Side Effects

Gender Distribution

Female 10,573 (68%)
Male 4,923 (32%)
Unknown 11

Age Distribution

0-17 256 (3%)
18-44 1,231 (15%)
45-64 2,969 (37%)
65-74 2,142 (26%)
75+ 1,513 (19%)

Reporting Trend by Year

2004 2025

Reactions in Death Reports

Top reactions reported in 522 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction Reports
DEATH 294
DYSPNOEA 39
PNEUMONIA 35
FALL 24
FATIGUE 24
CARDIAC ARREST 21
CHRONIC OBSTRUCTIVE PULMONARY DISEASE 21
SEPSIS 20
ACUTE KIDNEY INJURY 19
CEREBROVASCULAR ACCIDENT 19
ASTHENIA 18
DIARRHOEA 18
HYPOTENSION 18
PYREXIA 18
RENAL FAILURE 18
DECREASED APPETITE 17
WEIGHT DECREASED 17
MALAISE 16
NAUSEA 16
RESPIRATORY FAILURE 16

Reactions in Hospitalization Reports

Top reactions in 2,849 reports where hospitalization was an outcome.

Reaction Reports
PNEUMONIA 375
DYSPNOEA 286
FATIGUE 282
NAUSEA 258
FALL 251
DIARRHOEA 231
HEADACHE 206
PAIN 195
COUGH 187
ASTHENIA 166
DIZZINESS 166
COVID-19 162
SINUSITIS 159
URINARY TRACT INFECTION 153
MALAISE 144
VOMITING 143
PYREXIA 142
WEIGHT DECREASED 142
HOSPITALISATION 132

Compare azelastine vs budesonide nasal →

What the FAERS Data Reveals About azelastine Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 16,672 voluntary reports linked to azelastine and its brand equivalents (Astelin, Astepro), spanning 2004 through 2025. Of those, 522 (3.1%) listed death as an outcome and 2,849 (17.1%) involved hospitalization. The most common indication reported alongside adverse events was Product Used For Unknown Indication.

Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 68% were female and 32% male; age distribution skews toward 45-64, with 2,969 reports in that bracket. The single most reported reaction is treatment failure with 1,876 submissions, followed by fatigue and headache.

How to read these numbers

FAERS is a signal-detection tool, not a scorecard. Reports are voluntary, and a single case may list multiple suspect drugs, so numbers above should not be read as incidence rates or per-patient risk. Widely prescribed drugs naturally accumulate more reports than niche therapies even when individual risk is low. These aggregates are useful for spotting patterns that merit further pharmacovigilance, not for choosing between medications. This page is for educational reference only and is not medical advice, speak with a licensed clinician about any side-effect concerns.