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rifaximin Side Effects

Also known as: Xifaxan

Analysis of 19,891 adverse event reports submitted to the FDA from 2004 to 2025.

Total Reports

19,891

Death-Related

5,855

29.4% of reports

Hospitalizations

7,784

39.1% of reports

Top Indication

Product Used For Unknown Indication

Most Reported Adverse Reactions

DEATH
3,982
HOSPITALISATION
1,704
DIARRHOEA
1,193
OFF LABEL USE
1,133
THERAPY INTERRUPTED
989
AMMONIA INCREASED
831
NAUSEA
802
FATIGUE
779
HEPATIC ENCEPHALOPATHY
762
DRUG INEFFECTIVE
713
CONFUSIONAL STATE
711
INABILITY TO AFFORD MEDICATION
679
HEPATIC CIRRHOSIS
657
INSURANCE ISSUE
623
FALL
607
CONDITION AGGRAVATED
603
DIZZINESS
517
PRODUCT USE IN UNAPPROVED INDICATION
517
HEADACHE
512
PRODUCT USE ISSUE
488

Who Reports Side Effects

Gender Distribution

Female 9,942 (52%)
Male 9,087 (48%)
Unknown 14

Age Distribution

0-17 254 (2%)
18-44 1,356 (10%)
45-64 5,220 (37%)
65-74 4,728 (33%)
75+ 2,637 (19%)

Reporting Trend by Year

2004 2025

Reactions in Death Reports

Top reactions reported in 5,855 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction Reports
DEATH 3,977
HEPATIC CIRRHOSIS 378
HEPATIC FAILURE 329
RENAL FAILURE 251
HOSPITALISATION 208
LIVER DISORDER 176
THERAPY INTERRUPTED 170
HEPATIC ENCEPHALOPATHY 161
HOSPICE CARE 160
PNEUMONIA 144
SEPSIS 124
FALL 118
AMMONIA INCREASED 115
HEPATIC CANCER 112
DRUG INEFFECTIVE 105
DIARRHOEA 98
PRODUCT USE ISSUE 98
INSURANCE ISSUE 94
MULTIPLE ORGAN DYSFUNCTION SYNDROME 92
CONDITION AGGRAVATED 90

Reactions in Hospitalization Reports

Top reactions in 7,784 reports where hospitalization was an outcome.

Reaction Reports
HOSPITALISATION 1,697
AMMONIA INCREASED 696
THERAPY INTERRUPTED 628
HEPATIC ENCEPHALOPATHY 618
CONFUSIONAL STATE 473
FALL 445
INABILITY TO AFFORD MEDICATION 399
DIARRHOEA 398
DEATH 390
INSURANCE ISSUE 358
PNEUMONIA 343
HEPATIC CIRRHOSIS 335
CONDITION AGGRAVATED 316
NAUSEA 297
DYSPNOEA 284
PRODUCT USE ISSUE 280
FATIGUE 273
LIVER DISORDER 264
ASCITES 263
HEPATIC FAILURE 259

Nearby — Related Medications

Compare rifaximin vs alosetron →

What the FAERS Data Reveals About rifaximin Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 19,891 voluntary reports linked to rifaximin and its brand equivalents (Xifaxan), spanning 2004 through 2025. Of those, 5,855 (29.4%) listed death as an outcome and 7,784 (39.1%) 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, 52% were female and 48% male; age distribution skews toward 45-64, with 5,220 reports in that bracket. The single most reported reaction is death with 3,982 submissions, followed by hospitalisation and diarrhoea.

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.