Perampanel side effects: what 7,529 FDA adverse event reports show
Drug class
Noncompetitive AMPA Glutamate Receptor Antagonist
Who reports
7,529 reports · 83% serious · 466 with death outcome · 54% female
Used for
Perampanel tablets, a non-competitive AMPA glutamate receptor antagonist, is indicated for: Treatment of partial-onset seizures with or without secondarily generalized seizures in patients with epilepsy 4 years of age and older ( 1.1 ) Adjunctive thera.
What it is
Perampanel tablets contain perampanel a non-competitive AMPA receptor antagonist as a 4:3 hydrate.
Boxed warning
SERIOUS PSYCHIATRIC AND BEHAVIORAL REACTIONS WARNING: SERIOUS PSYCHIATRIC AND BEHAVIORAL REACTIONS Serious or life-threatening psychiatric and behavioral adverse reactions including aggression, hostility, irritability, anger, and homicidal ideation and threats have been reported in patients taking perampanel ( 5.1).
Causality screen of the 40 strongest signals
What the badges mean
- Labeled — boxed warning The term (or its clinical synonym) appears in the FDA boxed warning: causality is regulator-recognised and considered serious.
- Labeled adverse reaction The exact term appears in the label's warnings or adverse-reactions sections: a known, expected effect. The FAERS signal confirms the label rather than discovering anything.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only and flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 215 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Status epilepticus | 345 | 87.5 78.8–97.2ROR 91.7 · χ² 28,536 / p <1e-300 | 84.5 EB05 77.3 · IC025 +6.1 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 58.9 · 93% clinician | no trial data cached |
| Epilepsy | 361 | 33.3 30.1–36.9ROR 34.9 · χ² 11,166 / p <1e-300 | 32.9 EB05 30.1 · IC025 +4.8 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 22.9 | no trial data cached |
| Generalised tonic-clonic seizure | 178 | 30.6 26.5–35.4ROR 31.3 · χ² 5,017 / p <1e-300 | 30.2 EB05 26.7 · IC025 +4.6 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 20.5 | no trial data cached |
| Aggression | 499 | 28.0 25.7–30.5ROR 29.9 · χ² 12,849 / p <1e-300 | 27.7 EB05 25.7 · IC025 +4.6 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 21.1 | no trial data cached |
| Seizure | 1,138 | 27.9 26.4–29.4ROR 32.7 · χ² 29,325 / p <1e-300 | 27.6 EB05 26.3 · IC025 +4.7 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 18.3 | no trial data cached |
| Ataxia | 95 | 22.4 18.3–27.3ROR 22.6 · χ² 1,903 / p <1e-300 | 22.1 EB05 18.6 · IC025 +4.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 14.2 · 92% clinician | no trial data cached |
| Drug resistance | 126 | 13.7 11.5–16.3ROR 13.9 · χ² 1,468 / p <1e-300 | 13.6 EB05 11.7 · IC025 +3.4 3/3 methods agree | Reporting / coding artifact | serious PRR 10.4 · ♀ 77% (drug 54%) · 98% clinician | no trial data cached |
| Psychotic disorder | 137 | 13.0 11.0–15.3ROR 13.2 · χ² 1,496 / p <1e-300 | 12.8 EB05 11.1 · IC025 +3.3 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 9.7 | no trial data cached |
| Altered state of consciousness | 90 | 11.7 9.5–14.3ROR 11.8 · χ² 865 / p 2e-190 | 11.5 EB05 9.6 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 8.1 · 97% clinician | no trial data cached |
