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mirtazapine Side Effects

Also known as: Remeron

Analysis of 87,759 adverse event reports submitted to the FDA from 2003 to 2025.

Total Reports

87,759

Death-Related

13,537

15.4% of reports

Hospitalizations

36,013

41.0% of reports

Top Indication

Product Used For Unknown Indication

Most Reported Adverse Reactions

NAUSEA
4,838
FATIGUE
4,715
DRUG INEFFECTIVE
4,596
FALL
4,027
DIARRHOEA
3,961
OFF LABEL USE
3,836
TOXICITY TO VARIOUS AGENTS
3,703
ANXIETY
3,472
DIZZINESS
3,429
DYSPNOEA
3,394
DEATH
3,322
DRUG INTERACTION
3,249
DEPRESSION
3,210
VOMITING
3,192
HEADACHE
3,058
SOMNOLENCE
2,993
ASTHENIA
2,911
INSOMNIA
2,911
CONFUSIONAL STATE
2,881
PAIN
2,849

Who Reports Side Effects

Gender Distribution

Female 46,485 (57%)
Male 34,180 (42%)
Unknown 236

Age Distribution

0-17 1,687 (3%)
18-44 15,320 (24%)
45-64 21,120 (33%)
65-74 11,897 (18%)
75+ 14,744 (23%)

Reporting Trend by Year

2003 2025

Reactions in Death Reports

Top reactions reported in 13,537 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction Reports
DEATH 3,312
COMPLETED SUICIDE 2,313
TOXICITY TO VARIOUS AGENTS 2,213
DRUG ABUSE 732
OVERDOSE 663
DRUG INTERACTION 632
CARDIO-RESPIRATORY ARREST 621
FATIGUE 598
CARDIAC ARREST 595
PNEUMONIA 572
FALL 570
DYSPNOEA 549
DIARRHOEA 540
NAUSEA 522
ASTHENIA 503
DECREASED APPETITE 470
SEPSIS 465
VOMITING 460
OFF LABEL USE 458
SOMNOLENCE 440

Reactions in Hospitalization Reports

Top reactions in 36,013 reports where hospitalization was an outcome.

Reaction Reports
FALL 2,686
NAUSEA 2,100
DIARRHOEA 1,891
FATIGUE 1,827
DYSPNOEA 1,806
VOMITING 1,786
CONFUSIONAL STATE 1,760
PNEUMONIA 1,616
ASTHENIA 1,614
OFF LABEL USE 1,591
DRUG INEFFECTIVE 1,529
DEPRESSION 1,457
DRUG INTERACTION 1,437
TOXICITY TO VARIOUS AGENTS 1,428
INTENTIONAL OVERDOSE 1,425
HYPOTENSION 1,419
DIZZINESS 1,414
PYREXIA 1,335
SOMNOLENCE 1,327
PAIN 1,290

Nearby — Related Medications

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What the FAERS Data Reveals About mirtazapine Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 87,759 voluntary reports linked to mirtazapine and its brand equivalents (Remeron), spanning 2003 through 2025. Of those, 13,537 (15.4%) listed death as an outcome and 36,013 (41.0%) 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, 57% were female and 42% male; age distribution skews toward 45-64, with 21,120 reports in that bracket. The single most reported reaction is nausea with 4,838 submissions, followed by fatigue and drug ineffective.

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.