Drug class · FAERS comparison
Anti-epileptic Agent side effects compared: 13 drugs, 475,654 FDA adverse event reports
How to read this page. Report counts are not incidence rates: a drug with more reports is usually older, more widely used or more publicised, not more dangerous.
Signals are screened against each product's FDA label on its own page; a term flagged across most of a class usually reflects the shared mechanism or the shared patient population.
Members
| Drug | FAERS reports | Serious | Death outcome | Boxed warning | Top labeled signals | Unlabeled (unassessed) |
|---|---|---|---|---|---|---|
| Lamotrigine | 130,963 | 72% | 11,279 | boxed | Epilepsy; Stevens-johnson syndrome; Duodenal ulcer perforation | Blepharospasm; Live birth |
| Lamotrigine | 75,488 | 81% | 8,506 | boxed | – | – |
| Lamotrigine Chewable Dispersible (Lamotrigine) | 71,201 | 81% | 8,154 | boxed | Petit mal epilepsy; Sudden unexplained death in epilepsy; Partial seizures with secondary generalisation | Facet joint syndrome; Dysmorphism |
| Lamotirigine (Lamotrigine) | 71,199 | 81% | 8,154 | – | – | – |
| Oxcarbazepine | 31,339 | 76% | 2,175 | – | Epilepsy; Status epilepticus; Petit mal epilepsy | Trigeminal neuralgia; Myoclonic epilepsy |
| Valproic Acid | 31,329 | 94% | 4,621 | boxed | Foetal anticonvulsant syndrome; Myoclonic epilepsy; Congenital nose malformation | Hyperammonaemia; Hyperammonaemic encephalopathy |
| Phenytoin | 20,744 | 90% | 2,979 | – | Status epilepticus; Ataxia; Nystagmus | Inspiratory capacity decreased; Gingival hypertrophy |
| Vigabatrin | 14,490 | 70% | 1,381 | boxed | Drug withdrawal convulsions; Infantile spasms; Status epilepticus | Retinogram abnormal; Tonic convulsion |
| Zonisamide | 10,552 | 77% | 677 | – | Status epilepticus; Sudden unexplained death in epilepsy; Choroidal effusion | Tonic convulsion; Hyperammonaemic encephalopathy |
| Primidone | 10,121 | 66% | 874 | – | Ataxia; Status epilepticus; Nystagmus | Essential tremor; Grand mal convulsion |
| Phenytoin | 3,989 | 83% | 327 | – | Convulsion; Epilepsy; Ataxia | Toxicity to various agents; Pharmaceutical product complaint |
| Ethosuximide | 2,488 | 81% | 63 | – | Seizure; Somnolence; Status epilepticus | Generalised tonic-clonic seizure; Cognitive disorder |
| Felbamate | 1,751 | 71% | 89 | boxed | Convulsion; Somnolence; Epilepsy | Toxicity to various agents; Lethargy |
Class-wide signals (flagged in at least 7 of 13 members)
| Reaction | Members flagged | Median PRR | Reports (sum) | In label |
|---|---|---|---|---|
| Status epilepticus | 8/13 | 38.1 | 2,011 | 8/8 members' labels |
| Myoclonic epilepsy | 8/13 | 37.5 | 886 | 1/8 members' labels |
| Sudden unexplained death in epilepsy | 7/13 | 74.9 | 580 | 3/7 members' labels |
| Partial seizures with secondary generalisation | 7/13 | 47.1 | 390 | 4/7 members' labels |
| Atonic seizures | 7/13 | 36.0 | 477 | 1/7 members' labels |
| Focal dyscognitive seizures | 7/13 | 34.5 | 826 | 0/7 members' labels |
Member-specific signals (flagged in exactly one drug)
| Reaction | Drug | Reports | PRR | Label screen |
|---|---|---|---|---|
| Purple glove syndrome | Phenytoin | 65 | 981.4 | Not in label — unassessed |
| Magnetic resonance imaging head abnormal | Vigabatrin | 199 | 648.3 | Labeled (related wording) |
| Inspiratory capacity decreased | Phenytoin | 97 | 552.3 | Not in label — unassessed |
| Infantile spitting up | Vigabatrin | 79 | 259.7 | Likely indication confounding |
| Essential tremor | Primidone | 58 | 113.5 | Not in label — unassessed |
| Congenital nose malformation | Valproic Acid | 77 | 112.1 | Labeled (related wording) |
| Hyperammonaemia | Valproic Acid | 624 | 95.6 | Not in label — unassessed |
| Schizoaffective disorder | Valproic Acid | 180 | 74.7 | Not in label — unassessed |
| Hypocholesterolaemia | Lamotrigine | 88 | 64.0 | Not in label — unassessed |
| Gingival hypertrophy | Phenytoin | 85 | 60.6 | Not in label — unassessed |
| Skull malformation | Valproic Acid | 54 | 60.5 | Likely indication confounding |
| Psychiatric decompensation | Valproic Acid | 143 | 52.9 | Not in label — unassessed |
| Optic atrophy | Vigabatrin | 53 | 48.3 | Not in label — unassessed |
| Psychogenic seizure | Oxcarbazepine | 62 | 46.7 | Likely indication confounding |
| Oral mucosa erosion | Lamotrigine | 244 | 39.6 | Not in label — unassessed |
| Peripheral venous disease | Lamotrigine | 638 | 30.3 | Labeled (related wording) |
| Onychomadesis | Lamotrigine | 647 | 29.4 | Not in label — unassessed |
| Blepharospasm | Lamotrigine | 936 | 28.3 | Not in label — unassessed |
| Trigeminal neuralgia | Oxcarbazepine | 158 | 26.5 | Not in label — unassessed |
| Enanthema | Lamotrigine | 81 | 26.0 | Not in label — unassessed |
| Breast cancer stage iii | Lamotrigine | 810 | 22.9 | Not in label — unassessed |
| Rheumatic fever | Lamotrigine | 509 | 21.0 | Not in label — unassessed |
| Duodenal ulcer perforation | Lamotrigine | 824 | 20.1 | Labeled (related wording) |
| Live birth | Lamotrigine | 905 | 19.4 | Not in label — unassessed |
| Onychomycosis | Lamotrigine | 456 | 18.5 | Not in label — unassessed |
Common questions
Which anti-epileptic agent has the most FDA adverse event reports?
Lamotrigine has the most FAERS co-reports in this class (130,963), followed by Lamotrigine (75,488). Report volume tracks how widely and how long a drug has been used, and how much attention it has had, far more than its risk.
Which side effects are shared across anti-epileptic agent drugs?
Reaction terms flagged in at least half of the 13 members include status epilepticus, myoclonic epilepsy, sudden unexplained death in epilepsy, partial seizures with secondary generalisation, atonic seizures. A term shared across a class usually reflects the shared mechanism (or the shared patient population) rather than one product.
Does a FAERS signal mean the drug causes the reaction?
No. These are disproportionality signals from voluntary reports with no denominator. Each is screened against the FDA label (known vs unlabeled) on the drug pages; causality needs temporality, dose-response, plausibility and trial or cohort evidence.
Sources: openFDA FAERS pair statistics (OpenPV build 2026-09-14), FDA labels via openFDA, seriousness and death counts from openFDA count queries. Generated 2026-10-08. Not medical advice.