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metronidazole topical Side Effects

Also known as: MetroGel

Analysis of 45,816 adverse event reports submitted to the FDA from 1999 to 2025.

Total Reports

45,816

Death-Related

5,167

11.3% of reports

Hospitalizations

18,836

41.1% of reports

Top Indication

Product Used For Unknown Indication

Most Reported Adverse Reactions

DRUG INEFFECTIVE
4,365
NAUSEA
3,318
OFF LABEL USE
3,130
DIARRHOEA
2,621
VOMITING
2,211
PYREXIA
2,205
HEADACHE
2,127
PAIN
2,047
ABDOMINAL PAIN
2,009
FATIGUE
1,847
DIZZINESS
1,611
ACUTE KIDNEY INJURY
1,501
CONDITION AGGRAVATED
1,495
DYSPNOEA
1,493
MALAISE
1,430
RASH
1,293
DRUG HYPERSENSITIVITY
1,248
ANAEMIA
1,217
ANXIETY
1,178
CHRONIC KIDNEY DISEASE
1,176

Who Reports Side Effects

Gender Distribution

Female 25,143 (61%)
Male 15,907 (39%)
Unknown 136

Age Distribution

0-17 2,457 (7%)
18-44 9,898 (29%)
45-64 10,392 (31%)
65-74 6,291 (19%)
75+ 4,854 (14%)

Reporting Trend by Year

1999 2025

Reactions in Death Reports

Top reactions reported in 5,167 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction Reports
DEATH 780
DRUG INEFFECTIVE 768
SEPSIS 654
MULTIPLE ORGAN DYSFUNCTION SYNDROME 618
OFF LABEL USE 501
SEPTIC SHOCK 430
GENERAL PHYSICAL HEALTH DETERIORATION 416
VOMITING 411
ABDOMINAL PAIN 407
NAUSEA 397
CONDITION AGGRAVATED 390
PNEUMONIA 341
PYREXIA 340
ASCITES 336
ABDOMINAL DISTENSION 324
RENAL FAILURE 317
ANAEMIA 312
DYSPNOEA 298
CONSTIPATION 293
HYPONATRAEMIA 291

Reactions in Hospitalization Reports

Top reactions in 18,836 reports where hospitalization was an outcome.

Reaction Reports
DRUG INEFFECTIVE 1,884
OFF LABEL USE 1,455
NAUSEA 1,450
PYREXIA 1,378
DIARRHOEA 1,367
ABDOMINAL PAIN 1,230
VOMITING 1,197
PAIN 1,107
ANAEMIA 905
ACUTE KIDNEY INJURY 884
DYSPNOEA 845
HEADACHE 781
MALAISE 780
CONDITION AGGRAVATED 778
WEIGHT DECREASED 742
FATIGUE 703
SEPSIS 703
ASTHENIA 700
PNEUMONIA 685
CONSTIPATION 623

Nearby — Related Medications

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What the FAERS Data Reveals About metronidazole topical Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 45,816 voluntary reports linked to metronidazole topical and its brand equivalents (MetroGel), spanning 1999 through 2025. Of those, 5,167 (11.3%) listed death as an outcome and 18,836 (41.1%) 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, 61% were female and 39% male; age distribution skews toward 45-64, with 10,392 reports in that bracket. The single most reported reaction is drug ineffective with 4,365 submissions, followed by nausea and off label use.

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.