What the label lists and what reports show
Cenobamate side effects
Cenobamate's FDA label: “The most common adverse reactions in patients receiving XCOPRI (at least 10% for XCOPRI and more frequently than placebo) include somnolence, dizziness, fatigue, diplopia, and headache.” FAERS holds 8,296 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 fatigue (831 reports).
- No generic listed
- DEA Schedule V
Check it at the source: the cenobamate FDA label on DailyMed (effective August 25, 2025, SK Life Science, 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 XCOPRI?XCOPRI may cause serious side effects, including: See “What is the most important information I should know about XCOPRI?” liver problems. XCOPRI may cause liver problems. Your healthcare provider will do blood tests to check your liver before you start XCOPRI if a blood test has not been done within the prior 3 months and while you take XCOPRI if needed. Tell your healthcare provider right away if you develop any symptoms of liver problems, such as: yellowing of the skin and eyes (jaundice) nausea vomiting unusual darkening of the urine feeling tired or weak nervous system problems. XCOPRI may cause problems that can affect your nervous system. […]
Source: FDA drug label, SK Life Science, Inc., effective August 25, 2025 (SPL set 565c2126-57ae-4e29-b443-723bbe7e2072), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions in patients receiving XCOPRI (at least 10% for XCOPRI and more frequently than placebo) include somnolence, dizziness, fatigue, diplopia, and headache.
Table 4: Adverse Reactions in Pooled Placebo-Controlled Adjunctive Therapy Studies in Patients with Partial-Onset Seizures with XCOPRI Frequency in Any Treatment Arm Greater Than 1% Over Placebo
| Reaction | n = 108 % | n= 223 % | n=111 % | n=216 % |
|---|---|---|---|---|
| Palpitations | 0 | 0 | 2 | 0 |
| Vertigo | 1 | 1 | 6 | 1 |
| Diplopia | 6 | 7 | 15 | 2 |
| Vision Blurred | 2 | 2 | 4 | 0 |
| Nausea | 6 | 6 | 9 | 3 |
| Constipation | 2 | 4 | 8 | 0 |
| Diarrhea | 1 | 3 | 5 | 0 |
| Vomiting | 2 | 4 | 5 | 0 |
| Dry Mouth | 1 | 1 | 3 | 0 |
| Abdominal Pain | 2 | 2 | 1 | 0 |
| Dyspepsia | 2 | 2 | 0 | 0 |
| Nasopharyngitis | 2 | 4 | 5 | 3 |
| Pharyngitis | 1 | 2 | 0 | 0 |
| Urinary Tract Infection | 2 | 5 | 0 | 2 |
| Head Injury | 1 | 0 | 2 | 0 |
| Alanine Aminotransferase Increased | 1 | 1 | 4 | 0 |
| Aspartate Aminotransferase Increased | 1 | 1 | 3 | 0 |
| Weight Decreased | 2 | 0 | 1 | 0 |
| Decreased Appetite | 3 | 1 | 5 | 1 |
| Back Pain | 4 | 2 | 5 | 3 |
| Musculoskeletal Chest Pain | 2 | 1 | 0 | 0 |
| Somnolence | 19 | 22 | 37 | 11 |
| Dizziness | 18 | 22 | 33 | 15 |
| Fatigue | 12 | 14 | 24 | 7 |
| Headache | 10 | 12 | 10 | 9 |
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 in more detail in the Warnings and Precautions section of the labeling: Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity [see Warnings and Precautions ( 5.1 )] QT Shortening [see Warnings and Precautions ( 5.2 )] Suicidal Behavior and Ideation [see Warnings and Precautions ( 5.3 )] Liver Injury [see Warnings and Precautions ( 5.4 )] Neurological Adverse Reactions [see Warnings and Precautions ( 5.5 )] Withdrawal of Antiepileptic Drugs [see Warnings and Precautions ( 5.6 )] The most common adverse reactions in patients receiving XCOPRI (at least 10% for XCOPRI and more frequently than placebo) include somnolence, dizziness, fatigue, diplopia, and headache. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact SK Life Science, Inc. at 1-866-657-5574 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 and for varying durations, adverse reaction frequencies observed in the clinical trials of a drug cannot be directly compared with frequencies in the clinical trials of another drug and may not reflect the frequencies observed in practice. …
Source: FDA drug label, SK Life Science, Inc., effective August 25, 2025 (SPL set 565c2126-57ae-4e29-b443-723bbe7e2072), via openFDA; the full label on DailyMed
What do FAERS reports show?
8,296 reports list cenobamate among the medicines taken, each a report of something that happened, not proof the medicine caused it; 197 are coded as a death and 1,666 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. Reports rose sharply in 2025 (2,052, against a median of 83 a year): FAERS counts follow reporting, which news, litigation and label changes can drive, not how often a reaction happens. Of the 17 reactions below, 14 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?
- Cenobamate: 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