What the label lists and what reports show
Lamotrigine side effects
Lamotrigine's FDA label: “Most common adverse reactions (incidence ≥10%) in adults were dizziness, headache, diplopia, ataxia, nausea, blurred vision, somnolence, rhinitis, pharyngitis, and rash.” FAERS holds 130,994 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 rash (8,633 reports).
- Generic listed
- A presentation discontinued
- Boxed warning
Check it at the source: the lamotrigine FDA label on DailyMed (effective October 10, 2025); 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 LAMICTAL?LAMICTAL can cause serious side effects. See “What is the most important information I should know about LAMICTAL?” Common side effects of LAMICTAL include: • dizziness • tremor • headache • rash • blurred or double vision • fever • lack of coordination • abdominal pain • infections, including seasonal flu • sleepiness • back pain • nausea, vomiting • diarrhea • tiredness • insomnia • dry mouth • stuffy nose • sore throat These are not all the possible side effects of LAMICTAL. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Source: FDA drug label, GlaxoSmithKline LLC, effective October 10, 2025 (SPL set d7e3572d-56fe-4727-2bb4-013ccca22678), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions (incidence ≥10%) in adults were dizziness, headache, diplopia, ataxia, nausea, blurred vision, somnolence, rhinitis, pharyngitis, and rash.
Table 8. Adverse Reactions in Pooled, Placebo-Controlled Adjunctive Trials in Adult Patients with Epilepsy Adverse reactions that occurred in at least 2% of patients treated with lamotrigine and at a greater incidence…
This table is printed in the Lamotrigine label published by Sun Pharmaceutical Industries, Inc. of June 3, 2026; the label quoted above does not print one.
| Body System/Adverse Reaction | Percent of Patients Receiving Adjunctive Lamotrigine (n = 711) | Percent of Patients Receiving Adjunctive Placebo (n = 419) |
|---|---|---|
| Headache | 29 | 19 |
| Flu syndrome | 7 | 6 |
| Fever | 6 | 4 |
| Abdominal pain | 5 | 4 |
| Neck pain | 2 | 1 |
| Reaction aggravated (seizure exacerbation) | 2 | 1 |
| Nausea | 19 | 10 |
| Vomiting | 9 | 4 |
| Diarrhea | 6 | 4 |
| Dyspepsia | 5 | 2 |
| Constipation | 4 | 3 |
| Anorexia | 2 | 1 |
| Arthralgia | 2 | 0 |
| Dizziness | 38 | 13 |
| Ataxia | 22 | 6 |
| Somnolence | 14 | 7 |
| Incoordination | 6 | 2 |
| Insomnia | 6 | 2 |
| Tremor | 4 | 1 |
| Depression | 4 | 3 |
| Anxiety | 4 | 3 |
| Convulsion | 3 | 1 |
| Irritability | 3 | 2 |
| Speech disorder | 3 | 0 |
| Concentration disturbance | 2 | 1 |
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 in more detail in the Warnings and Precautions section of the labeling: • Serious Skin Rashes [see Warnings and Precautions ( 5.1 )] • Hemophagocytic Lymphohistiocytosis [see Warnings and Precautions ( 5.2 )] • Multiorgan Hypersensitivity Reactions and Organ Failure [see Warnings and Precautions ( 5.3 )] • Cardiac Rhythm and Conduction Abnormalities [see Warnings and Precautions ( 5.4 )] • Blood Dyscrasias [see Warnings and Precautions ( 5.5 )] • Suicidal Behavior and Ideation [see Warnings and Precautions ( 5.6 )] • Aseptic Meningitis [see Warnings and Precautions ( 5.7 )] • Withdrawal Seizures [see Warnings and Precautions ( 5.10 )] • Status Epilepticus [see Warnings and Precautions ( 5.11 )] Epilepsy: Most common adverse reactions (incidence ≥10%) in adults were dizziness, headache, diplopia, ataxia, nausea, blurred vision, somnolence, rhinitis, pharyngitis, and rash. Additional adverse reactions (incidence ≥10%) reported in children included vomiting, infection, fever, accidental injury, diarrhea, abdominal pain, and tremor. ( 6.1 ) Bipolar disorder: Most common adverse reactions (incidence >5%) in adults were nausea, insomnia, somnolence, back pain, fatigue, rash, rhinitis, abdominal pain, and xerostomia.
Source: FDA drug label, GlaxoSmithKline LLC, effective October 10, 2025 (SPL set d7e3572d-56fe-4727-2bb4-013ccca22678), via openFDA; the full label on DailyMed
What do FAERS reports show?
130,994 reports list lamotrigine among the medicines taken, each a report of something that happened, not proof the medicine caused it; 11,279 are coded as a death and 40,119 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 16 reactions below, 11 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?
- Lamotrigine: 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