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Lacosamide Side Effects

In Summary

Commonly reported side effects of lacosamide include: dizziness, headache, tremor, fatigue, blurred vision, nausea, vomiting, nystagmus, diplopia, 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:

In addition to its needed effects, some unwanted effects may be caused by lacosamide. In the event that any of these side effects do occur, they may require medical attention.

Severity: Major

You should check with your doctor immediately if any of these side effects occur when taking lacosamide:

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 of the side effects that can occur with lacosamide may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

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. 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 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.

Not all side effects for lacosamide may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

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