What the label lists and what reports show
Rufinamide side effects
Rufinamide's FDA label: “Most common adverse reactions (≥ 10% and greater than placebo) were headache, dizziness, fatigue, somnolence, and nausea ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Eisai Inc.” FAERS holds 2,575 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is somnolence (181 reports).
- Generic listed
Check it at the source: the rufinamide FDA label on DailyMed (effective December 15, 2022, Eisai Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of BANZEL?See “What is the most important information I should know about BANZEL?” BANZEL may cause serious side effects including: BANZEL can also cause allergic reactions or serious problems which may affect organs and other parts of your body like the liver or blood cells. You may or may not have a rash with these types of reactions. Call your healthcare provider right away if you have any of the following. Symptoms may include: swelling of your face, eyes, lips, or tongue trouble swallowing or breathing a skin rash hives fever, swollen glands, or sore throat that do not go away or come and go swollen glands yellowing of your skin or eyes dark urine unusual bruising or bleeding severe fatigue or weakness severe muscle pain your seizures happen more often or become worse Call your healthcare provider right away if you have any of the symptoms listed above. […]
Source: FDA drug label, Eisai Inc., effective December 15, 2022 (SPL set 0a3fa925-1abd-458a-bd57-4ae780a1ef2d), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions (≥ 10% and greater than placebo) were headache, dizziness, fatigue, somnolence, and nausea ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Eisai Inc.
Table 2: Adverse Reactions in Pediatric Patients (Ages 3 to less than 17 years) in Pooled Double-Blind Adjunctive Trials
| Adverse Reaction | BANZEL (N=187) % | Placebo (N=182) % |
|---|---|---|
| Somnolence | 17 | 9 |
| Vomiting | 17 | 7 |
| Headache | 16 | 8 |
| Fatigue | 9 | 8 |
| Dizziness | 8 | 6 |
| Nausea | 7 | 3 |
| Influenza | 5 | 4 |
| Nasopharyngitis | 5 | 3 |
| Decreased Appetite | 5 | 2 |
| Rash | 4 | 2 |
| Ataxia | 4 | 1 |
| Diplopia | 4 | 1 |
| Bronchitis | 3 | 2 |
| Sinusitis | 3 | 2 |
| Psychomotor Hyperactivity | 3 | 1 |
| Upper Abdominal Pain | 3 | 2 |
| Aggression | 3 | 2 |
| Ear Infection | 3 | 1 |
| Disturbance in Attention | 3 | 1 |
| Pruritis | 3 | 0 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following serious adverse reactions are described below and elsewhere in the labeling: Suicidal Behavior and Ideation [see Warnings and Precautions ( 5.1 )] Central Nervous System Reactions [see Warnings and Precautions ( 5.2 )] QT Shortening [see Warnings and Precautions ( 5.3 )] Multi-Organ Hypersensitivity/Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) [see Warnings and Precautions ( 5.4 )] Leukopenia [see Warnings and Precautions ( 5.7 )] Most common adverse reactions (≥ 10% and greater than placebo) were headache, dizziness, fatigue, somnolence, and nausea ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Eisai Inc. at 1-888-274-2378 or www.banzel.com or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. …
Source: FDA drug label, Eisai Inc., effective December 15, 2022 (SPL set 0a3fa925-1abd-458a-bd57-4ae780a1ef2d), via openFDA; the full label on DailyMed
What do FAERS reports show?
2,575 reports list rufinamide among the medicines taken, each a report of something that happened, not proof the medicine caused it; 151 are coded as a death and 714 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 16 reactions below, 9 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Rufinamide: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions