Commonly reported side effects of lamotrigine include: ataxia, skin rash, headache, insomnia, and nausea. Other side effects include: infection, dyspepsia, abnormal gait, constipation, and drowsiness. See below for a comprehensive list of adverse effects.

Applies to lamotrigine: oral tablet, oral tablet chewable, oral tablet disintegrating, oral tablet extended release

Along with its needed effects, lamotrigine 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 lamotrigine:

More common

• Blurred vision
• changes in vision
• clumsiness or unsteadiness
• double vision
• poor coordination
• skin rash

Less common

• Anxiety
• chest pain
• confusion
• continuous, uncontrolled back and forth or rolling eye movements
• depression
• constipation
• increase in seizures
• infection
• irritability

Rare

• Blistering, peeling, or loosening of the skin
• chills
• cough
• dark urine
• diarrhea
• fever
• general feeling of discomfort or illness
• headache
• itching
• joint pain
• loss of appetite
• memory loss
• muscle cramps, pain, or weakness
• nausea
• red or irritated eyes
• runny nose
• shivering
• small red or purple spots on the skin
• sore throat
• sores, ulcers, or white spots on the lips or in the mouth
• swelling of the face, mouth, hands, or feet
• swollen lymph nodes
• trouble sleeping
• trouble with breathing
• unusual bleeding or bruising
• unusual tiredness or weakness
• vomiting
• yellow eyes or skin

Incidence not known

• Back, leg, or stomach pains
• bleeding gums
• bloating
• blood in the urine
• bloody, black or tarry stools
• bluish lips or skin
• bruising
• cough
• coughing or vomiting blood
• difficulty with breathing
• difficulty with swallowing
• fainting
• fast heartbeat
• general body swelling
• general feeling of tiredness or weakness
• heartburn
• high fever
• hoarseness
• lightheadedness
• loss of balance control
• lower back or side pain
• mask-like face
• muscle spasms
• nosebleeds
• not breathing
• pain or burning in the throat
• painful or difficult urination
• pains in the stomach, side, or abdomen, possibly radiating to the back
• pale skin
• persistent bleeding or oozing from puncture sites, mouth, or nose
• rapid, shallow breathing
• redness, soreness, or itching skin
• shuffling walk
• slowed movement
• slurred speech
• sores, welting, or blisters
• stiffness of the arms and legs
• swollen or painful glands
• tic-like (jerky) movements
• tightness in the chest
• unexplained bleeding or bruising

Get emergency help immediately if any of the following symptoms of overdose occur while taking lamotrigine:

Symptoms of overdose

• Clumsiness or unsteadiness (severe)
• continuous, uncontrolled back and forth or rolling eye movements (severe)
• dizziness (severe)
• drowsiness (severe)
• dryness of the mouth (severe)
• headache (severe)
• increased heart rate
• loss of consciousness
• slurred speech (severe)

Some side effects of lamotrigine 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

• Dizziness
• drowsiness

Less common

• Indigestion
• loss of strength
• menstrual pain
• pain
• trembling or shaking
• trouble with sleeping
• unusual weight loss

Applies to lamotrigine: oral tablet, oral tablet disintegrating, oral tablet dispersible, oral tablet extended release

The more commonly reported adverse reactions have included dizziness, headache, diplopia, ataxia, nausea, blurred vision, somnolence, and rash.

Postmarketing reports: Progressive immunosuppression, Lupus-like reaction, vasculitis, drug reaction with eosinophilia and systemic symptoms (DRESS), hemophagocytic lymphohistiocytosis (HLH)

In cases of hemophagocytic lymphohistiocytosis (HLH), patients have presented with signs of systemic inflammation (fever, rash, hepatosplenomegaly, and organ system dysfunction) and blood dyscrasias. Symptoms have been reported within 8 to 24 days.