| Pneumonia aspiration | 103 | 11.5 9.5–14.0ROR 11.7 · χ² 979 / p 3e-215 | 11.4 EB05 9.6 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious PRR 8.0 · ♀ 20% (drug 54%) | no trial data cached |
| Anger | 139 | 11.4 9.7–13.5ROR 11.6 · χ² 1,310 / p 4e-287 | 11.3 EB05 9.8 · IC025 +3.2 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 9.6 | no trial data cached |
| Irritability | 245 | 11.4 10.0–12.9ROR 11.7 · χ² 2,303 / p <1e-300 | 11.3 EB05 10.1 · IC025 +3.3 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 10.4 | no trial data cached |
| Drug level decreased | 39 | 10.7 7.8–14.6ROR 10.7 · χ² 330 / p 4e-74 | 10.1 EB05 7.6 · IC025 +2.7 3/3 methods agree | Reporting / coding artifact | serious PRR 6.8 · 95% clinician | no trial data cached |
| Suicide attempt | 207 | 9.5 8.3–10.9ROR 9.8 · χ² 1,568 / p <1e-300 | 9.4 EB05 8.3 · IC025 +3.0 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 6.6 · 95% clinician | no trial data cached |
| Hallucination, auditory | 50 | 8.8 6.7–11.6ROR 8.8 · χ² 336 / p 3e-75 | 8.3 EB05 6.5 · IC025 +2.6 3/3 methods agree | Not in label — unassessed | serious PRR 6.9 | no trial data cached |
| Personality change | 28 | 8.4 5.8–12.1ROR 8.4 · χ² 174 / p 6e-40 | 7.6 EB05 5.4 · IC025 +2.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.1 | no trial data cached |
| Myoclonus | 35 | 8.2 5.9–11.4ROR 8.2 · χ² 213 / p 1e-48 | 7.6 EB05 5.6 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 5.8 · 97% clinician | no trial data cached |
| Prescribed underdose | 58 | 8.1 6.3–10.5ROR 8.2 · χ² 354 / p 3e-79 | 7.7 EB05 6.2 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 8.1 · 93% clinician | no trial data cached |
| Prescribed overdose | 56 | 8.1 6.2–10.5ROR 8.1 · χ² 339 / p 4e-76 | 7.7 EB05 6.1 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 7.7 | no trial data cached |
| Abnormal behaviour | 115 | 8.0 6.7–9.7ROR 8.2 · χ² 702 / p 5e-155 | 7.8 EB05 6.7 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 5.9 | no trial data cached |
| Cognitive disorder | 123 | 7.4 6.2–8.8ROR 7.5 · χ² 671 / p 2e-148 | 7.2 EB05 6.2 · IC025 +2.5 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 | no trial data cached |
| Dysarthria (slurred speech) | 97 | 7.2 5.9–8.8ROR 7.3 · χ² 511 / p 2e-113 | 7.0 EB05 5.9 · IC025 +2.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.3 | no trial data cached |
| Somnolence (drowsiness) | 513 | 7.1 6.5–7.7ROR 7.6 · χ² 2,711 / p <1e-300 | 7.1 EB05 6.6 · IC025 +2.7 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 7.0 | no trial data cached |
| Intentional overdose | 161 | 7.0 6.0–8.2ROR 7.2 · χ² 830 / p 1e-182 | 6.9 EB05 6.1 · IC025 +2.5 3/3 methods agree | Reporting / coding artifact | serious PRR 5.0 · 94% clinician | no trial data cached |
| Psychomotor hyperactivity | 40 | 6.7 4.9–9.1ROR 6.7 · χ² 188 / p 5e-43 | 6.3 EB05 4.8 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 7.1 | no trial data cached |
| Drug level increased | 39 | 6.6 4.8–9.0ROR 6.6 · χ² 178 / p 6e-41 | 6.1 EB05 4.7 · IC025 +2.1 3/3 methods agree | Reporting / coding artifact | serious PRR 4.6 · 92% clinician | no trial data cached |
| Encephalopathy | 57 | 6.5 5.0–8.4ROR 6.5 · χ² 259 / p 1e-58 | 6.2 EB05 4.9 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 · 98% clinician | no trial data cached |
| Salivary hypersecretion | 23 | 6.4 4.3–9.7ROR 6.4 · χ² 100 / p 9e-24 | 5.7 EB05 4.0 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 6.0 · ♀ 33% (drug 54%) | no trial data cached |
