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Vimpat Side Effects

Generic Name: lacosamide

Note: This page contains side effects data for the generic drug lacosamide. It is possible that some of the dosage forms included below may not apply to the brand name Vimpat.

In Summary

Common side effects of Vimpat include: vomiting, nystagmus, diplopia, dizziness, headache, tremor, fatigue, blurred vision, nausea, and ataxia. Other side effects include: memory impairment, abnormal gait, weakness, and vertigo. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to lacosamide: oral solution, oral tablet

Other dosage forms:

As well as its needed effects, lacosamide (the active ingredient contained in Vimpat) may cause unwanted side effects that require medical attention.

Severity: Major

If any of the following side effects occur while taking lacosamide, check with your doctor immediately:

More common:
  • Dizziness
  • false or unusual sense of well-being
  • shakiness and unsteady walk
  • sleepiness or unusual drowsiness
  • trembling or shaking of the hands or feet
  • unsteadiness, trembling, or other problems with muscle control or coordination
Less common:
  • Being forgetful
  • discouragement
  • feeling sad or empty
  • irritability
  • itching skin
  • lack of appetite
  • loss of balance control
  • loss of interest or pleasure
  • mood or mental changes
  • tearing of the skin
  • tiredness
  • trouble concentrating
  • trouble with sleeping
  • trouble with walking
Incidence not known:
  • Abnormal or decreased touch sensation
  • black, tarry stools
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • changes in patterns and rhythms of speech
  • chills
  • continuing ringing or buzzing or other unexplained noise in the ears
  • cough
  • fast, irregular, pounding, or racing heartbeat or pulse
  • feeling drunk
  • fever
  • hearing loss
  • lower back or side pain
  • painful or difficult urination
  • pale skin
  • shortness of breath
  • slurred speech
  • sore throat
  • trouble performing routine tasks
  • trouble with balance
  • trouble with speaking
  • troubled breathing with exertion
  • ulcers, sores, or white spots in the mouth
  • unusual bleeding or bruising
  • unusual tiredness or weakness

Severity: Minor

Some lacosamide side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common:
  • Blurred vision
  • double vision
  • headache
  • nausea
  • seeing double
  • vomiting
Less common:
  • Diarrhea
  • feeling of constant movement of self or surroundings
  • lack or loss of strength
  • sensation of spinning
  • uncontrolled eye movements
Incidence not known:
  • Acid or sour stomach
  • belching
  • difficulty having a bowel movement (stool)
  • dry mouth
  • heartburn
  • indigestion
  • muscle spasms
  • stomach discomfort, upset, or pain

For Healthcare Professionals

Applies to lacosamide: intravenous solution, oral solution, oral tablet

Nervous system

Nervous system side effects including dizziness (31%), headache (13%), ataxia (8%), somnolence (7%), tremor (7%), nystagmus (5%), balance disorder (4%), memory impairment (2%), paresthesia, cognitive disorder, hypoesthesia, dysarthria, disturbance in attention, and cerebellar syndrome have been reported.[Ref]


Gastrointestinal side effects including vomiting (9%), diarrhea (4%), nausea (1%), constipation, dyspepsia, dry mouth, and oral hypoesthesia have been reported.[Ref]


Ocular side effects including diplopia (11%) and blurred vision (8%) have been reported.[Ref]


General side effects including fatigue (9%), gait disturbance (2%), asthenia (2%), irritability, pyrexia, and feeling drunk have been reported.[Ref]


Other side effects including vertigo (4%), contusion (3%), skin laceration (3%), fall, and tinnitus have been reported.[Ref]


Local side effects following intravenous administration included injection site pain or discomfort (2.5%), irritation (1%), and erythema (0.5%).


Psychiatric side effects including depression (2%), confusional state, hallucination, and altered mood have been reported.[Ref]


Dermatologic side effects including pruritus (2%) and rash have been reported.[Ref]


Cardiovascular side effects including palpitations have been reported.

One case of profound bradycardia (26 beats per minute: BP 100/60 mmHg) was observed in a patient during a 15 minute infusion of lacosamide (the active ingredient contained in Vimpat) This patient was also on a beta-blocker. Infusion was discontinued and the patient experienced a rapid recovery.


Musculoskeletal side effects including muscle spasms have been reported.


Hematologic side effects including neutropenia and anemia have been reported. Agranulocytosis has been reported postmarketing.


Abnormalities in liver function tests have been observed in controlled trials with lacosamide (the active ingredient contained in Vimpat) in adult patients with partial-onset seizures who were taking 1 to 3 concomitant antiepileptic drugs. Elevations of ALT to greater than or equal to 3 times the ULN occurred in 0.7% of lacosamide patients and 0% of placebo patients. One case of hepatitis with transaminases greater than 20 times the ULN was observed in one healthy subject 10 days after lacosamide treatment completion, along with nephritis (proteinuria and urine casts).

Hepatic side effects including abnormalities in liver function tests have been reported.


1. "Product Information. Vimpat (lacosamide)." UCB Pharma Inc, Smyrna, GA.

It is possible that some side effects of Vimpat may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

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