Uncommon (0.1% to 1%): Allergic reaction, chills, malaise

Very common (10% or more): Dizziness (38%), headache (29%), ataxia (22%), somnolence (14%)

Common (1% to 10%): Seizure exacerbation, incoordination, insomnia, tremor, speech disorder, amnesia, hypoesthesia, pain, gait abnormality, vertigo, dyspraxia, confusion, paresthesia

Uncommon (0.1% to 1%): Akathisia, aphasia, central nervous system depression, dysarthria, dyskinesia, hyperkinesia, hypertonia, movement disorder, myoclonus, sudden unexplained death in Epilepsy (SUDEP)

Rare (less than 0.1%): Choreoathetosis, dystonia, extrapyramidal syndrome, faintness, grand mal seizures, hemiplegia, hyperalgesia, hyperesthesia, hypokinesia, hypotonia, neuralgia, muscle spasm, neuralgia, paralysis, peripheral neuritis

Very rare (less than 0.01%): Muscle spasm, paralysis, peripheral neuritis

Postmarketing reports: Exacerbation of Parkinsonian symptoms in patients with pre-existing Parkinson's disease, tics

Sudden unexplained death in epilepsy (SUDEP) was reported in 20 of 4700 patients with epilepsy during premarketing development. While this exceeds the expected rate in healthy populations, it is within the range for patients with epilepsy.

Common (1% to 10%): Depression, anxiety, irritability, disturbance of concentration, emotional lability, abnormal thinking, nervousness

Uncommon (0.1% to 1%): Apathy, euphoria, hallucinations, hostility, depersonalization, memory decrease, mind racing, panic attack, paranoid reaction, personality disorder, psychosis, sleep disorder, stupor, suicidal ideation

Rare (less than 0.1%): Delirium, delusions, dysphoria, manic depression reaction, neurosis

Postmarketing reports: Aggression, nightmares

Antiepileptic drugs (AEDs) increase the risk of suicidal thoughts or behavior. Pooled analyses of 199 placebo-controlled clinical trials of 11 different AEDs (monotherapy or adjunctive therapy) showed twice the risk compared with placebo patients; an estimated incidence of 0.43% (n=27,863) in AED-treated patients compared to 0.24% (n=16,029) in placebo. The median treatment duration was 12 weeks. There were 4 suicides in AED-treated patients (placebo=0). The risk of suicidal thoughts or behavior was considered similar among the drugs studied despite their varying mechanisms of action suggesting the risk applies to all AEDs used for any indication. Additionally, the risk did not vary substantially by age.

Very common (10% or more): Diplopia (28%), blurred vision (16%)

Common (1% to 10%): Vision abnormality, nystagmus, photosensitivity, amblyopia

Uncommon (0.1% to 1%): Abnormality of accommodation, conjunctivitis, dry eyes, photophobia

Rare (less than 0.1%): Lacrimation disorder, oscillopsia, ptosis, strabismus, uveitis, visual field defect

Very common (10% or more): Vomiting (20%), nausea (19%), diarrhea (10%)

Common (1% to 10%): Abdominal pain, vomiting, dyspepsia, constipation, anorexia, dry mouth, rectal hemorrhage, peptic ulcer, flatulence

Uncommon (0.1% to 1%): Dysphagia, eructation, gastritis, gingivitis, increased appetite, increased salivation, mouth ulceration

Rare (less than 0.1%): Gastrointestinal hemorrhage, glossitis, gum hemorrhage, gum hyperplasia, hematemesis, hemorrhagic colitis, melena, stomach ulcer, stomatitis, tongue edema

Very rare (less than 0.01%): Pancreatitis, esophagitis

Very common (10% or more): Rhinitis (14%)

Common (1% to 10%): Pharyngitis, increased cough, epistaxis, dyspnea, bronchitis, sinusitis, bronchospasm

Uncommon (0.1% to 1%): Yawn

Rare (less than 0.1%): Hiccup, hyperventilation

Postmarketing reports: Apnea

In adult patients (n=3348), serious rash associated with hospitalization and discontinuation was reported in 0.3% of patients in premarketing epilepsy trials. In bipolar trials, serious rash occurred in 0.08% of patients receiving this drug as initial monotherapy and 0.13% of patients receiving this drug as adjunctive therapy. In worldwide postmarketing experience, rash-related death has been reported, but the numbers are too few to permit a precise estimate of rate.