| Hypotonia | 23 | 6.4 4.3–9.6ROR 6.4 · χ² 99 / p 1e-23 | 5.7 EB05 4.0 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 4.4 | no trial data cached |
| Agitation | 166 | 6.3 5.4–7.3ROR 6.4 · χ² 734 / p 7e-162 | 6.2 EB05 5.4 · IC025 +2.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.6 | no trial data cached |
| Rebound effect | 25 | 6.1 4.2–9.1ROR 6.2 · χ² 102 / p 2e-24 | 5.6 EB05 4.0 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 · ♀ 100% (drug 54%) · 100% clinician | no trial data cached |
| Suicidal ideation (thoughts of suicide) | 202 | 6.1 5.4–7.0ROR 6.3 · χ² 867 / p 6e-191 | 6.1 EB05 5.4 · IC025 +2.4 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 3.8 | no trial data cached |
| Mydriasis | 28 | 6.1 4.2–8.8ROR 6.1 · χ² 114 / p 7e-27 | 5.6 EB05 4.0 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 5.3 | no trial data cached |
| Affect lability | 21 | 6.1 3.9–9.3ROR 6.1 · χ² 84 / p 3e-20 | 5.4 EB05 3.7 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.0 | no trial data cached |
| Drug reaction with eosinophilia and systemic symptoms | 55 | 6.0 4.6–7.8ROR 6.0 · χ² 224 / p 6e-51 | 5.7 EB05 4.6 · IC025 +2.1 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 4.2 · 96% clinician | no trial data cached |
| Drug interaction | 340 | 6.0 5.4–6.6ROR 6.2 · χ² 1,412 / p <1e-300 | 5.9 EB05 5.4 · IC025 +2.4 3/3 methods agree | Reporting / coding artifact | serious PRR 4.2 · 95% clinician | no trial data cached |
| Delusion | 33 | 5.9 4.2–8.4ROR 6.0 · χ² 131 / p 2e-30 | 5.5 EB05 4.1 · IC025 +1.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.8 | no trial data cached |
| Hallucination, visual | 44 | 5.8 4.4–7.9ROR 5.9 · χ² 172 / p 1e-39 | 5.5 EB05 4.3 · IC025 +2.0 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 | no trial data cached |
| Sedation | 54 | 5.8 4.4–7.5ROR 5.8 · χ² 208 / p 2e-47 | 5.5 EB05 4.4 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.6 | no trial data cached |
| Mood altered | 55 | 5.6 4.3–7.3ROR 5.7 · χ² 205 / p 7e-47 | 5.4 EB05 4.3 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.4 · ♀ 83% (drug 54%) | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Seizure | 1,138 | 27.9 26.4–29.4ROR 32.7 · χ² 29,325 / p <1e-300 | 27.6 EB05 26.3 · IC025 +4.7 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 18.3 | no trial data cached |
| Drug ineffective (drug did not work) | 1,096 | 2.3 2.2–2.4ROR 2.5 · χ² 875 / p 1e-192 | 2.3 EB05 2.2 · IC025 +1.1 3/3 methods agree | Reporting / coding artifact | serious PRR 4.2 · 90% clinician | no trial data cached |
| Off label use (used outside approved label) | 806 | 2.6 2.4–2.8ROR 2.8 · χ² 816 / p 8e-180 | 2.6 EB05 2.4 · IC025 +1.3 3/3 methods agree | Reporting / coding artifact | serious PRR 2.8 | no trial data cached |
| Somnolence (drowsiness) | 513 | 7.1 6.5–7.7ROR 7.6 · χ² 2,711 / p <1e-300 | 7.1 EB05 6.6 · IC025 +2.7 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 7.0 | no trial data cached |
| Aggression | 499 | 28.0 25.7–30.5ROR 29.9 · χ² 12,849 / p <1e-300 | 27.7 EB05 25.7 · IC025 +4.6 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 21.1 | no trial data cached |
| Dizziness | 396 | 2.2 2.0–2.4ROR 2.3 · χ² 269 / p 9e-61 | 2.2 EB05 2.0 · IC025 +1.0 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 2.0 | no trial data cached |
