What the label lists and what reports show
Lacosamide side effects
Lacosamide's FDA label: “Most common adverse reactions in adults (≥10% and greater than placebo) are diplopia, headache, dizziness, nausea, and somnolence ( 6.1 ) Monotherapy: Most common adverse reactions are similar to those seen in adjunctive therapy studies ( 6.1 ) Pediatric …” FAERS holds 36,995 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 dizziness (1,669 reports).
- Generic listed
- DEA Schedule V
Check it at the source: the lacosamide FDA label on DailyMed (effective May 12, 2026, UCB, 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 VIMPAT?See " What is the most important information I should know about VIMPAT? " VIMPAT may cause other serious side effects including: A serious allergic reaction that may affect your skin or other parts of your body such as your liver or blood cells. Call your healthcare provider right away if you have: a skin rash, hives fever or swollen glands that do not go away shortness of breath tiredness (fatigue) swelling of the legs yellowing of the skin or whites of the eyes dark urine The most common side effects of VIMPAT include: double vision headache dizziness nausea sleepiness These are not all of the possible side effects of VIMPAT. For more information ask your healthcare provider or pharmacist. Tell your healthcare provider about any side effect that bothers you or that does not go away. Call your doctor for medical advice about side effects. […]
Source: FDA drug label, NDA022254 (Ucb Inc), as published by UCB, Inc., effective May 12, 2026 (SPL set 9e79b42c-38a3-4b2c-a196-a5a1948250e2), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions in adults (≥10% and greater than placebo) are diplopia, headache, dizziness, nausea, and somnolence ( 6.1 ) Monotherapy: Most common adverse reactions are similar to those seen in adjunctive therapy studies ( 6.1 ) Pediatric patients: Adverse reactions are similar to those seen in adult patients ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact UCB, Inc.
Table 4: Adverse Reactions Incidence in Adjunctive Therapy Pooled, Placebo-Controlled Trials in Adult Patients with Partial-Onset Seizures (Studies 2, 3, and 4)
| Adverse Reaction | Placebo N=364 % | VIMPAT 200 mg/day N=270 % | VIMPAT 400 mg/day N=471 % | VIMPAT 600 mg/day 600 mg dose is 1.5 times greater than the maximum recommended dose.… | VIMPAT Total N=944 % |
|---|---|---|---|---|---|
| Vertigo | 1 | 5 | 3 | 4 | 4 |
| Diplopia | 2 | 6 | 10 | 16 | 11 |
| Blurred Vision | 3 | 2 | 9 | 16 | 8 |
| Nausea | 4 | 7 | 11 | 17 | 11 |
| Vomiting | 3 | 6 | 9 | 16 | 9 |
| Diarrhea | 3 | 3 | 5 | 4 | 4 |
| Fatigue | 6 | 7 | 7 | 15 | 9 |
| Gait disturbance | <1 | <1 | 2 | 4 | 2 |
| Asthenia | 1 | 2 | 2 | 4 | 2 |
| Contusion | 3 | 3 | 4 | 2 | 3 |
| Skin laceration | 2 | 2 | 3 | 3 | 3 |
| Dizziness | 8 | 16 | 30 | 53 | 31 |
| Headache | 9 | 11 | 14 | 12 | 13 |
| Ataxia | 2 | 4 | 7 | 15 | 8 |
| Somnolence | 5 | 5 | 8 | 8 | 7 |
| Tremor | 4 | 4 | 6 | 12 | 7 |
| Nystagmus | 4 | 2 | 5 | 10 | 5 |
| Balance disorder | 0 | 1 | 5 | 6 | 4 |
| Memory impairment | 2 | 1 | 2 | 6 | 2 |
| Depression | 1 | 2 | 2 | 2 | 2 |
| Pruritus | 1 | 3 | 2 | 3 | 2 |
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) ] Dizziness and Ataxia [see Warnings and Precautions (5.2) ] Cardiac Rhythm and Conduction Abnormalities [see Warnings and Precautions (5.3) ] Syncope [see Warnings and Precautions (5.4) ] Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity Reactions [see Warnings and Precautions (5.6) ] Adjunctive therapy: Most common adverse reactions in adults (≥10% and greater than placebo) are diplopia, headache, dizziness, nausea, and somnolence ( 6.1 ) Monotherapy: Most common adverse reactions are similar to those seen in adjunctive therapy studies ( 6.1 ) Pediatric patients: Adverse reactions are similar to those seen in adult patients ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact UCB, Inc. at 1-844-599-2273 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, NDA022254 (Ucb Inc), as published by UCB, Inc., effective May 12, 2026 (SPL set 9e79b42c-38a3-4b2c-a196-a5a1948250e2), via openFDA; the full label on DailyMed
What do FAERS reports show?
36,995 reports list lacosamide among the medicines taken, each a report of something that happened, not proof the medicine caused it; 3,133 are coded as a death and 12,683 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 15 reactions below, 10 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?
- Lacosamide: 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