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felbamate Side Effects

Also known as: Felbatol

Analysis of 1,714 adverse event reports submitted to the FDA from 2004 to 2025.

Total Reports

1,714

Death-Related

86

5.0% of reports

Hospitalizations

529

30.9% of reports

Top Indication

Product Used For Unknown Indication

Most Reported Adverse Reactions

SEIZURE
345
DRUG INEFFECTIVE
251
CONVULSION
124
OFF LABEL USE
115
SOMNOLENCE
108
CONDITION AGGRAVATED
92
FATIGUE
85
DRUG INTERACTION
71
TOXICITY TO VARIOUS AGENTS
71
VOMITING
70
FALL
60
GENERALISED TONIC-CLONIC SEIZURE
60
DIARRHOEA
59
WEIGHT DECREASED
52
PNEUMONIA
50
DECREASED APPETITE
47
EPILEPSY
47
NAUSEA
46
DIZZINESS
42
PRODUCT USE IN UNAPPROVED INDICATION
42

Who Reports Side Effects

Gender Distribution

Female 694 (52%)
Male 643 (48%)
Unknown 7

Age Distribution

0-17 405 (43%)
18-44 388 (42%)
45-64 117 (13%)
65-74 15 (2%)
75+ 9 (1%)

Reporting Trend by Year

2004 2025

Reactions in Death Reports

Top reactions reported in 86 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction Reports
CARDIAC ARREST 22
DEATH 20
TACHYCARDIA 18
TOXICITY TO VARIOUS AGENTS 18
CIRCULATORY COLLAPSE 14
ELECTROCARDIOGRAM QRS COMPLEX PROLONGED 14
ATRIOVENTRICULAR BLOCK FIRST DEGREE 13
CARDIOTOXICITY 13
ELECTROCARDIOGRAM ST SEGMENT ELEVATION 13
ELECTROCARDIOGRAM REPOLARISATION ABNORMALITY 12
SINUS BRADYCARDIA 12
SYSTOLIC DYSFUNCTION 12
VENTRICULAR HYPOKINESIA 12
UNMASKING OF PREVIOUSLY UNIDENTIFIED DISEASE 11
VENTRICULAR EXTRASYSTOLES 11
SEIZURE 7
SUDDEN UNEXPLAINED DEATH IN EPILEPSY 7
HYPOTENSION 6
METABOLIC ACIDOSIS 6
RESPIRATORY FAILURE 6

Reactions in Hospitalization Reports

Top reactions in 529 reports where hospitalization was an outcome.

Reaction Reports
SEIZURE 109
DRUG INEFFECTIVE 83
CONVULSION 41
OFF LABEL USE 41
TOXICITY TO VARIOUS AGENTS 40
PNEUMONIA 39
VOMITING 36
TACHYCARDIA 35
SOMNOLENCE 33
CONDITION AGGRAVATED 30
DRUG INTERACTION 29
HOSPITALISATION 29
FATIGUE 27
FALL 25
STATUS EPILEPTICUS 22
CARDIAC ARREST 20
DRUG REACTION WITH EOSINOPHILIA AND SYSTEMIC SYMPTOMS 20
PYREXIA 19
ASTHENIA 18
EPILEPSY 18

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What the FAERS Data Reveals About felbamate Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 1,714 voluntary reports linked to felbamate and its brand equivalents (Felbatol), spanning 2004 through 2025. Of those, 86 (5.0%) listed death as an outcome and 529 (30.9%) 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 0-17, with 405 reports in that bracket. The single most reported reaction is seizure with 345 submissions, followed by drug ineffective and convulsion.

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.