zonisamide Side Effects
Also known as: Zonegran
Analysis of 14,210 adverse event reports submitted to the FDA from 2004 to 2025.
Total Reports
14,210
Death-Related
869
6.1% of reports
Hospitalizations
4,400
31.0% of reports
Top Indication
Product Used For Unknown Indication
Most Reported Adverse Reactions
Who Reports Side Effects
Gender Distribution
Age Distribution
Reporting Trend by Year
Reactions in Death Reports
Top reactions reported in 869 reports where death was an outcome. These are voluntarily reported and do not establish causation.
| Reaction | Reports |
|---|---|
| DEATH | 195 |
| COMPLETED SUICIDE | 59 |
| PNEUMONIA ASPIRATION | 55 |
| OFF LABEL USE | 53 |
| RESPIRATORY FAILURE | 41 |
| PNEUMONIA | 39 |
| TOXICITY TO VARIOUS AGENTS | 39 |
| SUDDEN UNEXPLAINED DEATH IN EPILEPSY | 38 |
| CARDIO-RESPIRATORY ARREST | 37 |
| DRUG INEFFECTIVE | 36 |
| CARDIAC ARREST | 34 |
| SEPTIC SHOCK | 33 |
| FOETAL EXPOSURE DURING PREGNANCY | 30 |
| SOMNOLENCE | 28 |
| STATUS EPILEPTICUS | 27 |
| FALL | 26 |
| SEIZURE | 25 |
| SEPSIS | 25 |
| ANXIETY | 23 |
| CONVULSION | 22 |
Reactions in Hospitalization Reports
Top reactions in 4,400 reports where hospitalization was an outcome.
| Reaction | Reports |
|---|---|
| SEIZURE | 449 |
| DRUG INEFFECTIVE | 427 |
| OFF LABEL USE | 253 |
| FALL | 249 |
| CONVULSION | 230 |
| SOMNOLENCE | 229 |
| VOMITING | 224 |
| PNEUMONIA | 219 |
| DRUG INTERACTION | 212 |
| PYREXIA | 201 |
| NAUSEA | 191 |
| DIZZINESS | 172 |
| FATIGUE | 171 |
| EPILEPSY | 154 |
| WEIGHT DECREASED | 154 |
| CONDITION AGGRAVATED | 152 |
| STATUS EPILEPTICUS | 146 |
| HEADACHE | 127 |
| ASTHENIA | 126 |
| DIARRHOEA | 120 |
Nearby — Related Medications
What the FAERS Data Reveals About zonisamide Side Effects
The FDA Adverse Event Reporting System (FAERS) contains 14,210 voluntary reports linked to zonisamide and its brand equivalents (Zonegran), spanning 2004 through 2025. Of those, 869 (6.1%) listed death as an outcome and 4,400 (31.0%) 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, 61% were female and 39% male; age distribution skews toward 18-44, with 3,110 reports in that bracket. The single most reported reaction is drug ineffective with 1,636 submissions, followed by seizure 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.
Read our methodology — how this data is sourced, computed, and verified.