| Epilepsy | 361 | 33.3 30.1–36.9ROR 34.9 · χ² 11,166 / p <1e-300 | 32.9 EB05 30.1 · IC025 +4.8 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 22.9 | no trial data cached |
| Status epilepticus | 345 | 87.5 78.8–97.2ROR 91.7 · χ² 28,536 / p <1e-300 | 84.5 EB05 77.3 · IC025 +6.1 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 58.9 · 93% clinician | no trial data cached |
| Drug interaction | 340 | 6.0 5.4–6.6ROR 6.2 · χ² 1,412 / p <1e-300 | 5.9 EB05 5.4 · IC025 +2.4 3/3 methods agree | Reporting / coding artifact | serious PRR 4.2 · 95% clinician | no trial data cached |
| Irritability | 245 | 11.4 10.0–12.9ROR 11.7 · χ² 2,303 / p <1e-300 | 11.3 EB05 10.1 · IC025 +3.3 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 10.4 | no trial data cached |
| Condition aggravated | 240 | 2.2 2.0–2.5ROR 2.3 · χ² 161 / p 4e-37 | 2.2 EB05 2.0 · IC025 +0.9 | Reporting / coding artifact | serious PRR 2.1 | no trial data cached |
| Fall | 223 | 1.9 1.6–2.1ROR 1.9 · χ² 90 / p 9e-22 | 1.9 EB05 1.7 · IC025 +0.7 | Labeled — boxed warning exact term | serious PRR 1.4 | no trial data cached |
| Product use in unapproved indication | 219 | 2.5 2.2–2.8ROR 2.5 · χ² 197 / p 4e-45 | 2.5 EB05 2.2 · IC025 +1.1 3/3 methods agree | Reporting / coding artifact | serious PRR 3.2 | no trial data cached |
| Gait disturbance | 207 | 3.0 2.6–3.4ROR 3.1 · χ² 277 / p 2e-62 | 3.0 EB05 2.7 · IC025 +1.3 3/3 methods agree | Labeled — boxed warning exact term | serious PRR 2.6 | no trial data cached |
| Suicide attempt | 207 | 9.5 8.3–10.9ROR 9.8 · χ² 1,568 / p <1e-300 | 9.4 EB05 8.3 · IC025 +3.0 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 6.6 · 95% clinician | no trial data cached |
Unlabeled candidate signals
These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.
- Altered state of consciousness — n=90, PRR 11.7
- Pneumonia aspiration — n=103, PRR 11.5
- Hallucination, auditory — n=50, PRR 8.8
- Myoclonus — n=35, PRR 8.2
- Prescribed underdose — n=58, PRR 8.1
- Prescribed overdose — n=56, PRR 8.1
- Abnormal behaviour — n=115, PRR 8.0
- Cognitive disorder — n=123, PRR 7.4
- Psychomotor hyperactivity — n=40, PRR 6.7
- Encephalopathy — n=57, PRR 6.5
✓ A hand-written Bradford Hill causality assessment exists for this drug: Perampanel ↔ Aggression.
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Perampanel?
In FDA FAERS, the most frequently co-reported reaction terms for Perampanel are seizure, somnolence, aggression, dizziness, epilepsy, status epilepticus. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Perampanel have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: SERIOUS PSYCHIATRIC AND BEHAVIORAL REACTIONS WARNING: SERIOUS PSYCHIATRIC AND BEHAVIORAL REACTIONS Serious or life-threatening psychiatric and behavioral adverse reactions including aggression, hostility, irritability, anger, and homicidal ideation and threats have been reported in patients taking perampanel ( 5.1).
Do FAERS signals prove that Perampanel causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID 1b0458ea-e718-4d48-ae55-ad9b4d863810, effective 20251219; matched on
openfda.generic_name.exact:"PERAMPANEL") - Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 255 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath
Page generated 2026-10-08. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.