In a prospectively followed cohort of pediatric patients 2 to 17 years old, the incidence of serious rash was approximately 0.3% to 0.8%. In a prospectively followed cohort of patients 2 to 16 years old (n=1983), 1 rash-related death occurred in a patient with epilepsy taking this drug as adjunctive therapy.

Evidence has show the inclusion of valproate in a multidrug regimen increases the risk of serious, potentially life-threatening rash in both adult and pediatric patients. In pediatric patients who used valproate concomitantly for epilepsy, 1.2% (6 of 482) experienced a serious rash (placebo=0.6%). In adults, 1% of patients of patients receiving this drug in combination with valproate (n=584) experienced a rash (placebo=0.16%).

Very common (10% or more): Rash (14%)

Common (1% to 10%): Contact dermatitis, dry skin, sweating, eczema, pruritus

Uncommon (0.1% to 1%): Acne, alopecia, hirsutism, maculopapular rash, skin discoloration, urticaria, ecchymosis, leukopenia

Rare (less than 0.1%): Angioedema, erythema, exfoliative dermatitis, fungal dermatitis, herpes zoster, leukoderma, multiforme erythema, petechial rash, pustular rash, Stevens-Johnson syndrome, vesiculobullous rash, anemia, eosinophilia, fibrin decrease, fibrinogen decrease, iron deficiency anemia, leukocytosis, lymphocytosis, macrocytic anemia, thrombocytopenia

Common (1% to 10%): Dysmenorrhea, vaginitis, amenorrhea, libido increase, urinary tract infection (both male and female), urinary frequency

Uncommon (0.1% to 1%): Libido decreased, abnormal ejaculation, hematuria, impotence, menorrhagia, polyuria, urinary incontinence

Rare (less than 0.1%): Anorgasmia, breast abscess, breast neoplasm, creatinine increase, cystitis, dysuria, epididymitis, female lactation, nocturia, urinary retention, urinary urgency

Very common (10% or more): Fever (15%), accidental injury (14%)

Common (1% to 10%): Fatigue

Uncommon (0.1% to 1%): Ear pain, taste perversion, tinnitus

Rare (less than 0.1%): Alcohol intolerance, deafness, taste loss, parosmia, taste loss

Common (1% to 10%): Weight decrease, weight gain, peripheral edema, facial edema

Rare (less than 0.1%): Bilirubinemia, general edema, gamma glutamyl transpeptidase increase, hyperglycemia

Common (1% to 10%): Neck pain, arthralgia, myalgia, decreased reflexes, back pain, increased reflexes, asthenia

Uncommon (0.1% to 1%): Arthritis, leg cramps, myasthenia, twitching

Rare (less than 0.1%): Bursitis, muscle atrophy, pathological fracture, tendinous contracture

Postmarketing reports: Rhabdomyolysis (among patients experiencing hypersensitivity reactions)

Common (1% to 10%): Chest pain, migraine

Uncommon (0.1% to 1%): Flushing, hot flashes, hypertension, palpitations, postural hypotension, syncope, tachycardia, vasodilation

Postmarketing reports: Agranulocytosis, hemolytic anemia, lymphadenopathy not associated with hypersensitivity disorder

Common (1% to 10%): Lymphadenopathy

Uncommon (0.1% to 1%): Liver function tests abnormal, aspartate transaminase (AST) increased

Rare (less than 0.1%): Hepatitis, alanine transaminase ALT) increased, acute kidney failure, kidney failure, kidney pain