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Vimpat Side Effects

Generic name: lacosamide

Medically reviewed by Last updated on May 18, 2024.

Note: This document contains side effect information about lacosamide. Some dosage forms listed on this page may not apply to the brand name Vimpat.

Applies to lacosamide: oral capsule extended release, oral solution, oral tablet. Other dosage forms:

Serious side effects of Vimpat

Along with its needed effects, lacosamide (the active ingredient contained in Vimpat) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking lacosamide:

More common

Less common

Incidence not known

Other side effects of Vimpat

Some side effects of lacosamide may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Less common

Incidence not known

For Healthcare Professionals

Applies to lacosamide: intravenous solution, oral capsule extended release, oral solution, oral tablet.


The most commonly reported adverse reactions have included diplopia, headache, dizziness, and nausea.

Nervous system

Very common (10% or more): Dizziness (up to 60%), headache (up to 13%), ataxia (up to 15%)

Common (1% to 10%): Somnolence, tremor, balance disorder, nystagmus, memory impairment, coordination abnormal, cognitive disorder, somnolence, tremor, dysarthria, disturbance in attention, paresthesia

Frequency not reported: Oral hypoesthesia, pyrexia

Postmarketing reports: Hypoesthesia, cerebellar syndrome, new or worsening seizures, dyskinesia[Ref]

Dizziness was reported in 25% of patients randomized to the recommended doses (200 to 400 mg/day) of this drug compared with 8% of placebo patients in studies in adult patients with partial-onset seizures taking 1 to 3 concomitant AEDs. It was the event most frequently leading to discontinuation (3%). Ataxia was reported by 6% of patients randomized to the recommended doses (200 to 400 mg/day) compared to 2% in placebo patients. Dizziness and ataxia were also observed in pediatric clinical trials.[Ref]


Very common (10% or more): Nausea (up to 24%), vomiting (up to 16%)

Common (1% to 10%): Diarrhea, constipation, flatulence, dyspepsia, dry mouth[Ref]


Very common (10% or more): Diplopia (up to 16%), blurred vision (up to 16%)[Ref]


Uncommon (0.1% to 1%): Hypersensitivity

Frequency not reported: Multiorgan hypersensitivity reactions (also known as Drug Reaction with Eosinophilia and Systemic Symptoms, or DRESS)[Ref]


Very common (10% or more): Fatigue (up to 15%)

Common (1% to 10%): Asthenia, vertigo, gait disturbance

Frequency not reported: Tinnitus, fall[Ref]


Common (1% to 10%): Injection site pain or discomfort

Uncommon (0.1% to 1%): Irritation, erythema[Ref]


Common (1% to 10%): Depression, confusional state, insomnia

Uncommon (0.1% to 1%): Aggression, agitation, euphoric mood, suicide attempt, suicidal ideation, hallucination

Frequency not reported: Irritability, feeling drunk

Postmarketing reports: Psychotic disorder[Ref]


Common (1% to 10%): Pruritus, rash

Uncommon (0.1% to 1%): Angioedema, urticaria

Frequency not reported: Neutropenia, anemia

Postmarketing reports: Stevens-Johnson syndrome, toxic epidermal necrolysis[Ref]


Very common (10% or more): Chest pain (up to 12%)

Common (1% to 10%): Syncope

Uncommon (0.1% to 1%): Atrioventricular block, bradycardia, atrial fibrillation, atrial flutter

Frequency not reported: Palpitations

Postmarketing reports: Cardiac arrhythmias including bradycardia, AV block, and ventricular tachyarrhythmia, which have rarely resulted in asystole, cardiac arrest, and death[Ref]

During clinical trials in adult patients with partial-onset seizures, asymptomatic first-degree atrioventricular (AV) block was observed in 0.4% (4/944) of patients randomized to this drug and 0% (0/364) of placebo patients. One case of profound bradycardia was observed in a patient during a 15-minute 150 mg IV infusion.

In short-term trials in adult patients with diabetic neuropathy, atrial fibrillation occurred in 0.5% of patients (placebo=0%). Syncope occurred in 1.2% of patients (placebo=0%).

A clinical pharmacology study in healthy subjects (n=247) did not shown any QTc interval prolongation or dose-related or clinically important effects on QRS duration. This drug did produce a dose-related increase in mean PR interval; the maximum mean PR interval increase corresponded with Tmax. The placebo-subtracted maximum increase in PR interval was 7.3 ms for the 400 mg/day group and 11.9 ms for the 800 mg/day group. In clinical trials, the placebo-subtracted mean maximum increase in PR interval for a 400 mg/day dose was 3.1 ms in patients with partial-onset seizures and 9.4 ms for patients with diabetic neuropathy.[Ref]


Common (1% to 10%): Muscle spasms

Frequency not reported: Connective tissue disorders[Ref]


Frequency not reported: Neutropenia, anemia

Postmarketing reports: Agranulocytosis[Ref]


Uncommon (0.1% to 1%): Liver function test abnormal

Frequency not reported: Hepatitis[Ref]


1. Cerner Multum, Inc. "UK Summary of Product Characteristics."

2. Cerner Multum, Inc. "Australian Product Information."

3. (2008) "Product Information. Vimpat (lacosamide)." UCB Pharma Inc

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.